Questions and Answers
ACAM2000TM Smallpox (Vaccinia) Vaccine, Live
- What is FDA announcing?
- How does ACAM2000 work?
- What is smallpox disease?
- Hasn't smallpox been eradicated?
- Is ACAM2000 different than Dryvax, a vaccine used in the global eradication of smallpox?
- How effective is ACAM2000?
- Are there any possible side effects associated with the use of ACAM2000?
- Who should not be immunized with ACAM2000?
- How will ACAM2000 recipients be informed of its potential risks?
- Why is ACAM2000 approved with a Risk Minimization Action Plan (RiskMAP)?
- Will ACAM2000 be available to anyone who wants it?
- What is FDA announcing?
- How does ACAM2000 work?
- What is smallpox disease?
- Hasn't smallpox been eradicated?
- Is ACAM2000 different than Dryvax, a vaccine used in the global eradication of smallpox?
- How effective is ACAM2000?
- Are there any possible side effects associated with the use of ACAM2000?
- Who should not be immunized with ACAM2000?
- How will ACAM2000 recipients be informed of its potential risks?
- certain information is necessary to prevent serious adverse events
- patient decision-making should be informed by information about a known serious side effect with a product, or
- patient adherence to directions for the use of a product are essential to its effectiveness.
- Why is ACAM2000 approved with a Risk Minimization Action Plan (RiskMAP)?
- Education of ACAM2000 Recipients and Health Care Providers
- to achieve safe and effective administration of ACAM2000
- to convey to vaccinees information concerning the risks and benefits of the vaccine
- to minimize the risks of the virus contained in the vaccine, the vaccinia virus, from spreading to other parts of the body and to other people
- Adverse Event Reporting
- a reporting and collection system for the expedited reporting of adverse events associated with the use of ACAM2000 that complies with the reporting requirements for an approved Biologics License Application
- submission to FDA of certain serious adverse events within 15 days of notification to the manufacturer
- Risk Management Evaluation
- to evaluate the effectiveness of the overall risk management program in assuring that ACAM2000 is used safely and the education goals are being met.
- Will ACAM2000 be available to anyone who wants it?
FDA is announcing the licensure of a new vaccine, Smallpox (Vaccinia) Vaccine, Live, with the proprietary name ACAM2000, for active immunization against smallpox disease for persons determined to be at high risk for smallpox infection.
The vaccine is manufactured by Acambis Inc., which has stated its intent to provide the vaccine for Strategic National Stockpile use only.
The approval and availability of this second-generation smallpox vaccine enhances the emergency preparedness of the United States against the use of smallpox as a dangerous biological weapon.
The vaccine is made from a virus called vaccinia, which is a "pox"-type virus related to smallpox but causes milder disease. ACAM2000 cannot cause smallpox; it does not contain the smallpox virus, but rather the "live" vaccinia virus - not dead virus like many other vaccines. For this reason, attentively caring for the vaccination site is important to prevent the virus from spreading from the vaccination site to other parts of the body, or to other people.
ACAM2000 is administered differently than the typical "shot" associated with most vaccinations. A two-pronged stainless steel (or bifurcated) needle is dipped into the vaccine solution and the skin is pricked several times in the upper arm with a droplet of the vaccine. The virus begins growing at the injection site causing a localized infection or "pock" to form. A red, itchy sore spot at the site of the vaccination within 3-4 days is an indicator that the vaccination was successful; that is, there is "a take." A blister develops at the vaccination site and then dries up forming a scab that falls off in the third week, leaving a small scar. The vaccine stimulates a person's immune system to develop antibodies and cells in the blood and elsewhere that can then help the body fight off a real smallpox infection if exposure to smallpox ever occurs.
Smallpox is a serious, highly contagious and often fatal infectious disease caused by the variola virus that emerged in human populations thousands of years ago. A person infected with smallpox develops a rash characterized as raised pocks on the face and body. A person with smallpox has infectious saliva and close contact can spread the virus. The virus could also be spread through other body fluids and contaminated clothing or bed linen.
Following a global eradication campaign, which included vaccination, the World Health Organization certified the eradication of naturally occurring smallpox disease in 1980. Until now, Dryvax, manufactured by Wyeth Laboratories, Inc., was the only vaccine licensed by FDA. Routine vaccination of the American public was stopped in 1972 after the disease was eradicated from the United States. However, smallpox has the potential to be deliberately used as a weapon by terrorists. A large proportion of the population has no immunity and fatality rates could be higher than 25% if smallpox were to be released as a bioterrorist weapon.
Both vaccines are derived from the New York City Board of Health strain of vaccinia, but Dryvax was grown on the skin of calves and then essentially freeze-dried for storage. It was licensed by FDA in 1931 but is no longer manufactured and remaining supplies are limited. ACAM2000, a "second generation" smallpox vaccine, is derived from a clone of Dryvax, purified, and produced using modern cell culture technology.
A clinical study to demonstrate ACAM2000 is non-inferior to Dryvax was conducted in each of two populations: those who had never been vaccinated for smallpox (naive) and those who had previous vaccination. For the naive population, the percentage of scar formation at the vaccination skin site or "take rates" were similar to Dryvax vaccinees. For those previously vaccinated, the immune response generated was acceptable for ACAM2000.
Specifically, the clinical study was a multi-center, randomized, controlled study, comparing ACAM2000 to Dryvax. To compare the efficacy in persons who had never been previously vaccinated against smallpox (naive), 780 subjects received ACAM2000 and 257 subjects received Dryvax. The recipients included males and females between the ages of 18 and 30 years. In a study of people previously vaccinated against smallpox, 1,242 subjects received ACAM2000 and 405 subjects, including males and females from 31-84 years old, received Dryvax. The percentage of unvaccinated persons who developed a successful immunization reaction was similar to that of Dryvax. ACAM2000 also was found to be acceptable as a booster in those previously vaccinated for smallpox.
Yes, health complications can occur after receiving the vaccine, and the risk of experiencing serious side effects must be weighed against the risk of experiencing a potentially fatal smallpox infection.
The vaccine may cause myocarditis and pericarditis, which are inflammation and swelling of the heart and surrounding tissues and can be very serious. Based on clinical studies, myocarditis and/or pericarditis occur in 1 in 175 adults who get the vaccine for the first time.
In the ACAM2000 clinical trial experience, seven individuals of the 2,983 ACAM2000 first-time recipients and three individuals of the 868 Dryvax first-time recipients were suspected to have myocarditis/pericarditis. There were no cases in those subjects who had been vaccinated previously.
Serious health problems, including those that are life-threatening, can also occur in unvaccinated people who are accidentally infected by someone who has recently received the vaccine. In particular, unvaccinated people who are pregnant, or have problems with their heart or immune system, or have skin problems like eczema, dermatitis, psoriasis, and have close contact with a vaccine recipient are at an increased risk for serious problems if they become infected with the vaccine virus, either by being vaccinated, or by being in close contact with a person who was vaccinated. It is very important for the ACAM2000 recipient to properly care for the vaccination site to prevent the virus in the vaccine from spreading and infecting another part of the body and other people.
These types of serious adverse events are similar to those that occur with other smallpox vaccines.
More commonly observed side effects include: itching, sore arm, fever, headache, body ache, mild rash and fatigue.
A healthcare provider may decide not to give ACAM2000 if a person has a weakened immune system (e.g., leukemia, HIV, AIDS, transplant recipients, people with cancer that has spread, and those undergoing treatment with medicines that suppress the immune system such as steroids, prednisone, and cancer drugs). In addition, healthcare providers may decide not to vaccinate individuals with skin conditions such as eczema, dermatitis or psoriasis who are at increased risk of complications.
Every person who receives the vaccine is required to receive a Medication Guide approved by FDA. Medication Guides are printed handouts that are specific to particular medical products, and contain FDA-approved information that can help patients avoid serious adverse events. FDA requires that Medication Guides be issued when the Agency determines that:
ACAM2000 is the first vaccine licensed with a Medication Guide. FDA has determined that a Medication Guide is necessary for safe and effective use of the product because it could help prevent serious adverse events and inform the recipient of serious risks relative to benefit that could affect their decisions to be vaccinated.
It is the goal of FDA to minimize the risks that can occur with ACAM2000 and assure that the vaccine is given safely and effectively. To do this, a Risk Minimization Action Plan (RiskMAP), a strategic safety program, has been implemented for ACAM2000. The components of the RiskMAP include education, an adverse event reporting and collection system and risk management evaluation. Specifically, the manufacturer will implement the following components:
An FDA-approved Medication Guide will be given to each person who receives ACAM2000 to help achieve these education goals.
The evaluation program will include an annual adverse event report with an analysis of data from the Vaccine Adverse Event Reporting System and other sources to assess the presence of adverse events that may be attributable to weaknesses of components of the risk management program and summarize corrective actions undertaken. In addition, annual surveillance evaluations will be performed to ensure that vaccination adverse event reporting is sensitive and timely, and corrective actions taken in response will be outlined.
No, the manufacturer has stated that the vaccine won't be available to the public commercially, meaning it can't be obtained from a doctor's office. It has been purchased by the federal government for inclusion within the country's Strategic National Stockpile, for distribution by the Department of Health and Human Services in case it is ever needed.
Currently, designated U.S. military personnel receive the Dryvax vaccine and now that ACAM2000 has been licensed, this vaccine will be available to them. In addition, laboratory researchers working on certain pox viruses will also be eligible to receive the vaccine.
The vaccine is not recommended for use by the general population, as there is no smallpox disease in the world.