Jul 22, 2010 (CIDRAP News) The US Centers for Disease Control and Prevention (CDC) today released new details about recommendations its vaccine advisory group made in February for Americans who receive anthrax shots.
In a full report on the Advisory Committee on Immunization Practices (ACIP) recommendations, published today in the CDC's Morbidity and Mortality Weekly Report (MMWR), the CDC outlines five changes, two of which it reported earlier when ACIP made its recommendations back in February. The CDC previously reported changes in the schedule and route of administration for BioThrax, also known as anthrax vaccine adsorbed (AVA), which is the nation's only licensed anthrax vaccine.
ACIP had recommended reducing the number of initial doses from six to five and changing the route of administration from subcutaneous to intramuscular. The two recommendations were based on the results of ongoing clinical trials designed to gauge if the long immunization series and side effects can be reduced. The shots are required for US military members who are deployed in high-risk areas such as the Middle East. Some military members have opposed anthrax vaccination because of side effects.
Today's MMWR report includes three other recommendations. ACIP recommended AVA as part of postexposure prophylaxis in pregnant women, provided guidance on preexposure vaccination of emergency workers and first responders, and recommended 60 days of antibiotic prophylaxis combined with three AVA doses for optimal postexposure protection of unvaccinated people.
ACIP based its recommendation for pregnant women on a recent study of military women who were inadvertently vaccinated with AVA while pregnant. Current Department of Defense policy exempts pregnant women from anthrax vaccination. The study suggested that women who received the vaccine during the first trimester had a slightly higher risk of experiencing birth defects than those not vaccinated or vaccinated after pregnancy. However, the finding wasn't statistically significant when the first-trimester group was compared with women vaccinated outside the first trimester.
After reviewing the study and discussing the finding with the authors, ACIP concluded that the AVA is safe to administer during pregnancy, but advised that women defer vaccination unless they face an immediate risk of anthrax exposure.
Though emergency and other responders aren't advised to routinely receive pre-event anthrax vaccination, ACIP now says that employers can offer responders who are involved in activities that might lead to aerosolized anthrax spore exposure the vaccine on a voluntary basis if the vaccination program is carried out under a supervised occupational health and safety program.
For combination AVA and antibiotic postexposure prophylactic treatment in unvaccinated people, ACIP extended the recommended length of antibiotic therapy from at least 30 days to at least 60 days for those exposed to aerosolized anthrax spores.
ACIP's recommendations are routinely approved by the CDC director and the secretary of the Department of Health and Human Services.
Jul 23 MMWR report
Feb 25 CIDRAP News story "ACIP OKs fewer anthrax shots, leaves flu-shot groups same"