Dosing and uses of ACAM2000 (smallpox [vaccinia] vaccine, live)
Adult dosage forms and strengths
lyophilized powder for reconstitution
- Following reconstitution: 2.5-12.5 x 10^5 plaque forming units/0.0025mL
- Both the vaccine and provided diluent vial stoppers do not contain latex material
Smallpox Immunization
Indicated for active immunization against smallpox disease for persons determined to be at high risk for smallpox infection
A droplet is administered by the percutaneous route (scarification) using 15 jabs of a bifurcated needle (see Administration for complete preparation and scarification instructions)
Immunization Schedules
Up-to-date vaccination schedules available at https://www.cdc.gov/vaccines/schedules/hcp/index.htmL
Pediatric dosage forms and strengths
lyophilized powder for reconstitution
- Following reconstitution: 2.5-12.5 x 10^5 plaque forming units/0.0025mL
- Both the vaccine and provided diluent vial stoppers do not contain latex material
Smallpox Immunization
<16 years: Safety and efficacy not established; use of the vaccine in all pediatric age groups is supported by evidence from the adequate and well-controlled studies in adults and with additional historical data with use of live vaccinia virus smallpox vaccine in pediatrics
No longer recommended for routine immunization since smallpox disease has been eradicated
Indicated for active immunization against smallpox disease for persons determined to be at high risk for smallpox infection
A droplet is administered by the percutaneous route (scarification) using 15 jabs of a bifurcated needle (see Administration for complete preparation and scarification instructions)
Dosing Considerations
Before the eradication of smallpox disease, live vaccinia virus smallpox vaccine was administered routinely in all pediatric age groups, including neonates and infants, and was effective in preventing smallpox disease
During that time, live vaccinia virus was occasionally associated with serious complications in children, the highest risk being in infants aged ≤1 yr
ACAM2000 (smallpox [vaccinia] vaccine, live) adverse (side) effects
>10%
Injection site pruritus (82-92%)
Injection site erythema (61-74%)
Injection site pain (37-67%)
Blood and lymphatic system disorders (22-59%)
Lymph node pain (19-57%)
Headache (32-50%)
Injection site swelling (28-48%)
Fatigue (34-48%)
Myalgia (27-46%)
Malaise (28-37%)
Feeling hot (20-32%)
GI disorders (23-31%)
Erythema (22-24%)
Rigors (12-21%)
Nausea (10-19%)
Diarrhea (12-16%)
Decreased exercise tolerance (8-11%)
Rash (6-11%)
1-10%
Constipation (6%)
Vomiting (3-5%)
Dyspnea (3-4%)
Lymphadenopathy (6-8%)
Warnings
Black box warnings
Suspected cases of myocarditis and/or pericarditis have been observed in healthy adult primary vaccinees
Encephalitis, encephalomyelitis, encephalopathy, progressive vaccinia, generalized vaccinia, severe vaccinial skin infections, erythema multiforme major (including Stevens-Johnson syndrome), and eczema resulting in permanent sequelae or death, ocular complications, blindness, and fetal death have occurred following either primary vaccination or revaccination with smallpox vaccines
This is a live vaccinia virus that can be transmitted to persons who have close contact with the recipient of the vaccine, and the risks in contacts are the same as those for the vaccinated patient
The risk for experiencing serious vaccination complications must be weighed against the risks for experiencing a potentially fatal smallpox infection
Risks increased with the following conditions
- These risks of severe adverse effects are increased with the following conditions and may result in severe disability, permanent neurologic sequelae, and/or death
- Cardiac disease or a history of cardiac disease
- Eye disease treated with topical steroids
- Congenital or acquired immune deficiency disorders, including those taking immunosuppressive medications
- Eczema and persons with a history of eczema or other acute or chronic exfoliative skin conditions
- Infants aged <1 yr
- Pregnancy
Contraindications
There are very few absolute contraindications to the vaccine for those who are at high risk for smallpox
The risk for experiencing serious vaccination complications must be weighed against the risks for experiencing a potentially fatal smallpox infection; see Cautions for persons who are at higher risk of experiencing serious vaccination complications
Severe immune deficiency
- Severe localized or systemic infection with vaccinia (progressive vaccinia) may occur in persons with weakened immune systems
- Individuals with severe immunodeficiency who are not expected to benefit from the vaccine should not receive ACAM2000
- These individuals may include those who are undergoing bone marrow transplantation or individuals with primary or acquired immunodeficiency who require isolation
Cautions
Serious complications may follow vaccination and may include myocarditis and/or pericarditis, encephalitis, encephalomyelitis, encephalopathy, progressive vaccinia (vaccinia necrosum), generalized vaccinia, severe vaccinial skin infections, erythema multiforme major (including Stevens-Johnson syndrome), eczema vaccinatum, blindness, and fetal death in pregnant women; these complications may rarely lead to severe disability, permanent neurological sequelae, and death
Ischemic cardiac events and nonischemic, dilated cardiomyopathy have been reported following smallpox vaccination; relationship to the vaccine is unknown
Accidental infection of the eye (ocular vaccinia) may result in ocular keratitis, corneal scarring, and blindness
Severe localized or systemic infection with vaccinia (progressive vaccinia) may occur in persons with weakened immune systems, including those with leukemia, lymphoma, organ transplantation, generalized malignancy, HIV/AIDS, cellular or humoral immune deficiency, radiation therapy, or treatment with antimetabolites, alkylating agents, high-dose corticosteroids (>10 mg prednisone/day or equivalent for ≥2 weeks), or other immunomodulatory drugs; contraindicated in individuals with severe immunodeficiency (see Contraindications)
Persons with eczema of any description such as, atopic dermatitis, neurodermatitis, and other eczematous conditions, regardless of severity of the condition, or persons who have a history of these conditions at any time in the past, are at higher risk of developing eczema vaccinatum
Not studied in infants or children; risk of serious adverse events is higher in infants; vaccinated persons who have close contact with infants (eg, breastfeeding women), must take precautions to avoid inadvertent transmission of live vaccinia virus to infants
Not studied in pregnant women; live vaccinia virus vaccines can cause fetal vaccinia and fetal death; if administered during pregnancy, the vaccinee should be apprised of the potential hazard to the fetus; pregnant women who are close contacts of vaccinees may be at increased risk because live vaccinia virus can shed and be transmitted to close contacts
Contains neomycin and polymyxin B; caution with history of allergy to these components on
Vaccinia immune globulin (VIG) is indicated for certain complications of vaccination live vaccinia virus smallpox vaccine; if VIG is needed or additional information is required, physicians should contact the CDC at (404) 639-3670 (M-F) or (404) 639-2888 evenings/weekends
The most important measure to prevent inadvertent auto-inoculation and contact transmission from vaccinia vaccination is thorough hand washing after changing the bandage or after any other contact with the vaccination site
Avoid blood and organ donation for at least 30 days following vaccination
Pregnancy and lactation
Pregnancy
Pregnancy category: D; has not been studied in pregnant women
The only setting in which vaccination of pregnant women should be considered is when exposure to smallpox is considered likely
Live vaccinia virus vaccines can cause fetal harm when administered to a pregnant woman; congenital infection, principally occurring during the first trimester, has been observed after vaccination with live vaccinia smallpox vaccines, although the risk may be low
Generalized vaccinia of the fetus, early delivery of a stillborn infant, or a high risk of perinatal death has been reported
If this vaccine is used during pregnancy, or if the vaccinee lives in the same household with or has close contact with a pregnant women, the vaccinee should be apprised of the potential hazard to the fetus
Lactation
Not known if excreted in breast milk, not recommended for nursing women in non-emergency situations
Live vaccinia virus can be inadvertently transmitted from a lactating mother to her infant
Infants are at high risk of developing serious complications from live vaccinia smallpox vaccination
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of ACAM2000 (smallpox [vaccinia] vaccine, live)
Mechanism of action
Lyophilized preparation of live vaccinia virus; vaccinia virus is similar to the variola (smallpox) virus; immunity to both virus achieved with induced vaccinia virus infection by stimulating the production of neutralizing antibodies
Conveys active immunity via stimulation of production of endogenously produced antibodies
Pharmacokinetics
Onset: Neutralizing antibodies appear 15-20 days after vaccination; appearance of neutralizing antibodies may occur 7 days following vaccination
Administration
Vaccine Preparation
Reconstitution
- Reconstitute only with diluent provided
- Removed vial from cold storage and bring to room temperature before reconstitution
- Remove the flip cap seals of the vaccine and diluent vials and wipe each rubber stopper with an isopropyl alcohol swab and allowed to dry thoroughly
- Using aseptic technique and a sterile 1 mL syringe fitted with a 25 gauge x 5/8” needle (provided), draw up 0.3 mL of diluent and transfer the entire content of the syringe to the vaccine vial
- Note: this 0.3 mL of diluent is not the entire content of the diluent vial
- Gently swirl to mix but try not to get product on the rubber stopper
- Reconstituted liquid should appear clear to slightly hazy, colorless to straw-colored, and free from extraneous matter
- Inspect visually for particulate matter and discoloration prior to administration; if particulate matter or discoloration is observed, the vaccine should not be used and the vial should be disposed of according to biocontaminant regulations
Handling precautions and disposaL
- Personnel preparing and administering the vaccine should wear surgical or protective gloves and avoid contact of vaccine with skin, eyes or mucous membranes
- The vaccine vial, its stopper, the diluent syringe, the vented needle used for reconstitution, the bifurcated needle used for administration, and any gauze or cotton that came in contact with the vaccine should be discarded in leak-proof, puncture-proof biohazard containers
- These containers should then be disposed of appropriately
Percutaneous (Scarification) Administration
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; the skin must be allowed to dry thoroughly to prevent inactivation of the live vaccine virus by the alcohoL
Remove the vaccine vial cap and bifurcated needle from individual wrapping; submerge bifurcated end of needle in reconstituted vaccine solution; the needle will pick up a droplet of vaccine (0.0025 mL) within the fork of the bifurcation
Use aseptic technique; ie, 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 hand holding the needle of the vaccinator rests against the patient’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
Any excess droplets of vaccine and blood should be wiped off the skin using a dry gauze pad and discarded 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 subject (see Storage)
Cover the vaccination site loosely with a gauze bandage, using first aid adhesive tape to keep it in place; this bandage provides a barrier to protect against spread of the vaccinia virus
If the vaccinee is involved in direct patient care, the gauze should be covered with a semipermeable (semiocclusive) 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
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 bandage or 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
Put the contaminated bandages in a sealed plastic bag and throw them away in the trash
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
Don’t use a bandage that blocks air from the vaccination site; this may cause the skin at the vaccination site to soften and wear away; use loose gauze secured with medical tape to cover the site
Don’t put salves or ointments on the vaccination site
See ACAM2000 prescribing information for visual photos on how to interpret vaccination response
Storage
Lyophilized powder
- Store in freezer with an average temperature of -15°C to -25°C (+5°F to -13°F)
- Prior to reconstitution, smallpox vaccine retains a potency of ≥1 x 10^8 PFU per dose for at least 18 months when stored at refrigerated temperatures of +2-8°C (36-46°F)
- During shipment: Maintain temperature of -10°C or colder
Reconstituted solution
- After reconstitution, vaccine may be administered within 6-8 hr if kept at room temperature (20-25°C, 68-77°F)
- Unused, reconstituted vaccine may be refrigerated (2-8°C, 36-46°F) for up to 30 days, after which it should be discarded as a biohazardous material
- Exposure of reconstituted vaccine to room temperature during vaccination sessions should be minimized by placing it in refrigerator or on ice between patient administrations
