As discussed in our previous posts about human immunodeficiency virus (HIV), there exists no cure for this potentially life-threatening disease. Despite significant progress of symptom management for chronic conditions using antiretroviral therapy (ART), there is still a goal to develop an effective HIV vaccine to replace it. In this blog post, we aim to provide an overview of HIV vaccination, recent advances and remaining challenges.
Traditionally, HIV vaccines are made using one or a combination of the following ingredients: a weakened/inactive form of the virus or particles representative of unique viral features [1]. Ideally, viral structures represented by the vaccine will be recognized and remembered by the immune system, then antibodies can quickly clear out HIV upon the actual viral infection.
Although the vaccination approach seemed easy, the history of HIV vaccination development has had numerous setbacks. In the 1990s, the earliest HIV vaccine was developed, but failed to provide protection against viral infection, and sometimes even leads to increased infection in recipients [1]. The RV144 vaccine was the first to display effectiveness, with 60% more efficacy at 12-months post vaccination [2]. However, it still failed due to its inconsistencies across multiple clinical trials [1].
HIV is highly mutable, and with its primary target being CD4+ T cells, HIV can easily evade immunity [1]. However, there have been promising breakthroughs: broadly neutralizing antibodies (bNAbs) and an mRNA vaccine that encodes for HIV proteins. The bNAbs bind to structurally unaltered unique regions of HIV and can target multiple HIV strains, proven efficient as ART replacements [3,4]. However, the cost of production and the frequency of antibody injections limited large scale use of bNAbs. Fortunately, scientists are investigating its mechanism of action to screen for particles that can be used as vaccine candidates [5]. The mRNA vaccine that encodes for HIV proteins had candidates that entered clinical trials in 2022 [6]. More detail on mRNA vaccine development here.
Even though the development of HIV vaccine is critical, there are many challenges to face and more work to be done. Recent advancements of bNAbs and mRNA vaccines may further guide effective HIV vaccines. We will definitely make a post about its findings in the future!
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Written by: Hedi
Edited by: Natasha
BioDecoded is a volunteer group committed to sharing accurate scientific information. For more information about vaccines and their safety profile, please see previous posts or consult with your personal physician. If you have any questions about this topic, please comment or send them to our email.
References:
Ng’uni T, Chasara C, Ndhlovu ZM (2020). “Major Scientific Hurdles in HIV Vaccine Development: Historical Perspective and Future Directions”, Frontiers immunology, 11: 590780. Available at: https://www.frontiersin.org/articles/10.3389/fimmu.2020.590780/full
Rerks-Ngarm S, et al. (2009). “Vaccination with ALVAC and AIDSVAX to prevent HIV-1 infection in Thailand”, New England Journal of Medicine; 361(23):2209-2220. Available at: https://www.nejm.org/doi/full/10.1056/nejmoa0908492
Atkinson B, et al. (2023). “Replacement of ART with HIV Broadly Neutralizing Antibodies to Maximize the Effectiveness of Chemotherapy in HIV Patients with Lung Cancer”, AIDS Res Hum Retroviruses. Available at: https://pubmed.ncbi.nlm.nih.gov/37053110/
Eroshkin AM, Leblanc A, Weekes D, et al. (2014). “bNAber: database of broadly neutralizing HIV antibodies”, Nucleic Acids Res; 42:D1133. Available at: https://academic.oup.com/nar/article/42/D1/D1133/1048421
Cohen J. (2013). “Bound for glory”, Science; 341(6151):1168-1171. Available at: https://www.science.org/doi/10.1126/science.341.6151.1168
NIH launches clinical trial of three mRNA HIV vaccines | National Institutes of Health (NIH). Available at: https://www.nih.gov/news-events/news-releases/nih-launches-clinical-trial-three-mrna-hiv-vaccines (Accessed April 28, 2023).
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