A much debated HIV vaccine may actually lose its protective effect after a year.
Nelson Michael, one of the researchers who trialled the vaccine on over 16,000 people in Thailand, told a conference in San Francisco that the reason the results of the trial have been somewhat unclear may be that the protection offered by the vaccine wears off.
“It is very likely that this vaccine only worked for a short period of time. It is a weak, a modest effect but something that we can build on,” Michaels, a researcher at the Walter Reed Army Institute of Research, told Reuters.
“Is that ideal? No. But it is true there are vaccines like the flu vaccine where you have to get them every year.”
Although the vaccine was hailed as a success when the trial results were announced, some have since questioned how good the results actually are.
“Because the history of preventive interventions against HIV has been so poor, the HIV research community has seized on this [trial],” Peter Smith, of the London School of Hygiene & Tropical Medicine, told Nature News last year. “There is not much evidence from the data that it protects at all.”
At the time, Nature described the circumstances surrounding announcement of the results as “troubling” in an editorial.
Michael, speaking at the Conference on Retroviruses and Opportunistic Infections, said he was now working on follow up trials in Asia or Africa.