John McNeil was certain of two things early on in his career: he would become a doctor and he would not follow in his parents' military-service footsteps. But burdened with debt after medical school at Wake Forest University in Winston-Salem, North Carolina, and Harvard School of Public Health, he reluctantly broke his pledge and joined the army for a health-profession scholarship. It was the start of a 23-year military career at the cutting edge of HIV vaccinology.

While finishing his residency at Walter Reed Army Hospital, McNeil also pursued an MS in public health at Harvard, and turned his focus to vaccines. He was among the first to use diagnostic tests for HIV infection. “My interest in infectious diseases and public health got swept up in AIDS,” he says of the early days of the epidemic. He spent the late 1980s documenting the frequency and distribution of HIV infection in new populations. In the 1990s, he identified candidate HIV vaccines to test in Thailand — an ideal location because of its low genetic diversity. McNeil retired from the army in 2003, a day after the start of a 16,000-person phase III efficacy trial for one of his candidate vaccines. He decided his army work was complete; the best opportunities were elsewhere.

So McNeil moved to the vaccine research centre at the US National Institutes of Health. There, he shepherded candidate vaccines into larger field trials and explored new approaches such as DNA vaccines. Lamenting the limited cross-fertilization of ideas among experts in HIV, malaria and tuberculosis, McNeil became increasingly interested in applying his knowledge of HIV to malaria. Recent work on inducing cellular immunity to HIV should be more vigorously applied to malaria, he suggests.

Jim Tartaglia, vice-president for R&D at Sanofi Pasteur's facility in Canada, recommended McNeil for his latest post, as scientific director of the Program for Appropriate Technology in Health's Malaria Vaccine Initiative. He lauds McNeil's experience with novel vaccine-development technologies and his ability to partner industry, academia and non-governmental organizations, a crucial skill for developing vaccines in multiple international locations.

McNeil acknowledges the many challenge ahead: for example, developing live virus vector approaches to induce immunity early on in malaria's complex life cycle. Nevertheless, he remains optimistic, and predicts that there will be an effective malaria vaccine within the decade.