HIV is widely considered to present the scientific community with a “daunting scientific challenge”, as stated by Dr Anthony Fauci in 2022. However, a recent publication in Science Translational Medicine reveals positive results from a primate study.
The publication states that a “challenge” to the development of an HIV vaccine is the “need to induce a polyclonal neutralising antibody (nAb) response in vaccine recipients”. Dr Barton Haynes of Duke School of Medicine, speaking to Technology Networks, suggests that this is because of the “similarity of the Env regions of HIV” as well as the “complexity of the antibodies that are required to interact with Env-neutralising sites”. For him, this is the “most difficult vaccine problem of all tried to date”.
The recent primate study by researchers at Duke investigated the potential offered by a “stabilised HIV-1 envelope trimer mixed with a Toll-like receptor 7/8 agonist”. This is an adjuvant used in vaccines against hepatitis B, EBV, and varicella zoster. The results demonstrated that macaques that had been vaccinated with this candidate “developed potent nAbs that targeted multiple sites on the envelope, including the CD4 site”. Thus, protection against “mucosal simian-human immunodeficiency virus” was afforded. Dr Haynes states that “HIV does not grow well in monkeys”, so “SHIV” can be used to “test an HIV envelop vaccine”.
This might be the “first step” in the production of a successful candidate, according to Haynes. Clinical trials are set to begin shortly to see if this vaccine can boost a similar candidate.
“My hope is that current studies identifying the specific steps needed for broadly neutralising and protective antibodies will teach us not only to make a successful HIV vaccine, but also teach us how to engineer the immune system for making many difficult-to-make vaccines”.
To learn more about HIV vaccine candidates get your tickets to the World Vaccine Congress in Europe, 2022.