at their meeting.
The recommendations to the committee sought to optimize the use of Anthrax Vaccine Adsorbed (AVA) in post-exposure prophylaxis (PEP) in the event of a wide-area release of Bacillus anthracis spores. In this event, a mass vaccination effort would be undertaken, requiring expedited administration of AVA. ACIP now recommends that the intramuscular administration may be used over the traditional subcutaneous approach if there are any operational or logistical challenges that delay effective vaccination. Another recommendation from ACIP would allow two full doses or three half doses of AVA to be used to expand vaccine coverage for PEP in the event there is an inadequate vaccine supply. The committee also recommended that AbxPEP, an antimicrobial, be stopped 42 days after the first dose of AVA or 2 weeks after the last dose.
Carolina K. Smith, MD/Fotolia.com
William A. Bower, MD, of the division of high-consequence pathogens and pathology at the Centers for Disease Control and Prevention, and the anthrax work group looked at three nonhuman primate studies and eight human immunogenicity and adverse event studies during the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). All of the animal studies were used to predict human survival by vaccinating the nonhuman primates with AVA, then challenging them with B. anthracis. Using animal studies to predict human survival is common practice under the “animal rule.”
When Dr. Bower and the work group assessed the studies comparing intramuscular administration with subcutaneous administration of AVA, they rated the overall evidence as GRADE 2. However, they rated the adverse events data as GRADE 1.
Dr. Bower and his colleagues also reviewed dose-sparing studies to identify the feasibility of allowing two full doses or three half doses of AVA to be used to expand vaccine coverage for PEP in the event there is an inadequate vaccine supply. For these studies, the anthrax work group gave a GRADE score of 2.
The overall evidence score for microbial duration for PEP was judged to be GRADE 2.
“These forthcoming recommendations will be used by the CDC to inform state and local health departments to better prepare for an emergency response to a wide-area release of Bacillus anthracis spores,” said Dr. Bower.
The committee’s recommendations must be approved by the CDC’s director before they are considered official recommendations.
Dr. Bower did not report any relevant financial conflicts of interest.