Breakthroughs Blog: HIV/AIDS

A new study sheds light on the findings of a recent trial evaluating the ability of a laboratory-made broadly neutralizing antibody (bnAb) to prevent HIV infection, pointing to approaches that could lead to more successful future antibodies and vaccines. bnAbs are naturally occurring antibodies that can neutralize multiple strains of HIV; they are considered a promising approach in HIV prevention research. A large, multicountry clinical trial evaluating a laboratory-made bnAb found that it did not significantly reduce overall HIV infections, although it showed some ability to reduce infections caused by highly sensitive strains. In the new study, researchers examined what happened in the participants who received the bnAb, discovering that there were extended periods of time when their antibody levels were too low to block less-sensitive strains of the virus. The study results suggest that more potent antibody concentrations and combinations of antibodies that attack the virus in different ways could have more success.An international research team has identified a crucial compound in the saliva of virus-carrying mosquitoes that could lead to a new prevention strategy for multiple mosquito-borne viruses. The researchers found that when mosquitoes infected with two orthoflaviviruses, West Nile virus and Zika virus, bite, their saliva contains not only the virus but also a viral compound that promotes infection by inhibiting the body’s initial immune response that is triggered when a virus enters the skin. The findings suggest that this viral compound could be shared among other orthoflaviviruses as well and could be a promising target for a preventive vaccine against multiple viruses from this group. The researchers have developed a vaccine targeting the compound that is now being optimized for clinical evaluation. New research from scientists in the United Kingdom highlights a new mechanism that a dangerous fungus uses to evade antifungal treatments. Candida auris is a priority pathogen that has caused outbreaks globally over the past two decades and can be highly fatal for vulnerable hospitalized patients. Current antifungal drugs work by targeting fungal cell walls, hindering the fungi from expanding. The researchers found that one way C. auris eluded treatment was by creating multiple versions of its entire genome, including a wide range of mutations in a specific gene that plays a key role in cell wall integrity. These findings point to new pathways for developing next-generation antifungals and combination antifungal regimens.

A study from the University of California, San Francisco found that a new long-acting HIV combination treatment could provide an alternative, more accessible option for some people with HIV. Long-acting treatment options can provide a simpler, more convenient alternative to daily pills for people living with HIV, but the only approved long-acting combination includes rilpivirine, which is not available in low- and middle-income countries, and the virus has been known to develop resistance to it and similar drugs. The new combination under study replaces rilpivirine with lenacapavir, which uses a different mechanism to target the virus. In the study, all participants achieved and maintained control of the virus. Additional clinical trials are planned to evaluate the approach more comprehensively, but, in the meantime, these findings could help guide care.  A team of researchers at the Massachusetts Institute of Technology has found a way to keep mRNA vaccines stable at higher temperatures, which could drastically lower costs and improve access to the technology in low-resource settings around the world. mRNA vaccines must be kept at extremely cold temperatures during transport and storage, requiring high costs and continuous monitoring. The researchers adjusted the formulation of the tiny particles that carry the mRNA, making them more resistant to heat. The vaccines the team produced can be stored at room temperature for up to a year or at nearly 100 degrees Fahrenheit for two months. Even after storage, the shots elicited equivalent immune responses in mice to the original formulations.The Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene and Tropical Medicine have launched a Phase 1 clinical trial in Uganda evaluating the safety and immune response of a vaccine candidate for Bundibugyo, the severe strain of Ebolavirus behind the ongoing outbreak in the Democratic Republic of the Congo for which there are currently no licensed vaccines. Conducted in partnership with the Oxford Vaccine Group and Pandemic Science Institute at the University of Oxford, the trial builds on an ongoing Phase 1 trial of the same candidate in the United Kingdom. Both trials are funded by the Coalition for Epidemic Preparedness Innovations (CEPI). The candidate, ChAdOx BDBV, was developed by scientists at the University of Oxford and uses the same platform as the Oxford/AstraZeneca COVID-19 vaccine. 

Last week, Gilead Sciences announced that it has expanded the scope of its voluntary licensing agreements with six manufacturing partners, who are already manufacturing the recently approved twice-yearly lenacapavir for HIV prevention, to include investigational once-yearly lenacapavir. Following the unprecedented Phase 3 trials for twice-yearly lenacapavir, an ongoing Phase 3 trial is evaluating a once-yearly option that could provide a full year of prevention with just one annual dose, further expanding prevention options and addressing persistent barriers to uptake and adherence. Establishing these agreements at this early stage helps manufacturers, regulators, health systems, and communities prepare for the broad, rapid, and equitable scale-up of the once-yearly option, if it is eventually approved. The World Health Organization (WHO) has updated its malaria guidelines to include Coartem® Baby, the first antimalarial developed specifically for newborns and young infants weighing between two and five kilograms. This patient group previously had no medicine specifically designed for their unique needs, leaving them to be treated with modified doses of formulations intended for older children, raising the risk of treatment failure or toxicity. The drug was developed by Novartis and partner Medicines for Malaria Venture (MMV), with financial support from the European & Developing Countries Clinical Trials Partnership and the Swedish International Development Cooperation Agency. WHO’s inclusion of Coartem® Baby in the guidelines informs and enables malaria-endemic countries to introduce the treatment in national malaria programs, supporting broader access. After receiving prequalification by WHO and approval from Swiss and Ghanian regulatory authorities, Coartem® Baby has so far been rolled out in 11 countries. The Coalition for Epidemic Preparedness Innovations (CEPI) recently announced that it is awarding $3.9 million to support research projects aimed at improving understanding of the Bundibugyo ebolavirus behind the ongoing outbreak in the Democratic Republic of the Congo. Specifically, the funding will support modelling and analytic teams led by the Institut National de Recherche Biomédicale, Imperial College London, and Makerere University School of Public Health. These teams will collect, integrate, and analyze outbreak data to guide the outbreak response; inform the design of fast, efficient vaccine clinical trials; and support longer-term preparedness against similar outbreaks in the region. To ensure long-term applicability, the partners have placed a strong emphasis on capacity strengthening and open sharing of data and methods, so that the tools and knowledge these projects generate can be utilized in future outbreaks in the region. 

Researchers from Stanford University and the Broad Institute have used artificial intelligence to create functional bacteriophages capable of destroying strains of bacteria that have evolved resistance to naturally occurring phages. Bacteriophages are common viruses that target and kill bacteria. The engineered bacteriophages performed comparably to naturally occurring relatives and were able to rapidly clear strains of Escherichia coli that had evolved resistance. This research could lead to the development of phage therapies capable of targeting rapidly evolving pathogens, although experts warn that safeguards are urgently needed to prevent the technology from being used for harm.A newly published study led by Oregon Health & Science University found that a one-time treatment regimen designed to be given to newborns with HIV within three days of birth permanently cleared the virus in nonhuman primates, offering hope of a way to mitigate the need for lifelong treatment for newborns infected with HIV. The therapy consists of neutralizing antibodies, standard antiretroviral therapy, and the experimental monoclonal antibody leronlimab, which, in previous studies, have failed individually to permanently clear the virus. Antiretroviral therapy is already approved, so pending the outcomes of ongoing clinical trials of the broadly neutralizing antibodies and leronlimab, the next step is to evaluate the combination regimen in people, initially in newly exposed adults.  A team of UK scientists have found in a first-in-human trial that a reformulated temperature-stable tetanus-diphtheria vaccine is comparable in safety and efficacy to two approved vaccines. Current vaccines need to be kept very cool throughout transport and storage, a very expensive and resource-intensive requirement that can lead to wasted supplies and limited access in low-resource settings. The scientists reformulated a licensed vaccine by drying it into a powder with trehalose, a sugar used by plants to survive in dry conditions, which is then reconstituted with water before administration. A larger trial is set to begin soon, which could be the last evaluation required because the original vaccine is already licensed.