The FDA has approved the first phase of human trials for a self-amplifying mRNA bird flu vaccine developed by Arcturus Therapeutics, funded by the US government and the Gates Foundation. This vaccine, targeting the H5N1 virus, introduces an enzyme prompting cells to produce more mRNA, leading to sustained antigen production, which experts warn could lead to prolonged immune activation and unknown health risks.
Epidemiologist Dr. Nicolas Hulscher described the FDA’s approval as an opportunity for Arcturus to “experiment with injecting humans with H5N1 bird flu replicon mRNA.” The clinical study is funded by the Biomedical Advanced Research and Development Authority (BARDA), a division of HHS focused on pandemic preparedness. Arcturus also recently received a $928,563 grant from the Gates Foundation, which has long supported mRNA research.
Arcturus claims self-amplifying mRNA vaccines can provide immunity with smaller doses. However, Hulscher warned that even a small dose might be more hazardous due to the vaccine’s self-replicating nature, as the extent of antigen production cannot be precisely measured or controlled.