Why do some people infected with the virus that causes AIDS become overwhelmed by the virus while others are able to hold the pathogen in check? Scientists writing in a recent issue of the journal Science say the answer seems to centre on variations in the genetic makeup of people, a finding so deceptively simple that it has drawn the attention of high-ranking administrators at the National Institutes of Health.

NIH director Elias A Zerhouni said the research “could lead to improved HIV therapies and provides new targets for vaccine developers”. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, one of the 19 institutes in the NIH, praised the work as revealing how genetic factors influence how a host responds to infection.

“People vary greatly in their vulnerability to HIV infection,” Barton Haynes, who heads an HIV/AIDS centre, said in a statement. “In particular, there are striking and largely unexplained differences between individuals in the degree to which they are able to hold viral levels to a low set point in the period soon after infection.

“If scientists could pinpoint the gene variants that help some people control HIV infection — or avoid it altogether — they might be able to rationally design therapies or vaccines to mimic these naturally occurring genetic advantages,” Haynes added.