Experimental mRNA HIV vaccine safe, shows promise in animals
An experimental HIV vaccine based on mRNA—the same platform technology used in two highly effective COVID-19 vaccines—shows promise in mice and non-human primates, according to scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Their results, published in Nature Medicine, show that the novel vaccine was safe and prompted desired antibody and cellular immune responses against an HIV-like virus. Rhesus macaques receiving a priming vaccine followed by multiple booster inoculations had a 79% lower per-exposure risk of infection by simian-human immunodeficiency virus (SHIV) compared to unvaccinated animals. The research was led by Paolo Lusso, M.D., Ph.D., of NIAID’s Laboratory of Immunoregulation, in collaboration with other NIAID scientists, investigators from Moderna, Inc. and colleagues at other institutions.
“Despite nearly four decades of effort by the global research community, an effective vaccine to prevent HIV remains an elusive goal,” said NIAID Director Anthony S. Fauci, M.D., chief of the Laboratory and a paper co-author. “This experimental mRNA vaccine combines several features that may overcome shortcomings of other experimental HIV vaccines and thus represents a promising approach.”
The experimental vaccine works like mRNA COVID-19 vaccines. However, instead of carrying mRNA instructions for the coronavirus spike protein, the vaccine delivers coded instructions for making two key HIV proteins, Env and Gag. Muscle cells in an inoculated animal assemble these two proteins to produce virus-like particles (VLPs) studded with numerous copies of Env on their surface. Although they cannot cause infection or disease because they lack the complete genetic code of HIV, these VLPs match whole, infectious HIV in terms of stimulating suitable immune responses.
Scanning electromicrograph of an HIV-infected H9 T cell.
This page was last updated on Friday, January 21, 2022