The only vaccine against H.I.V. still being tested in late-stage clinical trials has proved ineffective, its manufacturer announced on [January 18], another disappointment in a field long beset by failure.
Dozens of H.I.V. vaccine candidates have been tested and discarded over the past few decades. The latest defeat sets progress toward a vaccine back by three to five years, experts said. Still, other options in early-stage trials may yet turn out to provide a powerful bulwark against H.I.V., the virus that causes AIDS.
An ongoing study called PrEPVacc in Eastern and Southern Africa is evaluating a combination of experimental H.I.V. vaccines and preventive drugs. Scientists have made headway in developing powerful antibodies that can neutralize the virus. And they are testing new vaccine technologies, including mRNA, against H.I.V.
Still, the loss of the latest candidate underscores the challenges of designing a vaccine for an adversary as wily as H.I.V. Four decades after its discovery, the virus still infects about 1.5 million people each year, and kills about 650,000.
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The news should prompt policymakers and activists to think of ways to make the existing tools for preventing H.I.V. more widely accessible, he added: “It’s not that all hope is lost, it’s that we need to redirect our resources to greatest impact.”
