The U.S. Department of Health and Human Services said it is winding down development of messenger-RNA vaccines under its Biomedical Advanced Research and Development Authority. Health Secretary Robert F. Kennedy Jr. announced on 5 August that BARDA is cancelling or shrinking 22 contracts and funding solicitations—together valued at almost $500 million—because, he said, data show the platform does not reliably prevent upper-respiratory infections such as COVID-19 and influenza. The money, he added, will be redirected to “safer, broader vaccine platforms” including whole-virus approaches that he argues are less vulnerable to viral mutation. Projects hit by the decision include Moderna’s late-stage H5N1 bird-flu vaccine contract and pending proposals from Pfizer, Sanofi, CSL Seqirus, Gritstone and others. Some agreements nearing completion, such as Arcturus’s bird-flu candidate and Amplitude’s trans-amplifying RNA platform, will be allowed to finish, but HHS said no new mRNA programmes will be started. The move comes after earlier cancellations of a $766 million Moderna package and follows broader shake-ups at advisory panels within the department. Scientists and medical groups condemned the cutbacks, warning they will weaken U.S. readiness for future pandemics and bioterror threats. The American Medical Association urged the administration to restore the research, while epidemiologist Michael Osterholm called the decision “the most dangerous” public-health step he has seen in five decades. National-security specialists said mRNA technology, which enabled rapid COVID-19 vaccine rollout and is being explored for cancer therapies, is critical to maintaining a fast response capability. President Donald Trump is expected to meet Kennedy to review the cancellations amid mounting pressure from industry and public-health advocates.