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Influenza Virus Vaccine Inactivated

Class: Vaccines
VA Class: IM100
Brands: Afluria, Fluad, Fluarix, Flucelvax, Flulaval, Fluzone

Medically reviewed by Drugs.com. Last updated on Sep 7, 2020.

Introduction

Inactivated virus vaccine.104 106 107 108 160 170 186 190 Seasonal influenza vaccine inactivated (IIV) contains noninfectious, suitably inactivated influenza virus types A and B subunits representing influenza strains likely to circulate in the US during the upcoming influenza season and is used to stimulate active immunity to influenza strains contained in the vaccine.100 104 106 107 108 160 170 186 190

Uses for Influenza Virus Vaccine Inactivated

Prevention of Seasonal Influenza A and B Virus Infections

Prevention of seasonal influenza virus infection in adults,104 106 107 108 160 170 186 190 adolescents,104 106 107 108 190 children,104 106 107 108 and infants ≥6 months of age.104 106 107 108

Influenza is an acute viral infection; influenza viruses spread from person to person mainly through large-particle respiratory droplet transmission.100 166 In the US, annual epidemics of seasonal influenza occur, usually during the fall or winter.100 Influenza viruses can cause illness in any age group; children have highest rate of infection.100 166 Influenza can exacerbate underlying medical conditions or lead to pneumonia in certain individuals.100 166 Adults ≥65 years of age, children <2 years of age, and individuals with chronic medical conditions have highest risk of influenza-related complications and death.100 166

Annual vaccination is the primary means of preventing seasonal influenza and its complications.100 Annual influenza vaccination necessary since immunity declines in the year following vaccination and circulating influenza strains change from year to year.100

CDC Advisory Committee on Immunization Practices (ACIP), AAP, and others recommend routine influenza vaccination for all adults, adolescents, children, and infants ≥6 months of age using an age-appropriate seasonal influenza vaccine, unless contraindicated.100 112 199 200 235 Vaccination against seasonal influenza recommended for otherwise healthy individuals as well as those who have medical conditions that put them at increased risk for influenza-related complications.100 112 Seasonal influenza vaccination is particularly important for individuals at increased risk for severe influenza or influenza-related complications and those who live with or care for such individuals (e.g., health-care personnel, household or other close contacts).100 Focus vaccination efforts on these individuals, especially when supplies of seasonal influenza vaccine are limited.100 (See Table 1.)

Table 1. ACIP and AAP Recommend Target Groups for Seasonal Influenza Vaccination Efforts Using an Appropriate Vaccine:100112

Infants and children 6 through 59 months of age

Adults ≥50 years of age

Adults, adolescents, and children ≥6 months of age with chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus)

Adults, adolescents, and children ≥6 months of age who are immunosuppressed, including those receiving immunosuppressive drugs and those with HIV infection

Women who are or will be pregnant during the influenza season

Children and adolescents 6 months through 18 years of age receiving long-term aspirin therapy who might therefore be at risk for Reye’s syndrome after influenza infection

Adults, adolescents, and children ≥6 months of age who are residents of nursing homes and other chronic-care facilities

American Indians and Alaska Natives

Morbidly obese individuals (body mass index ≥40)

Health-care personnel

Household contacts (including children ≥6 months of age) and caregivers of children <5 years of age (especially contacts of infants <6 months of age)

Household contacts (including children ≥6 months of age) and caregivers of adults ≥50 years of age

Household contacts (including children ≥6 months of age) and caregivers of individuals with medical conditions that put them at high risk for severe influenza complications

Several different types of influenza vaccines may be available in the US for prevention of seasonal influenza: influenza vaccine inactivated (IIV), influenza vaccine recombinant (RIV), and influenza vaccine live intranasal (LAIV).100 Influenza vaccine inactivated is available as quadrivalent formulations containing antigens representing 2 influenza A strains (H1N1 and H3N2) and 2 influenza B strains (B/Victoria lineage and B/Yamagata lineage)100 104 106 107 108 186 190 and may also be available as a trivalent formulation containing antigens representing the same 2 influenza A strains (H1N1 and H3N2) and a single influenza B strain (B/Victoria lineage).100 170 Influenza vaccine live intranasal and influenza vaccine recombinant are only available as quadrivalent formulations.100

Select specific seasonal influenza vaccine based on individual’s age and whether they have certain underlying medical conditions that put them at increased risk of influenza complications (e.g., pregnancy, immunocompromising disease or therapy), are in close contact with severely immunocompromised individuals, or have a personal history that contraindicates use of certain vaccines (e.g., egg allergy).100 112 For many individuals, more than one vaccine type may be appropriate.100 112

ACIP and AAP state that there are no preferential recommendations for any specific vaccine type or trade name, provided an age-appropriate vaccine is chosen based on FDA-labeled indications and contraindications.100 112 114 ACIP and AAP do not state a preference for a quadrivalent or trivalent formulation.100 112 If an age-appropriate vaccine is available and there are no contraindications, do not delay influenza vaccination to obtain a specific product.100 112

Influenza vaccine inactivated has several advantages over other available vaccine types because it can be used in the broadest range of patients, including those who cannot receive the recombinant influenza vaccine (e.g., infants and children 6 months through 17 years of age) and those who cannot receive the live intranasal influenza vaccine (e.g., infants and children 6 through 23 months of age, adults ≥50 years of age, pregnant women, children and adolescents receiving long-term aspirin therapy, individuals with underlying medical conditions that predispose them to severe disease following influenza infection, individuals with altered immunocompetence including those receiving immunosuppressive therapy, individuals who have close contact with severely immunocompromised individuals, individuals who have received other live virus vaccines within the past 4 weeks or are receiving antivirals for treatment or prevention of influenza).100 112 134

Although most inactivated influenza vaccines are egg-based,104 106 107 108 160 170 186 a quadrivalent cell culture-based inactivated vaccine (Flucelvax; ccIIV) also is available.190

In addition to conventional inactivated influenza vaccines, quadrivalent and trivalent adjuvant-containing inactivated influenza vaccines (Fluad; aIIV) are available for use only in adults ≥65 years of age.170 186 The adjuvant is MF59C.1 (MF59), a squalene-based oil-in-water emulsion170 186 included to increase antibody response.569

A quadrivalent preparation containing a higher antigen content (Fluzone High-Dose) than that contained in standard-dose inactivated influenza vaccines is commercially available for use only in adults ≥65 years of age.100 160

Health-care personnel and individuals training for health-care professions: ACIP and the Healthcare Infection Control Practices Advisory Committee (HICPAC) recommend routine annual vaccination for all such individuals, unless contraindicated.100 235 This includes physicians, nurses, and other personnel in both inpatient and outpatient care settings, medical emergency response workers (e.g., paramedics, emergency medical technicians), employees of nursing homes and long-term care facilities who have contact with patients or residents, and students in these professions who will have contact with patients.100 235

Travelers: All travelers (including those at high risk for influenza complications) who were not vaccinated with the current seasonal influenza vaccine should consider vaccination against seasonal influenza ≥2 weeks before travel.100 115 Revaccination not recommended for travelers who received influenza vaccine during the preceding fall and will be traveling during the summer.115 Risk for exposure to seasonal influenza during travel depends on time of year and destination.115 In temperate regions, influenza typically circulates at higher levels during colder winter months (i.e., October to May in Northern Hemisphere and April to September in Southern Hemisphere).100 115 In many tropical and subtropical areas, influenza can occur throughout the year.100 115

HIV-infected individuals: ACIP, CDC, NIH, IDSA, AAP, and others recommend annual vaccination against seasonal influenza for all HIV-infected adults, adolescents, children, and infants ≥6 months of age since such individuals may be at increased risk for influenza-related complications.100 112 155 156 However, antibody response may be reduced in HIV-infected individuals and is inversely correlated with severity of the disease.100 105 116 156 232 233 310 376 376 Use age-appropriate influenza vaccine inactivated or influenza vaccine recombinant (not intranasal live influenza vaccine) in HIV-infected individuals.100 112 135 155 156 (See Individuals with Altered Immunocompetence under Cautions.)

HSCT candidates: CDC, IDSA, and American Society of Blood and Marrow Transplantation (ASBMT) state give seasonal influenza vaccine inactivated for the influenza season prior to HSCT and then annually thereafter, beginning ≥6 months after HSCT.134 409

Seasonal influenza vaccines not effective against all strains of influenza, but may be effective against those strains (and possibly closely related strains) represented in the vaccine.100 166 (See Limitations of Vaccine Effectiveness under Cautions.)

Current information regarding influenza surveillance and updated recommendations for prevention and treatment of seasonal influenza is available from CDC at [Web].

Influenza Vaccination During the Coronavirus Disease 2019 (COVID-19) Pandemic

CDC and ACIP state that efforts to ensure influenza vaccination for all individuals ≥6 months of age for the 2020–2021 influenza season are of paramount importance to reduce influenza-related morbidity and mortality and reduce the impact of respiratory illnesses in the population and the resulting burdens on the health-care system.100 583 SARS-CoV-2 (causative agent of COVID-19) is expected to circulate in the US during the 2020–2021 influenza season; the extent of continued or recurrent SARS-CoV-2 circulation during the time influenza viruses are circulating is not known.100 Vaccination against influenza can reduce prevalence of influenza illness and reduce incidence of influenza symptoms that might be confused with COVID-19 symptoms (i.e., fever, cough, dyspnea).100 In addition, prevention of influenza and reduction in severity of influenza illness and associated outpatient visits, hospitalizations, and intensive care unit admissions could alleviate stress on the US health-care system.100

Health-care providers should use every opportunity to communicate the importance of influenza vaccination and to administer an age-appropriate influenza vaccine to all eligible individuals for the 2020–2021 influenza season.100 583 This includes essential workers (e.g., health-care personnel such as nursing home, long-term care facility, and pharmacy staff, and other critical infrastructure workforce personnel), those at increased risk for severe illness due to COVID-19 (e.g., adults ≥65 years of age, residents in nursing homes or long-term care facilities, individuals with certain underlying medical conditions), and those at high risk for influenza complications (e.g., infants and young children, children with neurologic conditions, pregnant women, adults ≥65 years of age).583

Stay-at-home orders and social distancing strategies aimed at reducing SARS-CoV-2 transmission have led to decreased use of routine preventive medical services, including immunization services.583 Routine vaccination is an essential preventive care service for children, adolescents, and adults (including pregnant women) that should not be delayed because of the COVID-19 pandemic.583 Ensuring that immunization services are maintained or reinitiated is essential for protecting individuals and communities from vaccine-preventable diseases and outbreaks and reducing the burden of respiratory illness during the 2020–2021 influenza season.583 Some settings usually used to provide influenza vaccination (e.g., workplaces) may not be available as a result of strategies used to limit spread of COVID-19581 and influenza vaccination programs may need to adapt and consider different or additional vaccination strategies for the 2020–2021 influenza season.100 583 (See General under Dosage and Administration.)

Guidance for vaccination planning and interim guidance for administering routine immunizations, including influenza vaccine, during the COVID-19 pandemic is available at [Web].583

Influenza Virus Vaccine Inactivated Dosage and Administration

General

Administer seasonal influenza vaccine every year before exposure to seasonal influenza.100 In the US, localized influenza outbreaks indicating start of annual influenza season can occur as early as October and peak influenza activity (which often is close to the midpoint of influenza activity for the season) usually occurs in January or February or later.100

ACIP recommends offering influenza vaccination by the end of October, if possible, and continuing to offer vaccination as long as influenza viruses are circulating and unexpired vaccine is available.100 Although influenza vaccination by the end of October is recommended, vaccination in December or later (even if influenza activity has begun) is likely to be beneficial in the majority of influenza seasons.100

When 2 doses of influenza vaccine are required in children 6 months through 8 years of age, give first dose as soon as possible after vaccine becomes available since this allows second dose to be given by the end of October.100 For children and adults requiring only a single dose of influenza vaccine, there is some evidence that early vaccination (i.e., in July or August) is likely to be associated with suboptimal immunity (waning immunity) before end of influenza season, particularly in older adults.100 Community vaccination programs should balance maximizing likelihood of persistence of vaccine-induced protection through the season with avoiding missed opportunities for vaccination or vaccinating after influenza circulation has already started, especially in those ≥65 years of age.100

Because SARS-CoV-2 (causative agent of COVID-19) is expected to be circulating in the US at the same time influenza viruses are circulating, it is important that health-care providers use every opportunity to communicate the importance of influenza vaccination and to administer an age-appropriate influenza vaccine to all eligible individuals for the 2020–2021 influenza season.100 583 (See Influenza Vaccination During the Coronavirus Disease 2019 [COVID-19] Pandemic under Uses.) Some settings usually used to provide influenza vaccination (e.g., workplaces) may not be available as a result of strategies used to limit spread of COVID-19.581 In addition, organized influenza vaccination programs may need to adapt and consider different or additional vaccination strategies for the 2020–2021 influenza season, including starting vaccination campaigns early to allow sufficient time to vaccinate the population and avoid missed opportunities for influenza vaccination, using alternative vaccination sites (e.g., drive-through, curbside, mobile outreach units, home visits), and extending the duration of vaccination campaigns.100 583

Guidance for vaccination planning and interim guidance for administering routine immunizations, including influenza vaccine, during the COVID-19 pandemic is available at [Web].583

Administration

Afluria (quadrivalent), Fluad (quadrivalent, trivalent), Fluarix (quadrivalent), Flucelvax (quadrivalent), Flulaval (quadrivalent), Fluzone (quadrivalent), Fluzone High-Dose (quadrivalent): Administer only by IM injection.104 106 107 108 160 170 186 190

Do not administer intradermally,104 106 107 190 IV,104 106 107 160 190 or sub-Q.104 106 107 190

As an alternative to IM injection using a needle and syringe, Afluria (quadrivalent) may be administered IM using a PharmaJet Stratis needle-free injection system only in adults 18 through 64 years of age.108 543 Do not administer other commercially available inactivated influenza vaccines using a jet injector.543

Syncope (vasovagal or vasodepressor reaction; fainting) may occur following vaccination; such reactions occur most frequently in adolescents and young adults.134 Take appropriate measures to decrease risk of injury if patient becomes weak or dizzy or loses consciousness (e.g., have vaccinees sit or lie down during and for 15 minutes after vaccination).134 If syncope occurs, observe patient until symptoms resolve.134

May be given concurrently with other age-appropriate vaccines.100 134 When multiple vaccines administered during a single health-care visit, give each parenteral vaccine using separate syringes and different injection sites.134 Separate injection sites by ≥1 inch (if anatomically feasible) to allow appropriate attribution of any local adverse effects that may occur.134

IM Administration

Depending on patient age, administer IM into deltoid muscle or anterolateral thigh.134

Infants 6 through 11 months of age: Preferably give IM injection into anterolateral thigh.100 104 106 107 134 In certain circumstances (e.g., physical obstruction at other sites and no reasonable indication to defer the vaccine dose), may consider IM injection into gluteal muscle using care to identify anatomic landmarks prior to injection.134

Infants and children 1 through 2 years of age: Preferably give IM injection into anterolateral thigh;134 alternatively, deltoid muscle can be used if muscle mass is adequate.134

Adults, adolescents, and children ≥3 years of age: Preferably give IM injection into deltoid muscle;100 104 106 107 108 134 160 170 190 alternatively, anterolateral thigh can be used.134

Do not administer into gluteal region or any area where there may be a major nerve trunk.104 106 107 160 170 190

To ensure delivery into muscle, make IM injections at a 90° angle to the skin using a needle length appropriate for individual’s age and body mass, thickness of adipose tissue and muscle at injection site, and injection technique.134 Consider anatomic variability, especially in the deltoid; use clinical judgment to avoid inadvertent underpenetration or overpenetration of muscle.134

Do not mix with any other vaccine or solution.104 134 160 186 190

Shake prefilled syringe before administering a dose.104 106 107 108 160 170 186 190

Shake vaccine vial before withdrawing a dose.104 107 108

Discard vaccine if it contains particulates, appears discolored, or cannot be resuspended with thorough agitation.104 106 107 108 160 190

Jet Injector (Afluria)

Afluria (quadrivalent) may be administered IM using a PharmaJet Stratis needle-free injection system in adults 18 through 64 years of age.108 Do not use jet injector to administer Afluria in children and adolescents <18 years of age or geriatric adults ≥65 years of age.108

Consult manufacturer’s information for the jet injector for specific information on how to administer Afluria using the PharmaJet Stratis needle-free injection system.108

Dosage

Dose and dosing schedule (i.e., number of doses) for prevention of seasonal influenza depend on individual’s age, vaccination history, and specific product administered.100 104 106 107 108 112 160 170 186 190

Pediatric Patients

Prevention of Seasonal Influenza A and B Virus Infections
Infants and Children 6 through 35 Months of Age (Afluria)
IM

Available in 0.25-mL single-dose syringes to provide a reduced dose for use in infants and children 6 through 35 months of age.108

Has not previously received any doses of any seasonal influenza vaccine or has an uncertain history regarding influenza vaccination: Two 0.25-mL doses administered at least 1 month (4 weeks) apart.100 108 112

Did not receive a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend two 0.25-mL doses administered at least 4 weeks apart.100 112

Received a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend a single 0.25-mL dose.100 112

Infants and Children 6 through 35 Months of Age (Fluarix, Flulaval)
IM

Has not previously received any doses of any seasonal influenza vaccine or has an uncertain history regarding influenza vaccination: Two 0.5-mL doses administered at least 1 month (4 weeks) apart.100 106 107 112

Did not receive a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend two 0.5-mL doses administered at least 4 weeks apart.100 112

Received a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend a single 0.5-mL dose.100 112

Infants and Children 6 through 35 Months of Age (Fluzone)
IM

Available in 0.25-mL single-dose syringes to provide a reduced dose for use in infants and children 6 through 35 months of age.104 112 Alternatively, standard doses (0.5 mL) may be used to this age group.100 104 112

Has not previously received any doses of any seasonal influenza vaccine or has an uncertain history regarding influenza vaccination: Manufacturer recommends two 0.25-mL doses, two 0.5-mL doses, or one 0.25- and one 0.5-mL dose administered at least 1 month (4 weeks) apart.100 104 112

Did not receive a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend two 0.25-mL doses or two 0.5-mL doses administered at least 4 weeks apart.100 112

Received a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend a single 0.25- or 0.5-mL dose.100 112

Children 3 through 8 Years of Age (Afluria, Fluarix, Flulaval, Fluzone) or Children 4 through 8 Years of Age (Flucelvax)
IM

Has not previously received any doses of any seasonal influenza vaccine or has an uncertain history regarding influenza vaccination: Two 0.5-mL doses administered at least 1 month (4 weeks) apart.100 104 106 107 108 112 190

Did not receive a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend two 0.5-mL doses administered at least 4 weeks apart.100 112

Received a total of ≥2 doses of any seasonal influenza vaccine before July 1, 2020: ACIP and AAP recommend a single 0.5-mL dose.100 112

Children and Adolescents 9 through 17 Years of Age (Afluria, Fluarix, Flucelvax, Flulaval, Fluzone)
IM

Single 0.5-mL dose.100 104 106 107 108 112 190

Adults

Prevention of Seasonal Influenza A and B Virus Infections
Adults ≥18 Years of Age (Afluria, Fluarix, Flucelvax, Flulaval, Fluzone)
IM

Single 0.5-mL dose.100 104 106 107 108 190 (See Geriatric Use under Cautions.)

Special Populations

Hepatic Impairment

No specific dosage recommendations.104 106 107 108 190

Renal Impairment

No specific dosage recommendations.104 106 107 108 190

Geriatric Patients

A standard-dose IM preparation or IM Fluzone High-Dose may be used.100 (See Geriatric Use under Cautions.)

Standard-dose Preparations (Afluria, Fluarix, Flucelvax, Flulaval, Fluzone)

Geriatric adults ≥65 years of age: Single 0.5-mL IM dose.104 106 107 108 190

Standard-Dose, Adjuvant-containing Preparation (Fluad)

Geriatric adults ≥65 years of age: Single 0.5-mL IM dose.170

Fluzone High-Dose

Geriatric adults ≥65 years of age: Single 0.7-mL IM dose.160

Cautions for Influenza Virus Vaccine Inactivated

Contraindications

  • History of severe hypersensitivity (e.g., anaphylaxis) to previous dose of any influenza vaccine.104 106 107 108 160 170 186

  • History of severe hypersensitivity (e.g., anaphylaxis) to any component of the vaccine, including egg protein.104 106 107 108 112 160 186 190 (See Sensitivity Reactions under Cautions.)

Warnings/Precautions

Sensitivity Reactions

Allergic or immediate hypersensitivity reactions (e.g., urticaria, angioedema, anaphylaxis, anaphylactic shock, serum sickness, allergic asthma) reported rarely.100 104 106 107 108 170

Prior to administration, review patient’s history with respect to possible sensitivity reactions to the vaccine or vaccine components, including egg protein, and prior vaccination-related adverse effects and assess benefits versus risks.100 106 107 108 112

Administer in a setting where appropriate medical treatment and supervision are available to manage possible anaphylactic reactions if they occur.100 104 106 107 108 112 134 160 170 186 190 Epinephrine and other appropriate agents should be readily available.

Do not administer additional vaccine doses to any individual who experienced severe or life-threatening reactions to a previous dose.100 (See Contraindications under Cautions.)

Egg Allergy

Most seasonal inactivated influenza vaccines (Afluria, Fluad, Fluarix, Flulaval, Fluzone) are produced using embryonated chicken eggs;100 104 106 107 108 112 160 170 186 these vaccines can contain residual egg protein (ovalbumin).106 107 170 186

Flucelvax inactivated influenza vaccine (quadrivalent) is cell culture-based and prepared using virus propagated in Madin Darby Canine Kidney (MDCK) cells (not embryonated chicken eggs).100 112 190

Manufacturers of egg-based inactivated influenza vaccines state that these vaccines are contraindicated in individuals who have had a severe allergic reaction (e.g., anaphylaxis) to egg protein.104 106 107 108 160 170 186

ACIP states that individuals with history of egg allergy involving only urticaria after exposure to eggs may receive any licensed and recommended influenza vaccine that is appropriate based on age and health status, including those produced using eggs.100

ACIP states that individuals with history of egg allergy involving symptoms other than urticaria (e.g., angioedema or swelling, respiratory distress, lightheadedness, recurrent emesis, reactions requiring epinephrine or another emergency medical intervention) also may receive any licensed and recommended influenza vaccine that is appropriate based on age and health status; however, if an egg-based influenza vaccine is used, it should be administered in an inpatient or outpatient medical setting (including but not necessarily limited to hospitals, clinics, health departments, and physician offices) under supervision of a health-care provider able to recognize and manage severe allergic reactions.100

A previous severe allergic reaction to influenza vaccine, regardless of the component suspected of being responsible for the reaction, is a contraindication to future receipt of influenza vaccine.100 112 (See Contraindications under Cautions.)

Neomycin and/or Polymyxin B Allergy

Afluria (quadrivalent): Each 0.5-mL dose contains neomycin sulfate (≤81.8 ng) and polymyxin B (≤14 ng).108

Fluad adjuvant-containing (quadrivalent and trivalent): Each 0.5-mL dose may contain trace amounts of neomycin (≤0.02 mcg by calculation) and kanamycin (≤0.03 mcg by calculation).170 186

Neomycin hypersensitivity usually manifests as a delayed-type (cell-mediated) contact dermatitis.134

ACIP states that a history of delayed-type allergic reaction to neomycin is not a contraindication to use of vaccines containing trace amounts of neomycin.134 However, before giving a neomycin-containing vaccine to an individual with a history of anaphylactic reaction to neomycin, have patient evaluated by an allergist.134

Thimerosal Allergy

All multiple-dose vials of influenza vaccine inactivated (Afluria, Flucelvax, Fluzone) contain thimerosal as a preservative.104 108 190 (See Thimerosal Precautions under Cautions.)

Hypersensitivity reactions to thimerosal contained in vaccines have been reported in some individuals.140 498 500 These reactions usually manifest as local, delayed-type hypersensitivity reactions (e.g., erythema, swelling),100 134 140 427 but a generalized reaction manifested as pruritus and an erythematous, maculopapular rash on all 4 extremities has been reported rarely.500

Even when patch or intradermal tests for thimerosal sensitivity are positive, most individuals do not develop hypersensitivity reactions to thimerosal administered as a component of vaccines.100 134 140

ACIP states that a history of delayed-type hypersensitivity to thimerosal is not a contraindication to use of vaccines that contain thimerosal.134

Guillain-Barré Syndrome (GBS)

If GBS occurred within 6 weeks after previous influenza vaccination, manufacturers state base decision to administer influenza vaccine on careful consideration of potential benefits and risks.104 106 107 108 160 170 186 190

The 1976 swine influenza vaccine was associated with increased frequency of GBS.104 106 107 108 160 170 186 190 278 279 364 365 Evidence for causal relationship between other influenza vaccines and GBS inconclusive;104 106 107 108 160 170 190 if an excess risk exists, it probably is slightly more than 1 additional case of GBS per 1 million vaccinees).104 106 107 108 160 170 186 190 364 365

ACIP states that, as a precaution, individuals who are not at high risk for severe influenza complications and who developed GBS within 6 weeks of a previous dose of influenza vaccine generally should not receive influenza vaccination;100 clinicians might consider use of antiviral prophylaxis for such individuals.100 However, ACIP states that the benefits of influenza vaccine may outweigh the risks for certain individuals with a history of GBS within 6 weeks after a previous dose of influenza vaccine who are at high risk for severe complications from influenza.100

Individuals with Altered Immunocompetence

May be administered to individuals immunosuppressed as the result of disease or immunosuppressive therapy.100 Consider possibility that immune response to the vaccine and efficacy may be reduced in these individuals.100 160 170 186 190

ACIP, CDC, NIH, IDSA, AAP, and others state that HIV-infected adults, adolescents, children, and infants ≥6 months of age should receive annual vaccination against seasonal influenza; use age-appropriate parenteral inactivated influenza vaccine (not intranasal live vaccine) for prevention of seasonal influenza in HIV-infected individuals.100 112 155 156 Antibody response may be inversely correlated with severity of the disease.100 105 116 232 233 310 376 Use of an additional (i.e., booster) dose of influenza vaccine does not appear to improve immune response in HIV-infected individuals.116 124 232 310

May not be effective if given <6 months after HSCT.409

Generally, administer prior to initiation of immunosuppressive therapy or defer until immunosuppressive therapy discontinued.105 134 (See Immunosuppressive Agents under Interactions.)

Fever and Febrile Seizures

Febrile seizures reported rarely following administration of influenza vaccine inactivated.100 104 108 160

Postmarketing reports of increased rates of fever and febrile seizures in infants and children 6 months through 4 years of age and increased incidence of fever in children 5–8 years of age who received a 2010 Southern Hemisphere parenteral inactivated influenza vaccine100 534 that was antigenically equivalent to and produced by the same manufacturer as one of the 2010–2011 seasonal parenteral inactivated influenza vaccines marketed in the US (i.e., Afluria; CSL).534 The 2010 Southern Hemisphere formulation apparently induced a stronger inflammatory cytokine response than that associated with previous formulations of the vaccine or with other inactivated influenza viruses and this may have been mediated by higher concentrations of residual lipid and RNA remaining in the vaccine.100

Surveillance for febrile seizures following receipt of influenza vaccine inactivated is ongoing and is being conducted through VAERS ([Web]) and Vaccine Safety Datalink (VSD) ([Web]).100

Thimerosal Precautions

Although there is no convincing evidence that the low concentrations of thimerosal (a mercury-containing preservative) contained in some vaccines is harmful to vaccine recipients,100 493 494 499 501 502 503 504 505 506 efforts to eliminate or reduce the thimerosal content in vaccines is recommended as a prudent measure to reduce mercury exposure in infants and children and part of an overall strategy to reduce mercury exposures from all sources, including food and drugs.100 134 401 402 403 492

As a result of efforts initiated in 1999 to remove or reduce thimerosal in vaccines and expedite development and approval of preservative-free formulations of vaccines, inactivated influenza vaccine now is commercially available in prefilled single-dose syringes or single-dose vials as preservative-free formulations that do not contain thimerosal.104 106 107 108 160 170 190 427 Only multiple-dose vials of inactivated influenza virus still contain thimerosal as a preservative (≤ 25 mcg of mercury per 0.5-mL dose).104 107 108 190 427

Although it was suggested that thimerosal in vaccines theoretically could have adverse effects in vaccine recipients, there is no conclusive evidence that the low levels of thimerosal contained in vaccines cause harm in vaccine recipients.100 134 492 493 494 499 501 502 503 504 505 506 A link between thimerosal in vaccines and neurodevelopmental disorders in children (autism, attention deficit/hyperactivity disorder [ADHD], speech or language delay) possibly related to mercury neurotoxicity has been theorized; however, considerable evidence has accumulated that supports the absence of substantial risk for neurodevelopmental disorders or other harm resulting from exposure to thimerosal-containing vaccines.493 494 499 501 502 503 504 505 506 In 2004, the Immunization Safety Review Committee of the IOM examined the hypothesis that thimerosal-containing vaccines are causally associated with autism and concluded that the body of epidemiologic evidence favors rejection of a causal relationship between these vaccines and autism.506

Analysis of adverse effects reported to VAERS indicates that there is no difference in the incidence of injection site reactions, rash, or infections in infants 6–23 months of age who received preservative-containing (thimerosal-containing) inactivated influenza vaccine compared with those who received preservative-free preparations of the vaccine.497 To date, the only adverse effects known to be caused by thimerosal contained in vaccines are local hypersensitivity reactions.134 140 427 493 (See Thimerosal Allergy under Cautions.)

USPHS, ACIP, AAP, AAFP, and other experts state that use of vaccines that contain thimerosal is preferable to withholding vaccination since failure to provide protection against vaccine-preventable diseases may represent an immediate threat, especially in infants.401 402 403 AAP states that the benefits of protecting children outweigh the hypothetical risks associated with the minute amounts of thimerosal contained in some currently available influenza vaccine preparations.403

Afluria (quadrivalent): Commercially available in 0.5-mL prefilled syringes as a preservative-free formulation (thimerosal not used in manufacturing process).108 Also available in multiple-dose vials containing thimerosal as a preservative (24.5 mcg of mercury per 0.5-mL dose).108

Fluad adjuvant-containing (quadrivalent and trivalent): Commercially available in 0.5-mL prefilled syringes as a preservative-free formulation that does not contain thimerosal.170 186

Fluarix (quadrivalent): Commercially available in 0.5-mL prefilled syringes as a preservative-free formulation that does not contain thimerosal.106

Flucelvax (quadrivalent): Commercially available in 0.5-mL prefilled syringes as a preservative-free formulation (thimerosal was not used in the manufacturing process).190 Also available in multiple-dose vials that contain thimerosal as a preservative (25 mcg of mercury per 0.5-mL dose).190

Flulaval (quadrivalent): Commercially available in 0.5-mL prefilled syringes as a preservative-free formulation (thimerosal not used in manufacturing process).107

Fluzone (quadrivalent): Commercially available in 0.25- and 0.5-mL prefilled syringes and in 0.5-mL single-dose vials as a preservative-free formulation (thimerosal not used in manufacturing process).104 Also available in multiple-dose vials containing thimerosal as a preservative (25 mcg of mercury per 0.5-mL dose).104

Fluzone High-Dose (quadrivalent): Commercially available in 0.7-mL prefilled syringes as a preservative-free formulation.160

Individuals with Bleeding Disorders

Advise individuals and/or their family about the risk of hematoma from IM injections.134

ACIP states that vaccines may be given IM to such individuals if a clinician familiar with the patient’s bleeding risk determines that the preparation can be administered with reasonable safety.134 In these cases, use a fine needle (23 gauge or smaller) to administer the vaccine and apply firm pressure to the injection site (without rubbing) for ≥2 minutes.134 In individuals receiving therapy for hemophilia, IM vaccines can be scheduled for administration shortly after a dose of such therapy.134

Concomitant Illness

Base decision to administer or delay vaccination in an individual with a current or recent acute illness on severity of symptoms and etiology of the illness.134

ACIP states mild acute illness does not preclude vaccination.134

ACIP states moderate or severe acute illness (with or without fever) is a precaution for vaccination;134 defer vaccines until individual has recovered from the acute phase of the illness.134 This avoids superimposing vaccine adverse effects on the underlying illness or mistakenly concluding that a manifestation of the underlying illness resulted from vaccine administration.134

Individuals with Coronavirus Disease 2019 (COVID-19)

CDC states defer influenza vaccination in individuals with suspected or confirmed COVID-19, regardless of symptoms, until criteria for discontinuance of COVID-19 isolation have been met.583 Although mild illness usually not considered a contraindication to vaccination, postpone vaccination in such individuals with suspected or confirmed COVID-19 to avoid exposing health-care personnel and other patients to the disease.583

Limitations of Vaccine Effectiveness

Following seasonal influenza vaccination, up to 2 weeks may be required to develop antibody protection against infection.100

May not protect all vaccine recipients against influenza.104 106 107 108 160 170 186 190

Seasonal influenza vaccines are formulated annually to contain influenza A and B antigens predicted to represent strains of influenza virus likely to circulate in the US during the upcoming influenza season.100 Efficacy of seasonal influenza vaccine during any given year depends on how closely viral strains represented in the vaccine match viral strains circulating during the season.100 166

Seasonal influenza vaccines not expected to provide protection against human infection with animal-origin influenza viruses, including avian influenza A viruses (e.g., avian influenza A [H5N1], avian influenza A [H7N9]).115 149

Seasonal influenza vaccines will not provide protection against COVID-19.581

Duration of Immunity

Duration of immunity usually <1 year.166 Immunity declines during the year after seasonal influenza vaccination.100 108 166

Although some data indicate early vaccination (e.g., in July and August) might be associated with suboptimal immunity before end of the influenza season, particularly among older adults, revaccination later in the season not recommended for individuals who already received influenza vaccine for the 2020–2021 influenza season.100

Annual vaccination needed because of waning immunity and because circulating strains of influenza virus change from year to year.100 104 106 107 108

Do not administer influenza vaccine from a previous influenza season (e.g., 2019–2020) in an attempt to provide protection during a subsequent influenza season.100

Improper Storage and Handling

Improper storage or handling of vaccines may reduce vaccine potency resulting in reduced or inadequate immune responses in vaccinees.134

Inspect all vaccines upon delivery and monitor during storage to ensure that the appropriate temperature is maintained.134 (See Storage under Stability.)

Do not administer vaccine that has been mishandled or has not been stored at the recommended temperature.134

If there are concerns about mishandling, contact the manufacturer or state or local immunization or health departments for guidance on whether the vaccine is usable;134 also can consult CDC.134

Specific Populations

Pregnancy

Data insufficient to assess risk of administering influenza vaccine inactivated during pregnancy.104 106 107 108 160 170 186 190

Animal reproduction studies have not revealed evidence of harm to fetus.104 106 107 108 170 186 190

Pregnant women are at increased risk for influenza-related complications, which may lead to adverse pregnancy outcomes including preterm labor and delivery.104 106 107 190

ACIP, ACOG, and AAP recommend vaccination against influenza in all women who are pregnant or who might become pregnant during the influenza season;100 112 113 134 any licensed, age-appropriate, inactivated influenza vaccine (i.e., influenza vaccine inactivated or influenza vaccine recombinant) can be used.100 112 These experts state that inactivated influenza vaccine can be given at any time during pregnancy (any trimester) before or during the influenza season.100 112 113 134 Encourage unvaccinated postpartum women to receive vaccination before discharge from the hospital.112

ACIP states that there is no evidence of risk to the fetus if inactivated vaccines are administered during pregnancy.134

To monitor pregnancy outcomes and newborn health status following influenza vaccination of pregnant women, some manufacturers have established pregnancy registries.104 106 107 190 Women who receive the vaccine during pregnancy or their health-care providers may contact the manufacturer at 855-358-8966 (Afluria, Flucelvax),108 190 888-452-9622 (Fluarix, Flulaval),106 107 or 800-822-2463 (Fluzone).104

Lactation

Not known whether influenza vaccine inactivated distributed into milk.104 106 107 108 190 Data insufficient to assess effects on the breast-fed infant or on milk production.104 106 107 108 186 190

Consider benefits of breast-feeding and importance of the vaccine to the woman;104 106 107 108 190 also consider potential adverse effects on the breast-fed child from the vaccine or underlying maternal condition (i.e., susceptibility to influenza infection).104 106 107 108 190

ACIP and AAP state breast-feeding is not a contraindication to influenza vaccine inactivated.112 134 These experts state that inactivated vaccines do not pose any unusual risks for the mother or her nursing infant.112 134

Pediatric Use

Afluria, Fluarix, Flulaval, Fluzone: Safety and efficacy not established in infants <6 months of age.104 106 107 108

Flucelvax: Safety and efficacy not established in children <4 years of age.190

Fluad adjuvant-containing (quadrivalent and trivalent): Safety and efficacy not established in pediatric patients.170 186

Fluzone High-Dose: Safety and efficacy not established in pediatric patients.160

Because seasonal influenza vaccine inactivated not indicated in infants <6 months of age, all household and other close contacts (e.g., day-care providers) of infants <6 months of age should be vaccinated against seasonal influenza using vaccine appropriate for their age and target group since this may provide some protection against seasonal influenza for these young infants.100

Geriatric Use

Afluria, Fluarix, Flucelvax, Flulaval, Fluzone: No overall differences in safety relative to younger adults;104 106 107 190 may be less immunogenic in geriatric individuals.100 108 190

Fluad adjuvant-containing (quadrivalent and trivalent): Use only in adults ≥65 years of age.100 170 186 Safety profile of this standard-dose, adjuvant-containing vaccine similar to that of standard-dose, non-adjuvant-containing vaccine.100 Although some local and systemic adverse events reported more frequently with the adjuvant-containing vaccine, most adverse reactions have been mild in severity.100

Fluzone High-Dose (quadrivalent): Use only in adults ≥65 years of age.100 160 Each 0.7 mL of Fluzone High-Dose contains 4 times the amount of antigen contained in standard-dose Fluzone.100 160 In adults ≥65 years of age, higher incidence of injection site reactions and systemic adverse effects reported with trivalent Fluzone High-Dose (no longer available in US) compared with standard-dose Fluzone.100 Some evidence that the high-dose formulation elicits higher antibody titers and higher seroconversion rates than the standard-dose formulation in adults ≥65 years of age and may be more effective in preventing laboratory-confirmed influenza in this age group.100

ACIP states that all adults ≥65 years of age should be vaccinated against influenza using influenza virus vaccine inactivated or influenza vaccine recombinant.100 ACIP does not express a preference for Fluzone High-Dose or the standard-dose adjuvant-containing vaccine (Fluad) or any other inactivated influenza vaccine in this age group, and states that adults ≥65 years may receive a standard-dose preparation (Afluria, Fluad, Fluarix, Flucelvax, Flulaval, Fluzone) or Fluzone High-Dose.100 200

Common Adverse Effects

Injection site reactions (i.e., tenderness, pain, redness, induration, swelling), headache, fatigue, myalgia, fever, malaise.104 106 107 170 186 190

Interactions for Influenza Virus Vaccine Inactivated

Immunosuppressive Agents

Immune responses to vaccines, including influenza vaccine inactivated, may be reduced in individuals receiving immunosuppressive agents.104 105 106 107 108 134 160 170 190

Generally, give inactivated vaccines ≥2 weeks prior to initiation of immunosuppressive therapy and, because of possible suboptimal response, do not give during and for certain periods of time after immunosuppressive therapy discontinued.105 134 135 (See Specific Drugs under Interactions.)

Time to restoration of immune competence varies depending on type and intensity of immunosuppressive therapy, underlying disease, and other factors;105 optimal timing for vaccine administration after discontinuance of immunosuppressive therapy not identified for every situation.105

Vaccines

Although specific studies may not be available, concurrent administration with other age-appropriate vaccines, including live virus vaccines, toxoids, or inactivated or recombinant vaccines, during same health-care visit not expected to affect immunologic responses or adverse reactions to any of the preparations.100 105 134

Immunization with influenza vaccine inactivated can be integrated with immunization against diphtheria, tetanus, pertussis, Haemophilus influenzae type b (Hib), hepatitis A, hepatitis B, human papillomavirus (HPV), measles, mumps, rubella, meningococcal disease, pneumococcal disease, poliomyelitis, rotavirus, and varicella.100 105 134 However, administer each parenteral vaccine using separate syringes and different injection sites.134

Specific Drugs

Drug

Interaction

Comments

Anticoagulants (e.g., warfarin)

Increased INR, bleeding, epistaxis, and muscle hematoma reported rarely423

ACIP states influenza vaccine inactivated may be given to patients receiving warfarin;134 some clinicians suggest closely monitoring for enhanced anticoagulant effects423

Antivirals active against influenza (baloxavir, oseltamivir, peramivir, zanamivir, amantadine, rimantadine)

Baloxavir, peramivir: No specific studies406 410

Oseltamivir: No specific studies, but interference with antibody response to inactivated influenza vaccine not expected;407 oseltamivir does not interfere with humoral antibody response to influenza infection407

Zanamivir: No interference with antibody response to inactivated influenza vaccine408

Amantadine, rimantadine: Do not appear to interfere with antibody response to inactivated influenza vaccine120 122

Baloxavir, oseltamivir, peramivir, zanamivir: May be used concurrently with or at any interval before or after influenza vaccine inactivated100 112 134 406 407

Hepatitis B vaccine (HepB)

Adjuvant-containing influenza vaccine inactivated (Fluad): Safety and efficacy of concomitant or sequential administration with adjuvant-containing hepatitis B vaccine recombinant (Heplisav-B) not studied100

Non-adjuvant-containing influenza vaccine inactivated: May be given concurrently with any HepB vaccine using separate syringes and different injection sites100

Adjuvant-containing influenza vaccine inactivated (Fluad): Consider not using concomitantly with adjuvant-containing HepB vaccine recombinant (Heplisav-B);100 do not delay influenza vaccination if a non-adjuvant-containing influenza vaccine inactivated is not available100

Immune globulin (immune globulin IM [IGIM], immune globulin IV [IGIV], immune globulin subcutaneous) or specific hyperimmune globulin (hepatitis B immune globulin [HBIG], rabies immune globulin [RIG], tetanus immune globulin [TIG], varicella zoster immune globulin [VZIG])

No evidence that immune globulin preparations interfere with immune response to inactivated vaccines134

Influenza vaccine inactivated may be given concurrently with or at any interval before or after immune globulin or specific hyperimmune globulin134

Immunosuppressive agents (e.g., alkylating agents, antimetabolites, certain biologic response modifiers, corticosteroids, cytotoxic drugs, radiation)

Potential for decreased immune responses to vaccines105 134 190

Anti-B-cell antibodies (e.g., rituximab): Optimal time to administer vaccines after such treatment unclear135

Corticosteroids: May reduce immune responses to vaccines if given in greater than physiologic doses134

Chemotherapy or radiation: Give inactivated vaccines ≥2 weeks before or defer until ≥3 months after such therapy if possible;134 135 if indicated based on the time of the year, IDSA states influenza vaccine inactivated can be given during or <3 months after chemotherapy discontinued135

Anti-B-cell antibodies (e.g., rituximab): Give inactivated vaccines ≥2 weeks before or defer until ≥6 months after such treatment105 134 135

Certain biologic response modifiers (e.g., colony-stimulating factors, interleukins, tumor necrosis factor [TNF] blocking agents): Give inactivated vaccines ≥2 weeks prior to initiation of such therapy;105 134 if inactivated vaccine indicated in patient with chronic inflammatory illness receiving maintenance therapy with a biologic response modifier, some experts state do not withhold the vaccine because of concern about exacerbation of inflammatory illness105 135

Corticosteroids: Some experts state give inactivated vaccines ≥2 weeks prior to initiation of immunosuppressive corticosteroid therapy if feasible,105 134 but may be given to those receiving long-term corticosteroid therapy for inflammatory or autoimmune disease;105 IDSA states, although it may be reasonable to delay inactivated vaccines in patients treated with high-dose corticosteroid therapy, recommendations for use of influenza vaccine inactivated in individuals receiving corticosteroid therapy (including high-dose corticosteroid therapy) generally are the same as those for other individuals135

Phenytoin

Possible pharmacokinetic interaction (both increased and decreased serum concentrations of phenytoin reported)185 197 198

Pneumococcal vaccine

PCV13 (Prevnar 13): Concurrent administration with inactivated influenza vaccine in adults ≥50 years of age did not increase frequency of local adverse effects, but increased frequency of some solicited systemic reactions reported compared with administration of either vaccine alone181

PPSV23 (Pneumovax 23): Concurrent administration with inactivated influenza vaccine resulted in increased incidence of adverse local and systemic effects compared with administration of influenza vaccine alone;146 246 ACIP states concomitant administration results in satisfactory antibody responses without increasing incidence or severity of adverse reactions134

PCV13 (Prevnar 13): May be given concurrently with influenza vaccine inactivated using separate syringes and different injection sites105 112

PPSV23 (Pneumovax 23): May be administered concurrently with influenza vaccine inactivated using separate syringes and different injection sites100 134 352 353

Rotavirus vaccine (RV)

Concomitant use not studied167

May be given concurrently with or at any interval before or after influenza vaccine inactivated167

Theophylline

No clinically important interactions178 211 212

Influenza vaccine inactivated may be given to patients receiving aminophylline134

Zoster vaccine live (ZOS)

Concurrent administration of parenteral inactivated influenza vaccine and zoster vaccine live in adults ≥50 years of age results in antibody responses and adverse effects similar to those reported when the vaccines are administered 4 weeks apart119 490

May be given concurrently (using separate syringes and different injection sites) or at any interval before or after zoster vaccine481

Zoster vaccine recombinant (RZV)

Non-adjuvant-containing influenza vaccine inactivated: Concurrent administration with zoster vaccine recombinant in adults ≥50 years of age does not affect immune response to either vaccine106 117 and not associated with any safety concerns117

Adjuvant-containing influenza vaccine inactivated (Fluad): Safety and efficacy of concomitant or sequential administration with zoster vaccine recombinant not studied100 117

Non-adjuvant-containing influenza vaccine inactivated: May be given concurrently with zoster vaccine recombinant using separate syringes and different injection sites100

Adjuvant-containing influenza vaccine inactivated (Fluad): Consider not using concomitantly with zoster vaccine recombinant;100 do not delay influenza vaccination if a non-adjuvant-containing influenza vaccine inactivated not available100

Stability

Storage

Parenteral

Injectable Suspension, for IM Use

2–8°C; do not freeze.104 106 107 108 160 170 186 190 If freezing occurs, discard vaccine.104 106 107 108 160 170 186

Return multiple-dose vials to 2–8ºC between uses.104 108 Manufacturer of Afluria states discard any vaccine remaining in multiple-dose vial after a total of 20 doses have been removed from the vial and discard multiple-dose vial if not used within 28 days after vial first entered.108

Protect from light.106 108 170 186 190

Single-dose syringes and single-dose vials are preservative-free.104 106 107 108 160 170 186 190 Multiple-dose vials contain thimerosal as a preservative.104 108 190 (See Thimerosal Precautions under Cautions.)

Actions

  • Inactivated influenza vaccines are noninfectious, sterile suspensions of suitably inactivated influenza virus types A and B subunits.104 106 107 108 190

  • Most seasonal inactivated influenza vaccines commercially available in the US are split-virus preparations (i.e., contain purified subvirion or purified surface antigen) prepared from formaldehyde- or propiolactone-inactivated influenza viruses harvested from allantoic fluids of chick embryos (egg-based inactivated vaccines).100 104 106 107 108 An egg-based inactivated influenza vaccine that contains an adjuvant (i.e., MF59C.1) to increase antibody response also is available in the US.100 170 569 In addition an inactivated influenza vaccine prepared from propiolactone-inactivated influenza virus propagated in Madin Darby Canine Kidney (MDCK) cells (cell culture-based inactivated vaccine) is available in the US.100 190

  • Seasonal influenza vaccines are formulated annually to contain antigens representative of the strains of influenza A (H1N1), influenza A (H3N2), and influenza B viruses likely to circulate in the US during the upcoming influenza season.100 578

  • Trivalent inactivated influenza vaccines (egg-based) are available containing 2 influenza type A antigens (H1N1 and H3N2) and a single influenza type B antigen (B/Victoria lineage).100 160 170 190 575 In addition, quadrivalent inactivated influenza vaccines (egg- or cell culture-based) are available containing 2 influenza type A antigens (H1N1 and H3N2) and 2 influenza type B antigens (B/Yamagata and B/Victoria lineages).100 104 106 107 575 Quadrivalent formulations offer broader protection against circulating influenza B since they contain antigens representing both the B/Yamagata and B/Victoria lineages;100 112 influenza B viruses of both lineages have cocirculated since the 1980s.100 112

  • Influenza vaccines for the 2020–2021 influenza season contain the same influenza B (B/Victoria lineage) and influenza B (B/Yamagata lineage) antigens, but different influenza A (H1N1) and influenza A (H3N2) antigens, compared with those contained in vaccines used for the 2019–2020 influenza season.578

  • Influenza vaccines stimulate active immunity to influenza virus strains represented in the vaccines.100

  • Efficacy of influenza vaccines in preventing seasonal influenza virus infection depends on whether the virus strains represented in the vaccines are antigenically similar to influenza virus strains circulating during the influenza season.100 166 (See Limitations of Vaccine Effectiveness under Cautions.) When there is a good match between the vaccine formulation and circulating strains, a protective effect generally is achieved in 70–90% of healthy adults <65 years of age following IM administration of inactivated vaccine.165 235 480

  • Immune response to seasonal influenza vaccine inactivated may be lower in geriatric individuals,100 235 very young children,295 302 326 or individuals who are immunocompromised or have certain chronic medical conditions.100 105 235 248 261 290 310 377

  • In adults ≥65 years of age, standard-dose, adjuvant-containing trivalent inactivated influenza vaccine (Fluad) was noninferior to standard-dose, non-adjuvant-containing trivalent inactivated influenza vaccine based on antibody response and seroconversion rates.100 170 Immunogenicity of a single dose of standard-dose adjuvant-containing quadrivalent inactivated influenza vaccine (Fluad) was demonstrated in geriatric adults ≥65 years of age.186

  • In adults ≥65 years of age, high-dose trivalent inactivated influenza vaccine (Fluzone High-Dose; no longer available in US) was superior to standard-dose Fluzone (trivalent) for prevention of laboratory-confirmed influenza.160 Fluzone High-Dose (quadrivalent) is as immunogenic as Fluzone High-Dose (trivalent).160

Advice to Patients

  • Prior to administration of seasonal influenza vaccine inactivated, provide a copy of the appropriate CDC Vaccine Information Statement (VIS) to the patient or patient’s legal representative (VISs are available at [Web]).104 106 107 108 160 170 190 477

  • Advise patient and/or patient’s parent or guardian of the risks and benefits of vaccine administration.104 106 107 108 160 170 190

  • Advise patients that influenza vaccine inactivated contains noninfectious killed viruses and cannot cause influenza.100 104 106 107 108 160 170 190

  • Advise patients that influenza vaccine inactivated provides protection against illness due to influenza viruses represented in the vaccine and cannot provide protection against all respiratory illness.104 106 107 108 160 170 190 (See Limitations of Vaccine Effectiveness under Cautions.)

  • Advise patient and/or patient’s parent or guardian that annual vaccination against seasonal influenza is necessary.104 106 107 108 160 170 190

  • Importance of receiving a 2020–2021 seasonal influenza vaccine, even if the individual received a 2019–2020 seasonal influenza vaccine.100 112

  • Advise patient and/or patient’s parent or guardian that a single dose of seasonal influenza vaccine is necessary each year in adults, adolescents, and children ≥9 years of age, but that 2 doses of seasonal influenza vaccine may be necessary in some infants and children 6 months through 8 years of age.100 112 (See Pediatric Patients under Dosage and Administration.)

  • Importance of informing clinicians of severe or unusual adverse effects.104 106 107 160 170 190 Clinicians or individuals can report any adverse reactions that occur following vaccination to the Vaccine Adverse Event Reporting System (VAERS) at 800-822-7967 or [Web].104 106 107 160 170 190

  • Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as concomitant illnesses (e.g., GBS).104 106 107 160 170 190

  • Importance of women informing clinician if they are or plan to become pregnant or plan to breast-feed.104 106 107 160 170 190

  • Importance of informing patients of other important precautionary information.104 106 107 160 170 190 (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Influenza Virus Vaccine Inactivated Quadrivalent (2020–2020)

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Parenteral

Injectable suspension, for IM use

7.5 mcg hemagglutinin each of A/Victoria/2454/2019 IVR-207 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), B/Victoria/705/2018 BVR-11 (B/Victoria lineage), and B/Phuket/3073/2013 BVR-1B (B/Yamagata lineage) per 0.25 mL

Afluria Quadrivalent

Seqirus

7.5 mcg hemagglutinin each of A/Guangdong-Maonan/SWL1536/2019 CNIC-1909 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), B/Washington/02/2019 (B/Victoria lineage), and B/Phuket/3073/2013 (B/Yamagata lineage) per 0.25 mL

Fluzone Quadrivalent

Sanofi Pasteur

15 mcg hemagglutinin each of A/Victoria/2454/2019 IVR-207 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), B/Victoria/705/2018 BVR-11 (B/Victoria lineage), and B/Phuket/3073/2013 BVR-1B (B/Yamagata lineage) per 0.5 mL

Afluria Quadrivalent

Seqirus

15 mcg hemagglutinin each of A/Guangdong-Maonan/SWL1536/2019 CNIC-1909 (H1N1), A/Hong Kong/2671/2019 NIB-121 (H3N2), B/Washington/02/2019 (B/Victoria lineage), and B/Phuket/3073/2013 (B/Yamagata lineage) per 0.5 mL

Fluarix Quadrivalent

GlaxoSmithKline

15 mcg hemagglutinin each of A/Nebraska/14/2019 (H1N1), A/Delaware/39/2019 (H3N2), B/Darwin/7/2019 (B/Victoria lineage), and B/Singapore/INFTT-16-0610/2016 (B/Yamagata lineage) per 0.5 mL

Flucelvax Quadrivalent

Seqirus

15 mcg hemagglutinin each of A/Guangdong-Maonan/SWL1536/2019 CNIC-1909 (H1N1), A/Hong Kong/2671/2019 (H3N2), B/Washington/02/2019 NIB-121 (B/Victoria lineage), and B/Phuket/3073/2013 (B/Yamagata lineage) per 0.5 mL

Flulaval Quadrivalent

GlaxoSmithKline

15 mcg hemagglutinin each of A/Guangdong-Maonan/SWL1536/2019 CNIC-1909 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), B/Washington/02/2019 (B/Victoria lineage), and B/Phuket/3073/2013 (B/Yamagata lineage) per 0.5 mL

Fluzone Quadrivalent

Sanofi Pasteur

60 mcg hemagglutinin each of A/Guangdong-Maonan/SWL1536/2019 CNIC-1909 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), B/Washington/02/2019 (B/Victoria lineage), and B/Phuket/3073/2013 (B/Yamagata lineage) per 0.7 mL

Fluzone High-Dose Quadrivalent

Sanofi Pasteur

Influenza Virus Vaccine Inactivated Quadrivalent, Adjuvant-containing (2020–2021)

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Parenteral

Injectable emulsion, for IM use

15 mcg hemagglutinin each of A/Victoria/2454/2019 IVR-207 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), B/Victoria/705/2018 BVR-11 (B/Victoria lineage), and B/Phuket/3073/2013 BVR-1B (B/Yamagata lineage) per 0.5 mL

Fluad Quadrivalent

Seqirus

Influenza Virus Vaccine Inactivated Trivalent, Adjuvant-containing (2019–2020)

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Parenteral

Injectable emulsion, for IM use

15 mcg hemagglutinin each of A/Victoria/2454/2019 IVR-207 (H1N1), A/Hong Kong/2671/2019 IVR-208 (H3N2), and B/Victoria/705/2018 BVR-11 (B/Victoria lineage) per 0.5 mL

Fluad

Seqirus

AHFS DI Essentials™. © Copyright 2021, Selected Revisions September 7, 2020. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

References

Only references cited for selected revisions after 1984 are available electronically.

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107. GlaxoSmithKline. Flulaval Quadrivalent (influenza vaccine inactivated) suspension for intramuscular injection prescribing information. Research Triangle Park, NC; 2020 Jul.

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140. Aberer W. Vaccination despite thimerosal sensitivity. Contact Dermatitis. 1991; 24:6-10. http://www.ncbi.nlm.nih.gov/pubmed/2044374?dopt=AbstractPlus

141. Williams WW, Hickson MA, Kane MA et al. Immunization policies and vaccine coverage among adults: the risk for missed opportunities. Ann Intern Med. 1988; 108:616-25. http://www.ncbi.nlm.nih.gov/pubmed/2964806?dopt=AbstractPlus

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