new anthrax vaccine, although it remains uncertain when a new vaccine will be available. In addition, some elements of the research program will be affected by DoD’s decision, announced in June 2002, to resume its anthrax vaccination program on a more limited basis than initially planned.
Although beyond CDC’s control, some of these factors make the timeline for the CDC research more critical. The results of many of the planned studies will help guide the use of AVA, as well as provide information relevant for the development of a new anthrax vaccine. However, with the push for a new vaccine, some data on AVA could conceivably come too late to be useful. The committee strove to focus on the research questions that exist regardless of these circumstances. The committee also acknowledges that the bioterrorist events have put great demands upon CDC and hopes that this report will provide advice that will help optimize the usefulness of the research program.
In response to a request from CDC, IOM convened the Committee to Review the CDC Anthrax Vaccine Safety and Efficacy Research Program in fall 2000.4 The IOM committee members brought expertise in microbiology; infectious diseases; vaccine research, development, and evaluation; postmarketing surveillance of adverse events; regulatory and licensing procedures; epidemiology; biostatistics; survey research and design; immunology; differences in disease between men and women; and health surveillance (see Appendix A for biographical sketches of the committee members).
The committee obtained information about CDC’s anthrax vaccine research program from written materials and oral presentations provided by CDC investigators. Military personnel and others with concerns about the safety or efficacy of AVA also made presentations and provided written materials. The committee issued an interim report in July 2001 (IOM, 2001). (See Appendix F for the interim findings and recommendations.) This final report is based primarily on the committee’s review of the materials provided by CDC in February 2002, supplemented by information gathered and discussed in the committee meetings. The materials provided in February 2002 describe the objectives and design of the proposed research studies and list critical research questions. (See Box ES-1 for a list of the proposed studies and Appendix C for a subset of the documents provided by CDC.)
The committee made an overall assessment of the CDC research plan (Chapter 7) and reviewed the specific studies proposed by CDC in the three areas of efficacy, safety, and acceptability (Chapters 4, 5, and 6, respectively). The committee also noted additional research needs that became evident following the bioterrorist events of 2001 and expressed concerns about the leadership of the research program (Chapter 7). Key findings and recommendations appear below, and a complete listing appears in Boxes ES-2, ES-3, ES-4, and ES-5.
CDC considered many of the findings and recommendations in the committee’s interim report in the further development of the studies comprising the anthrax vaccine safety and efficacy research program. After examining the components of the research program described in the February 2002 materials, the committee found the CDC response to the congressional mandate to be generally complete and appropriate. The clinical trial is appropriate and satisfactorily designed to address the congressionally mandated charge to optimize the vaccination schedule and the route of vaccine administration. The nonhuman primate (NHP) studies conducted in conjunction with the human clinical trial will largely address the challenge of determining immunologic correlates of protection (ICP) and documenting the efficacy of the vaccine.
The committee was not asked to evaluate the safety and efficacy of AVA. Another IOM committee asked to consider those issues found that AVA as currently administered should be effective against anthrax toxicity from all known strains of the bacterium, as well as from any potential bioengineered strains (IOM, 2002). AVA was also found to be reasonably safe, with reactions occurring soon after vaccination that are comparable to those observed with other vaccines regularly administered to adults. (See Appendix G for the findings and recommendations from that committee’s report.)