Research Roundup: HIV vaccines start human trials, new potential treatment for schistosomiasis, and antibody treatment helps prevent COVID-19
Moderna is launching human trials for two new HIV vaccines based on the mRNA technology used in its COVID-19 vaccine, the company announced last week. The phase 1 trial will recruit 56 participants between the ages of 18 and 50 to assess the vaccines’ safety and ability to generate a broad range of neutralizing antibodies against HIV. The two vaccine candidates, mRNA-1644 and mRNA-1574, are designed to combat HIV by inducing broadly neutralizing antibodies to levels not previously obtained by other shots. The antibodies can then target multiple variants of HIV and neutralize stable parts of the virus that won’t change as much as it mutates. The study, expected to run until May 2023, is a first step in a long, complex process, according to researchers.
Researchers have discovered a series of drug compounds that are highly effective against the three main species of parasitic worms that cause human schistosomiasis, according to new research published in PLOS Neglected Tropical Diseases. Currently, the only treatment for schistosomiasis is praziquantel, which is effective at a high dose against adult worms, but less so against juvenile worms, requiring repeat treatment. The new research involved screening more than 300,000 compounds to evaluate their ability to kill the worms, compared against praziquantel. The researchers identified a series of promising new drug candidates that appeared safe and highly effective against adult and juvenile worms—in a single dose around 10 times smaller than required for praziquantel. The drugs are now being explored by Merck Global Health Institute as a potential treatment for schistosomiasis.
In phase 3 trial results, AstraZeneca’s COVID-19 antibody treatment, AZD7442, significantly reduced the risk of developing COVID-19 symptoms. The drug, a combination of two long-acting antibodies, reduced the risk of developing symptoms by 77 percent when given to patients who had not been exposed to COVID-19. No participants who were given the treatment developed a severe form of the disease. The monoclonal antibodies used in AZD7442, which mimic the body's natural immune response, were modified to be more long-lasting, potentially affording up to 12 months of protection. The drug could be particularly useful as a preventative treatment in patients for whom vaccines might be less effective, including immunocompromised individuals, AstraZeneca said in its statement. The company plans to submit the phase 3 results to a peer-reviewed journal and file for regulatory approval of the drug.