For the first time our team has investigated the longevity of neutralising antibodies in HIV-1-infected individuals. It is currently believed that an HIV-1 vaccine can only be effective if it induces these antibodies in vaccinated individuals. The findings improve the understanding of the dynamics of such antibodies and are an important building block for further HIV-1 vaccine research. The study was led by Professor Dr Florian Klein, Director of the Institute of Virology at the University Hospital of Cologne, and Dr. Dr. Philipp Schommers, Head of the Laboratory of Antiviral Immunity in the Department of Internal Medicine at the University Hospital of Cologne. The paper, entitled 'Dynamics and durability of HIV-1 neutralisation are determined by viral replication', has been published in the journal Nature Medicine.
Dr. Schommers, first author of the study, said: "We were able to show that HIV-1 neutralisation activity in patients is strongly dependent on the amount of virus in the patient. While this dependence could be studied in other infectious diseases, such as COVID-19, shortly after the disease was first described, the longevity of neutralising antibodies in HIV-1 had not yet been shown in large studies".
Despite the availability of effective drugs that provide the basis for the treatment of HIV-1 infection and can effectively prevent the transmission of the virus, more than 1.2 million people become infected with HIV each year. The development of an effective HIV-1 vaccine is therefore still the subject of intense research.
Broadly neutralising antibodies (bNAbs) can prevent HIV-1 infection. Researchers are trying to induce such bNAbs in humans by vaccination. However, this has proved extremely difficult. As a result, no vaccines have been developed to induce bNAbs in humans. It is also unclear how long such broadly neutralising antibodies persist in humans. However, this knowledge is crucial for the development of successful HIV-1 vaccination strategies.
The researchers led by Professor Klein and Dr. Schommers therefore studied the HIV-1 antibody response in more than 2,300 patients from Germany, Tanzania, Cameroon and Nepal. They were able to identify several factors that cause patients to naturally produce neutralising antibodies. They also identified 'elite neutralisers', HIV-1-infected individuals who develop a very strong and broad neutralising antibody response. By studying HIV-1-infected individuals over time, the international research team was able to determine the dynamics of maintaining HIV-1-neutralising antibodies or further decreasing the concentration of these antibodies in the blood. It was shown that the antibody response in these patients declines over the years, but that highly potent bNAbs can be detected in them even after years. This is an important finding and suggests that a potential HIV-1 vaccine may be able to induce a durable vaccine response.
Link to the publication: https://www.nature.com/articles/s41591-023-02582-3
Research briefing: https://www.nature.com/articles/s41591-023-02592-1
News release of the University of Cologne: https://portal.uni-koeln.de/en/universitaet/aktuell/press-releases/single-news/another-step-toward-the-hiv-1-vaccine-dynamics-of-neutralizing-antibodies
