HHS secretary Robert F. Kennedy Jr. has long been suspicious of mRNA vaccines, and in May he announced that HHS would no longer recommend mRNA Covid-19 vaccines for healthy children and pregnant women. The same month, he canceled a $590 million contract with Moderna, one of the mRNA Covid vaccine manufacturers, for a bird flu vaccine based on the same technology. “The problem with mRNA is that the first clinical application was the most political thing on the planet,” says Kagan, referring to the mRNA Covid vaccines. In June, the US Food and Drug Administration approved new labeling for Moderna’s and Pfizer’s mRNA Covid vaccines to emphasize this risk. After the success of the mRNA Covid-19 vaccines, the US government invested more heavily in mRNA technology.