mNEXSPIKE

Pronunciation: em-nex'-spyk
Generic name: COVID-19 Vaccine, mRNA
Dosage form: suspension for intramuscular injection (0.2 mL)
Drug class: Viral vaccines

Medically reviewed by Carmen Pope, BPharm. Last updated on Sep 19, 2025.

What is mNEXSPIKE? COVID-19 Vaccine

mNEXSPIKE is a COVID-19 vaccine containing messenger RNA (mRNA) technology designed to protect against COVID-19 infection. The 2025-2026 lower dose formula represents the latest updated version of Moderna's mRNA COVID-19 vaccine, specifically targeting the currently circulating LP.8.1 variants of SARS-CoV-2.

mNEXSPIKE cannot cause COVID-19 because it does not contain the SARS-CoV-2 virus. Instead, it uses mRNA technology to instruct cells to produce a protein that triggers immune protection against COVID-19.

Key Facts About mNEXSPIKE

• Generic name: COVID-19 Vaccine, mRNA (2025-2026 Formula)
• Brand name: mNEXSPIKE
• Drug class: Vaccines
• Mechanism of Action: mRNA technology
• FDA Approval: 30 May 2025
• Manufacturer: Moderna US, Inc.

mNEXSPIKE Uses

mNEXSPIKE is FDA-approved for COVID-19 prevention in the following specific populations:

• Adults 65 years and older
• All adults and adolescents 12-64 years with high-risk factors for severe COVID-19.

High-Risk Conditions Include:

• Chronic respiratory diseases (asthma, COPD)
• Heart disease and cardiovascular conditions
• Diabetes (Type 1 and Type 2)
• Chronic kidney disease
• Chronic liver disease
• Immunocompromised conditions
• Obesity (BMI ≥30)
• Cancer or history of cancer
• Neurologic conditions
• Pregnancy.

Note: In the U.S., some states may have differing rules on vaccinations, particularly if you live in the West. If you are unsure of your vaccination eligibility, check with your local healthcare provider or pharmacist.

Important: mNEXSPIKE may not protect all people who receive the vaccine. Breakthrough infections can still occur, but vaccination significantly reduces the risk of severe COVID-19, hospitalization, and death.

Update: ACIP Meeting September 19, 2025:

Key COVID-19 vaccination decisions made, awaiting CDC director approval (typically accepted).

• No Prescription Required: The ACIP voted 6-6 against requiring prescriptions for COVID-19 vaccines, with the chair casting a dissenting vote. Members argued that prescriptions create barriers for underinsured populations at the highest risk.
• Updated Recommendations: Unanimous approval for individual decision-making approach. Adults 65 and older, as well as individuals aged 6 months to 64 years, use shared clinical decision-making, emphasizing a higher benefit for those with increased severe COVID-19 risk factors.

How mNEXSPIKE Works

mNEXSPIKE uses messenger RNA (mRNA) technology to provide COVID-19 protection:

• mRNA delivery: The vaccine delivers genetic instructions to cells
• Protein production: Cells use mRNA to produce the SARS-CoV-2 spike protein
• Immune response: The immune system recognizes the spike protein as foreign
• Antibody production: B-cells produce antibodies against the spike protein
• Memory formation: Immune memory cells remember how to fight COVID-19.

This process trains your immune system to recognize and fight SARS-CoV-2 if exposed to the actual virus in the future.

mNEXSPIKE Side Effects

Common Side Effects (Very Common):

Injection site reactions:

• Pain at the injection site
• Tenderness and swelling
• Swollen lymph nodes in the same arm
• Redness and hardness at the injection site

Systemic reactions:

• Fatigue and tiredness
• Headache
• Muscle pain (myalgia)
• Joint pain (arthralgia)
• Chills
• Nausea and vomiting
• Fever.

These side effects are typically mild to moderate and resolve within 1-3 days.

Serious Side Effects (Rare)

Severe Allergic Reactions (Anaphylaxis)

There is a very small risk that mNEXSPIKE could cause a severe allergic reaction. For this reason, your healthcare provider may ask you to stay for a short time at the place where you received your vaccine. Seek emergency medical attention immediately if you experience:

• Difficulty breathing or shortness of breath
• Swelling of the face, lips, tongue, or throat
• Rapid heartbeat or palpitations
• Widespread skin rash or hives
• Severe dizziness or fainting
• Weakness or feeling faint

Timeline: Usually occurs within minutes to 1 hour after vaccination.

Heart Inflammation (Myocarditis/Pericarditis)

Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining outside the heart) have occurred in some people who have received mRNA COVID-19 vaccines.  

Risk factors:

• Highest risk: Males aged 12-24 years (approximately 27 cases per million doses)
• General population: Ages 6 months to 64 years (approximately 8 cases per million doses)
• Timing: Symptoms typically begin within 1 week of vaccination.

Warning signs to watch for (especially first 2 weeks):

• Chest pain or pressure
• Shortness of breath or difficulty breathing
• Feelings of a fast-beating, fluttering, or pounding heart
• Unusual fatigue.

Prognosis: Most cases resolve with anti-inflammatory treatment, though some people may have persistent heart changes on MRI scans. Long-term effects are still being studied.

Report vaccine side effects to VAERS (Vaccine Adverse Event Reporting System), phone 1-800-822-7967, vaers.hhs.gov, or your healthcare provider. Reporting helps monitor vaccine safety and identify rare side effects.

Related/similar drugs

Before Receiving mNEXSPIKE

Absolute Contraindications

Do NOT receive mNEXSPIKE if you have:

• Severe allergy to any previous dose of mNEXSPIKE, SPIKEVAX, or any Moderna COVID-19 vaccine
• Severe allergy to any vaccine ingredient (see ingredients list below)
• Moderate to severe illness or infection. Wait until recovery before vaccination.

Tell your healthcare provider if you have:

• Any allergies or history of severe allergic reactions
• Previous COVID-19 vaccine reactions
• Heart problems - history of myocarditis or pericarditis
• Current illness or fever
• Bleeding disorders or are taking blood-thinning medications
• Immune system problems or are taking immunosuppressive medications
• Pregnancy or planning pregnancy
• Breastfeeding
• History of fainting with injections.

Pregnancy and Breastfeeding Considerations

COVID-19 vaccination is recommended during pregnancy because:

• COVID-19 poses serious risks to pregnant individuals
• mRNA vaccines have shown good safety profiles in pregnancy
• Vaccination may provide protection to newborns through maternal antibodies

Discuss with your healthcare provider to make an informed decision based on your individual circumstances.

mNEXSPIKE is recommended for breastfeeding individuals, and no safety concerns have been identified with mRNA vaccines during breastfeeding. There is also the potential benefit that antibodies may pass through breast milk to protect infants.

How is mNEXSPIKE Administered?

mNEXSPIKE is given as a single injection (one dose) into the upper arm muscle (deltoid).

Administration Guidelines:

Administered by trained healthcare professionals

Observation period - 15-30 minutes after injection to monitor for allergic reactions

Documentation - vaccination record should be updated

Spacing - follow CDC guidelines for spacing from other vaccines

Dosing Information

• Volume: 0.2 mL per dose
• Route: Intramuscular injection only
• Timing: Wait at least 3 months after the last dose of the COVID-19 vaccine. If you have recently had a COVID-19 infection, talk to your healthcare provider about how long you need to delay vaccination (some experts recommend waiting at least 3 months after a COVID-19 infection). 

What other drugs may affect mNEXSPIKE?

Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

• Immunosuppressive medications may reduce vaccine effectiveness
• Blood thinners may increase the risk of bruising at the injection site
• Other vaccines can be given simultaneously, but in different arms.

See the product information for a full list of interactions.

mNEXSPIKE Ingredients

Active ingredient: Messenger RNA (mRNA) - encoding SARS-CoV-2 spike protein

Inactive ingredients: Lipids: SM-102, PEG 2000 DMG, cholesterol, DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine), tromethamine and tromethamine hydrochloride (pH adjusters), Sucrose (stabilizer).

mNEXSPIKE does NOT contain:

• Preservatives
• Live or inactivated SARS-CoV-2 virus
• Eggs, gelatin, latex, or gluten
• Antibiotics or metals.

Storage and Handling

mNEXSPIKE requires ultra-cold storage and careful handling:

• Frozen storage: -25°C to -15°C (-13°F to 5°F)
• Refrigerated storage: 2°C to 8°C (36°F to 46°F) for up to 30 days
• Room temperature: Up to 24 hours before administration

Protect from light during storage and transport

Healthcare facilities must follow strict cold chain protocols to maintain vaccine potency.

Frequently Asked Questions

What is the difference between mNEXSPIKE and Spikevax?

mNexspike is a next-generation COVID-19 vaccine that uses only one-fifth the dose of their current Spikevax vaccine. This lower dose is possible due to a more targeted design that creates a focused immune response.

How effective is mNEXSPIKE?

Clinical trials and real-world data show mRNA COVID-19 vaccines are highly effective at preventing severe COVID-19, hospitalization, and death, though breakthrough infections can occur with new variants.

Can I get mNEXSPIKE with other vaccines?

Yes, mNEXSPIKE can be given simultaneously with other vaccines (like flu vaccine), but should be administered in different arms.

How long does protection last?

Protection may wane over time, which is why updated formulas like the 2025-2026 version are developed to maintain effectiveness against circulating variants.

What if I've had COVID-19 before?

You should still receive mNEXSPIKE as vaccination provides broader and longer-lasting protection than natural infection alone.

Can immunocompromised people receive mNEXSPIKE?

Yes, but they should consult their healthcare provider, as they may need additional doses and may not mount as strong an immune response.

When to Seek Medical Care

Seek immediate emergency care for:

• Signs of severe allergic reaction (difficulty breathing, swelling, widespread rash)
• Severe chest pain or pressure
• Severe difficulty breathing
• Severe or persistent symptoms that concern you.

Contact your healthcare provider for:

• Mild chest discomfort or heart palpitations
• Side effects that worsen or don't improve after 3 days
• Any symptoms that concern you
• Questions about when to receive your next COVID-19 vaccine.

Manufacturer

Moderna US, Inc., Princeton, NJ 08540

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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