As a major South African HIV vaccination trial gets underway a new study suggests its benefits could be undercut by vaccine-resistant strains. 

Well-intentioned trials of HIV vaccination could lead to hundreds of thousands of unanticipated infections because of a sting in the tail of the vaccine, according to a new study.

A team led by Joshua Herbeck from the University of Washington used mathematical modelling to estimate the rate at which HIV vaccination caused vaccine-resistant virus to evolve, a process known as adaptation.

In a scenario where 70% of the population was vaccinated, the researchers calculated that within 10 years up to 250,000 new HIV cases could arise solely as a result of resistant-strains.

“Our results predict that HIV adaptation in response to vaccination may have a considerable, and detrimental, public health impact,” they write in the article, which was lodged on pre-print website biorxiv in late February, ahead of peer review.

The issue is of particular concern in South Africa, where the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates 19.2% of adults live with HIV.
South Africa is also the venue for HVTN 702, touted as the largest HIV vaccination trial ever to take place in that country.

Read the full article in Cosmos magazine here