The Department of Health and Human Services plans to cancel contracts and pull funding for some vaccines being developed to fight respiratory viruses like COVID-19 and the flu.

Robert F. Kennedy Jr. announced in a statement Tuesday that 22 projects, totaling $500 million, to develop vaccines using mRNA technology will be halted.

“I don’t think I’ve seen a more dangerous decision in public health in my 50 years in the business,” said Mike Osterholm, a University of Minnesota expert on infectious diseases and pandemic preparations.