To date there is no vaccine to protect against human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS). Of all diseases for which there vaccine development has been attempted HIV/AIDS is perhaps the most difficult target. This is in large part due to: HIV having very high rate of mutation and recombination during viral replication, the lack of good correlates of immune protection, and there not being a small animal model for testing. Two large HIV vaccine trials recently failed — a vaccine candidate in Phase 2b/3 testing failed in 2020 and another vaccine candidate in Phase 2b failed in 2021.

One potentially promising development is continued progress in understanding of and elicitation of broadly neutralizing antibodies. Another promising recent development is the use of the mRNA vaccine platform for new vaccine candidates, with the National Institutes of Health recently having launched a Phase I study of 3 mRNA vaccine candidates.

This question is specifically asking about a vaccine against HIV-1, which when compared to HIV-2 is the more virulent and more infectious type of HIV and the cause of the vast majority of HIV infections worldwide

The purpose of this question is to understand if there will be an approved HIV-1 vaccine. HIV/AIDS is estimated to kill over half a million people every year, according to UNAIDS. The successful development of a HIV vaccine is also an important marker for general progress in vaccinology, given the difficulties encountered thus far in developing a vaccine against HIV.