An Experimental H.I.V. Vaccine Fails in Africa

An advanced H.I.V. vaccine trial in Africa has been shut down after data showed the shots offered only limited protection against the virus, researchers announced on Tuesday.

The vaccine, made by Johnson & Johnson, is one in a long line found to offer little defense against H.I.V., one of medicine’s most intractable adversaries. One candidate vaccine even increased the risk of infection.

Another trial was halted last year in South Africa after a different experimental vaccine failed to offer sufficient protection. Some 1.5 million people were infected with H.I.V. worldwide in 2020, and 38 million are living with the infection.

Scientists were dismayed by the most recent failure.

“I should be used to it by now, but you’re never used to it — you still put your heart and soul into it,” said Dr. Glenda Gray, the principal investigator of the trial and chair of the South African Medical Research Council. Dr. Gray has been working to develop an H.I.V. vaccine for more than 15 years.

Entirely new approaches may be needed. This month, Moderna announced that it would test a vaccine based on the mRNA platform used to devise the company’s coronavirus vaccine.

The trial, called Imbokodo, tested an experimental vaccine in 2,600 young women deemed at high risk of H.I.V. infection in five sub-Saharan African countries. Women and girls accounted for almost two-thirds of new H.I.V. infections in the region last year.