The only vaccine against HIV still being tested in final clinical trials has proven to be ineffective, its manufacturer announced this week.
Dozens of other HIV vaccine candidates have been tested and discarded over the past decades. This latest setback delays progress towards a vaccine against the virus by three to five years, according to experts. Still, there are other options in testing, but everything is in the early stages.
The loss of this latest attempt highlights the challenges of designing a vaccine for such a powerful adversary as HIV. Four decades after its discovery, the virus still infects about 1.5 million people each year and kills around 650,000.
For people in wealthier nations, HIV is no longer the death sentence it once was. Powerful drugs can inactivate the virus in infected individuals. There are several options available to prevent the onset of infection: oral pills and injections administered every two months are already approved in the United States, for example, and an injection that would only need to be administered every six months is in the final stages of testing.
But these medications must be taken for the rest of the patient’s life and are often inaccessible to those who need them most. A vaccine would be the ideal way to prevent the spread of the virus.
It is estimated that 40 million people live with HIV worldwide. About 10 million of them do not have access to treatment.