Throughout history, vaccines have been successful in mitigating the effects of diseases like smallpox, polio, measles, and tetanus around the world—and vaccines continue to be the best defense against common, sometimes deadly infections, according to the Centers for Disease Control and Prevention.

The COVID-19 pandemic further demonstrated the importance of vaccine research and development, which continues to be a top priority for civilian and military health officials. Within the Department of Defense, several organizations work in tandem to advance vaccine development to protect service members and their families.

Combating Invisible Enemies

From a military standpoint, infectious diseases pose a significant risk to the operational effectiveness of the warfighter. With service members deployed in every part of the world, one way to maintain effectiveness is to develop vaccines against prioritized threats to the health of the joint force.

The Military Infectious Diseases Research Program focuses on vaccines to prevent or mitigate these threats. Part of the Defense Health Agency’s Research and Development organization at Fort Detrick, Maryland, the program’s mission is to plan, coordinate, and oversee requirements-driven medical solutions to maximize warfighter readiness and performance.

“Vaccines and other preventive medical countermeasures keep service members in the fight and minimize lost duty days,” said U.S. Army Lt. Col. Katie Carr, military deputy director for MIDRP. “We collaborate with government, academia, and industry partners to advance the research, development, and production of vaccines for diseases that occur in parts of the world where U.S. troops are deployed.”

The U.S. military has been a major innovator in vaccine development and DOD collaborations have led to the successful development of multiple vaccines to benefit military and public health, according to Carr. In fact, the Walter Reed Army Institute of Research has its roots in the Yellow Fever Commission, established by U.S. Army Maj. Walter Reed after the Spanish-American War, which pioneered a successful vaccine against the disease still in use today.

Other vaccines developed by the U.S. Army include those to prevent adenovirus, influenza, rubella, meningitis, and hepatitis. In 2019, decades of research performed at the U.S. Army Medical Research Institute of Infectious Diseases, another DHA Research and Development laboratory, supported the Food and Drug Administration’s approval of vaccines to protect against Ebola and mpox viruses.

Monitoring Emerging Threats

More recently, concerns about mosquito-borne infections have increased worldwide. One mosquito-borne pathogen, chikungunya virus, has been detected in widening geographic areas, likely due to climate change. Chikungunya may cause fever and joint pain, according to DHA-Public Health. It has been found in areas in Africa, the Americas, Asia, and Europe, as well as islands in the Caribbean, and the Indian and Pacific Oceans.

Only a few cases of chikungunya infection have ever been diagnosed in service members. Nonetheless, having a vaccine available in case of growing chikungunya threats is valuable, said Dr. Margaret Ryan, medical director for immunization health at DHA.

In 2023, a chikungunya virus vaccine received FDA approval using the accelerated approval pathway, which allows the agency to approve certain products based on evidence of a product’s effectiveness that is reasonably likely to predict clinical benefit. The vaccine is recommended by CDC for travelers going to locations with active chikungunya outbreaks, and the vaccine may be considered in other special situations.

Ryan noted the military uses all available vaccines to prevent mosquito-borne infections like chikungunya, Japanese encephalitis, and yellow fever, in accordance with CDC guidelines. Using other countermeasures to prevent mosquito bites remains extremely important, according to Ryan, because there are many mosquito-borne infections that are not yet vaccine-preventable.

Overseeing Vaccine Development

At DHA Research and Development, experts within the Warfighter Protection and Acute Care Project Management Office continually leverage innovations across the whole of government, industry, and academia, according to Dr. Kendra Lawrence, who heads the WPAC PMO.

“Vaccine development is extremely expensive, and partnering with industry helps DOD maximize return on investment,” Lawrence explained. “At U.S. Army Medical Material Development Activity, we work to identify the most promising solutions for preventing and treating infectious diseases of military importance. This reduces redundancy and maximizes efficiencies with research investments to ensure that commercial solutions can meet military needs.”

U.S. Army Col. Matthew Clark of the DOD’s Joint Program Manager for Chemical, Biological, Radiological, and Nuclear Medical, explains vaccines with a viable commercial market are the essential “engine” for preparedness for both biodefense and global health. A viable market, regardless of size, helps ensure the availability of a stable and steady supply for the warfighter and the public when needed.

“Partnerships are the flywheel that keeps the engine operating in top form. They can be as simple as information sharing or collaborations through cooperative research and development agreements to test commercial products within military-specific use cases,” said Clark. “As products mature, competitive prototyping and down-selection of potential solutions can result in more substantial investments from the DOD to advance products for FDA approval.”

The Office of Regulated Activities also plays a key role in helping to develop medical products for military use, according to U.S. Army Lt. Col. Victor Zottig, ORA’s deputy director. The office provides regulatory support to assist in advancing potential vaccines through the FDA pathway to final approval, post-marketing requirements, and fielding.

“ORA supports vaccine developers at both the USAMMDA and the Joint Project Manager CBRN Medical with regulatory consultation support,” said Zottig. “As a member of an integrated product team, we evaluate the commercial development partner’s regulatory strategy, as well as assisting with document preparation and facilitating their interactions with the FDA.”

Supporting Warfighter Readiness

To ensure DOD continues to focus on the right targets, Carr said a panel of stakeholders and infectious disease experts convene every three to four years to prioritize infectious disease threats to the military. “This panel helps to identify the diseases of top concern to the DOD and map out a plan for developing medical solutions in coordination with government and industry partners,” explained Carr.

“Through these collaborations,” said Carr, “the DOD is ensuring medical countermeasures are available for our warfighters so they can be ready to support the mission—no matter where they may be deployed.”