This was one in a continuing line of moves that have put Kennedy's vaccine skepticism into public policy, though scientists say the vaccines are safe.

U.S. Health Secretary Robert F. Kennedy Jr. incorrectly argued mRNA vaccines are ineffective to justify the Department of Health and Human Service's recent decision to cancel $500 million in government-funded research projects to develop new vaccines using the technology.

This speeding up of the production process is one of the key reasons mRNA vaccines have "long been distrusted by vaccine sceptics". Kennedy himself referred to mRNA vaccine technology as "troubled", and called older "whole-cell" vaccine technology "safer".