Adams, who served as surgeon general during the first Trump administration, said Kennedy's assertions about the efficacy of mRNA vaccines are "simply not true."

In justifying the government's termination of $500 million in funding for mRNA vaccine projects, Health and Human Services Secretary Robert F. Kennedy Jr. falsely claimed mRNA vaccines "fail to protect effectively" against COVID-19 and suggested they are unsafe.

The US Department of Health and Human Services (HHS) plans to cancel $500m (£376m) in funding for mRNA vaccines being developed to counter viruses that cause diseases such as the flu and Covid-19.