NIAID

A report of an individual infected with a second strain of HIV despite effective drug treatment following the first infection has researchers concerned. “For the first time, we’ve shown it is possible for an individual to become infected with two closely related strains of HIV,” says Bruce D. Walker, M.D., a researcher at Massachusetts General Hospital and Harvard Medical School. The findings underscore the challenges vaccine developers face in creating a broadly effective vaccine against HIV. The first HIV vaccines may not prevent infection altogether, but rather may prevent HIV from causing disease by limiting the virus’ ability to reproduce, explains Dr. Walker. This case shows that a hypothetical vaccine against one strain of HIV may not necessarily protect the vaccinee against other, closely related strains.