Questions & Answers
Smallpox - Vaccine Description
Back to Parent Q&A Category Back to All Smallpox Q&A Back to All Q&A Back to Smallpox


  1. Is ACAM2000 an effective vaccine?
    Based on historical evidence, vaccinated individuals are considered protected against smallpox after a major cutaneous reaction is observed following primary vaccination. From a clinical perspective, ACAM2000 elicited a strong immune response in all study populations. ACAM2000 induced positive cutaneous responses in >96% of vaccinia-naïve subjects and in >84% of previously vaccinated subjects in pre-licensure studies.

  2. Who is the manufacturer of ACAM2000?

    Peterhouse Technology Park
    100 Fulbourn Road
    Cambridge CB1 9PT, UK

  3. What are Acambis's responsibilities to CDC and DoD?
    Acambis developed ACAM2000 under contracts with the US Centers for Disease Control and Prevention (CDC) as part of its preparations for a public health emergency. ACAM2000 is the primary smallpox vaccine for use in an emergency and forms the majority of the US Government's smallpox vaccine Strategic National Stockpile (SNS). Acambis is currently in negotiations with the CDC to provide the US Government with a long-term ACAM2000 production capability that is located entirely in the US.

  4. How will it be supplied?

    ACAM2000, Smallpox (Vaccinia) Vaccine, Live is supplied in multiple-dose 3 mL clear glass vials containing lyophilized powder (freeze-dried vaccine). After reconstitution with 0.3 mL of diluent, the vial contains approximately 100 nominal doses of 0.0025 mL of vaccinia virus (live,) 1.0 - 5.0x108 PFU/mL or 2.5-12.5x105 PFU/dose.

    Diluent for ACAM2000 is supplied in 3 mL clear glass vials containing 0.6 mL of diluent.

    Bifurcated needles are supplied in boxes (5 x 5 x 1 in) containing 100 needles.

    1 mL tuberculin syringes with 25 gauge x 5/8" needles are supplied for vaccine reconstitution.

  5. How is ACAM2000 stored and handled?

    Prior to reconstitution, ACAM2000 vaccine retains a potency of 1.0x108 PFU or higher per dose for at least 18 months when stored at refrigerated temperatures of 2-8°C (36-46°F).

    After reconstitution, ACAM2000 vaccine may be administered during a 6 to 8 hour workday at room temperature (20-25°C, 68-77°F). Do not expose ACAM2000 to room temperature conditions for more than 48 hours. Reconstituted ACAM2000 vaccine may be stored in a refrigerator (2-8°C, 36-46°F) no longer than 30 days, after which it should be discarded.

    Diluent for Smallpox Vaccine, (Vero Cells) Lyophilized, ACAM2000 should be stored in a refrigerator (2-8°C, 36-46°F). ACAM2000 contains live vaccinia virus that is transmissible, and should be handled as an infectious agent once vials are opened.

  6. Do vaccinees need signed consent to receive this vaccine?
    No, since it is FDA approved, there is no requirement for signed consent.

  7. Is there a change in the process to administer ACAM2000?
    Yes, all personnel (primary vaccinees and re-vaccinees) who receive ACAM2000 will receive 15 jabs with a bifurcated needle.

  8. If a vaccinee has a question about ACAM2000, what DoD resources are available to them?
    Immunization Healthcare Branch:
    DoD Vaccine Clinical Call Center:
    • Toll Free: 1-877-GET-VACC or (877) 438-8222

  9. Do those vaccinated with Dryvax need to be revaccinated with ACAM2000 sooner than 10 years?
    No. Personnel previously vaccinated with Dryvax have an increased level of protection against smallpox and should only be re-vaccinated IAW DoD policy. Most people will require re-vaccination after 10 years.

  10. What education information will a vaccinee receive?
    Anyone vaccinated with the smallpox vaccine will receive a DoD Smallpox Information Brochure, a Medication Guide, and additional information as requested.

  11. Is this smallpox vaccine diluted?
    The smallpox vaccine is stored as a powder and then a diluent (liquid) is added to reconstitute the powder shortly before use. The reconstituted vaccine is the same as the original full-strength concentration.

  12. Is smallpox vaccine live or synthetic?
    Smallpox vaccine is "live". It contains natural, live vaccinia viruses.

  13. How is smallpox vaccine given?
    The smallpox vaccine is not given with a typical needle. It is not a "shot" like many vaccinations. The vaccine is given using a bifurcated (two-pronged) needle that is dipped into the vaccine solution. A bifurcated needle looks like a little pitchfork or tuning fork. When dipped into the vaccine vial, the needle retains a droplet of the vaccine between the two prongs. The needle is then used to prick the skin 15 times in a few seconds. The pricking is not deep, but it will cause a sore spot and a very small drop of blood to form. The vaccine usually is given on the upper arm.

  14. Who will administer smallpox vaccine?
    Trained healthcare workers will administer the vaccine. Typically this would be a nurse or a medic.