ACAM2000 Dosage

Route of Administration

Administer ACAM2000 only after being trained on the safe and effective administration of the vaccine by the percutaneous route (scarification).

Do not administer ACAM2000 by injection.

Vaccine Preparation

ACAM2000 is supplied as a multiple dose vial of Lyophilized Antigen Component, Live to be reconstituted with the supplied Diluent Component.

The Lyophilized Antigen Component, Live is supplied in cartons and vials labeled “Smallpox (Vaccinia) Vaccine, Live, ACAM2000.” The Diluent Component may be supplied in cartons and vials labeled “Diluent for Smallpox (Vaccinia) Vaccine, Live, ACAM2000.” Reconstitution instructions and storage following reconstitution are described below.

Reconstitution

Reconstitute the Lyophilized Antigen Component, Live only with 0.3 mL of the provided Diluent Component to form ACAM2000. Note: 0.3 mL of diluent is not the entire content of the vial of Diluent Component.

Remove the Lyophilized Antigen Component, Live vial from freezer or refrigerator and bring to room temperature before reconstitution.

Remove the flip cap seals of the Lyophilized Antigen Component, Live and Diluent Component vials and wipe with an isopropyl alcohol swab and allow to dry thoroughly.

Use aseptic technique and a sterile 1 mL syringe fitted with a 25 gauge x 5/8” needle (provided) to draw up 0.3 mL from the Diluent Component vial and transfer the entire content of the syringe to the Lyophilized Antigen Component, Live vial.

Gently swirl to mix, do not shake or invert the vial, and avoid product contact with the rubber stopper.

The reconstituted vaccine should be a clear to slightly hazy, colorless to straw-colored liquid free from extraneous matter. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. If particulate matter or discoloration is observed, do not use the vaccine and dispose of the vial as biohazardous material.

After reconstitution, each vial contains 100 nominal doses of approximately 0.0025 mL each.

Storage following Reconstitution

After reconstitution, ACAM2000 may be administered within 8 hours if kept at 20°C to 25°C (68°F to 77°F). Store unused, reconstituted ACAM2000 in a refrigerator 2°C to 8°C (36°F to 46°F) for up to 30 days, after which the unused portion is to be discarded as a biohazardous material. Minimize exposure of reconstituted vaccine to room temperature during vaccination sessions by placing it in the refrigerator or on ice between patient administrations.

Preparation / Handling Precautions

Wear surgical or protective gloves when preparing and administering the vaccine to avoid contact of vaccine with skin, eyes or mucous membranes.

Vaccine Administration

Bring the reconstituted vaccine to room temperature prior to administration. Before administration, examine the vial contents to verify the absence of particulates and gently swirl, without allowing the product to contact the rubber stopper, if necessary to re-dissolve any precipitates that might have formed.

The site of vaccination is the upper arm over the insertion of the deltoid muscle.

No skin preparation should be performed unless the skin at the intended site of vaccination is obviously dirty, in which case an alcohol swab(s) may be used to clean the area. If alcohol is used, the skin must be allowed to dry thoroughly to prevent inactivation of the live vaccine virus by the alcohol.

Remove the vaccine vial cap. Remove bifurcated needle from individual wrapping. Submerge bifurcated end of needle in reconstituted vaccine solution. The needle will pick up a droplet of vaccine (approximately 0.0025 mL) within the fork of the bifurcation. Use aseptic technique, i.e., do not insert the upper part of the needle that has been in contact with fingers into the vaccine vial, and never redip the needle into the vaccine vial if the needle has touched skin.

Deposit the droplet of vaccine onto clean, dry skin of the arm prepared for vaccination. The needle is held between thumb and first finger perpendicular to the skin. The wrist of the vaccinator’s hand holding the needle rests against the vaccine recipient’s arm. Rapidly make 15 jabs of the needle perpendicular to the skin through the vaccine droplet to puncture the skin, within a diameter of about 5 mm. The jabs should be vigorous enough so that a drop of blood appears at the vaccination site.

Wipe any excess droplets of vaccine and blood off the skin using a dry gauze pad and discard in a biohazard container. Discard the needle in a biohazard sharps container. Close the vaccine vial by reinserting the rubber cap and return to a refrigerator or place on ice unless it will be used immediately to vaccinate another individual.

Disposal

Discard the Lyophilized Antigen Component, Live vial (including any unused reconstituted vaccine), its stopper, the syringe and needle used for reconstitution, the bifurcated needle used for administration, and any gauze or cotton that came in contact with the vaccine in leak-proof, puncture-proof biohazard containers. Dispose of these containers appropriately.

Care of the Vaccination Site

Ensure each vaccine recipient has the FDA-approved Medication Guide, which includes instructions for care of the vaccination site.

Cover vaccination site with gauze and secure it loosely with first aid adhesive tape. The gauze provides a barrier to protect against spread of the vaccinia virus. If the vaccinee is involved in direct patient care, the gauze may be covered with a semipermeable (semi-occlusive) dressing as an additional barrier. A semipermeable dressing is one that allows for the passage of air but does not allow for the passage of fluids.

Do not use a bandage that blocks air from the vaccination site. This may cause the skin at the vaccination site to soften and wear away.

Wash hands with soap and warm water or with alcohol-based hand rubs such as gels or foams after direct contact with the vaccination site, the gauze and semipermeable dressing, clothes, towels or sheets that might be contaminated with virus from the vaccination site. This is vital in order to remove any virus from your hands and prevent contact spread.

Throw away the contaminated gauze and semipermeable dressing in a sealed plastic bag. A small amount of bleach can be added to the bag to kill the vaccine virus.

Wash separately clothing, towels, bedding or other items that may have come in direct contact with the vaccination site or drainage from the site, using hot water with detergent and/or bleach. Wash hands afterwards.

Do not put salves or ointments on the vaccination site.

Interpreting Vaccination Response

Primary Vaccinees

In an individual vaccinated for the first time (primary vaccination; vaccinia-naïve), the expected response to vaccination is the development of a major cutaneous reaction (characterized by a pustule) at the site of inoculation. The lesion evolves gradually, with appearance of a papule at the site of vaccination after 2-5 days. The papule becomes vesicular surrounded by a red areola, then pustular, and reaches its maximum size at 8-10 days after vaccination; the pustule dries and forms a scab (See Figure 1). In primary vaccinees, scab separation and re-epithelialization occurs 3-6 weeks after vaccination, leaving a pitted scar. Formation of a major cutaneous reaction by day 6-11 is evidence of a successful ‘take’ and acquisition of protective immunity. An equivocal reaction is any reaction that is not a major reaction and indicates a non-take (vaccination failure) due to impotent vaccine or inadequate vaccination technique.

Individuals who are not successfully vaccinated (i.e., vaccination failures) after primary vaccination may be revaccinated again in an attempt to achieve a satisfactory take. The vaccination procedures should be checked, and vaccination repeated with vaccine from another vial or vaccine lot, employing the same technique described in section 2.4. If a repeat vaccination is conducted using vaccine from another vial or vaccine lot fails to produce a major reaction, healthcare providers should consult the Centers for Disease Control and Prevention (CDC) Emergency Operations Center (EOC) at 770-488-7100 and their state or local health department before giving another vaccination.

Previously Vaccinated Individuals (Revaccination)

Based on data from Study 2, successful vaccination in an individual previously exposed to vaccine (vaccinia-experienced) is confirmed when a major cutaneous reaction is observed 6 to 8 days post-vaccination. A major cutaneous reaction at the vaccination site heals through the same stages as described in primary vaccinees and scab separation may occur earlier in revaccinated individuals than in primary vaccinees (Figure 2). However, any prior vaccination may modify (reduce) the cutaneous response upon revaccination (Figure 2) such that the absence of a cutaneous response does not necessarily indicate vaccination failure. Vaccinia-experienced individuals who do not have a cutaneous response on revaccination do not require revaccination to try to elicit a cutaneous response.

Figure 1 Progression of Major Cutaneous Reaction After Primary Vaccination (1)

Figure 2 Progression of Major Cutaneous Reaction After Revaccination (1)

Revaccination

The U.S. Centers for Disease Control and Prevention (CDC) has recommendations for revaccination of laboratory and health care personnel at risk for occupational exposure to variola and mpox viruses (2).