The number of military personnel admitted to US Army hospitals as the result of infectious diseases was much higher than admissions due to wounds or other injuries incurred in WWII or the wars in Korea, Vietnam or the Persian Gulf.1
It is not surprising; therefore, that since George Washington first ordered mandatory variolation of new recruits to the Continental Army to prevent smallpox in 1777, vaccination of military personnel has been a crucial component of deployments (reviewed in refs. 2
). Because of the large number of diverse endemic disease pathogens encountered by military personnel around the world, it is also not surprising that the US Department of Defense (DoD) has historically maintained an extensive vaccine research and development program, and that those vaccines have been important for civilian as well as military populations. For example, military sponsored research contributed to the Food and Drug Administration (FDA) licensure of 10 vaccines between 1945 and 1995, to include vaccines for anthrax, plague, influenza, rubella, adenoviruses, meningococci, hepatitis B, typhoid, Japanese encephalitis, and hepatitis A (reviewed in refs. 2
), all of which have been widely used and have provided enormous benefits in both civilian and military settings. Other licensed vaccines for naturally occurring diseases, such as those for yellow fever, mumps, measles, chickenpox and polio, were developed with the guidance of former military researchers. In addition to these FDA-licensed vaccines, several vaccines; for example, against malaria, tularemia, Dengue, HIV-AIDS, Chikungunya, Rift Valley fever, Argentinian hemorrhagic fever, and hemorrhagic fever with renal syndrome (HFRS), have been developed and tested in clinical studies by the military but have not yet been, or never will be, licensed.
Not only are endemic diseases of concern for the military, so are potential exposures to agents deliberately introduced into the environment through biological warfare (BW) or bioterrorism, to include toxins such as ricin, botulinum toxin, Staphylococcus enterotoxin B, and pathogens causing anthrax, plague, tularemia, glanders, smallpox, Ebola and Marburg hemorrhagic fevers or Venezuelan, eastern or western equine encephalitis. Further, genetically engineered novel threats are now a possibility, which has expanded the scope of military vaccine research and development.
Because it is recognized that some of these same BW or endemic disease agents are also potential threats to civilians, significant funds have been programmed for the Biomedical Advanced Research and Development Authority (BARDA) to stockpile vaccines against a few of the most likely pandemic disease threats or bioterrorism agents, such as pandemic influenza, anthrax and smallpox. Although there is overlap in the missions of BARDA and DoD, their ultimate goals differ in that BARDA focuses on countermeasures for treating the population after exposure to a bioterrorism agent or in response to a pandemic, whereas the DoD aims to provide protective immunity to the armed forces prior to exposure. Today, however, while vaccination of deployed troops remains a matter of national security, the cost of vaccine development has increased to the point where, without innovation and renewed commitment, the current scope of military vaccine development efforts is not sustainable.