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".

If anyone needed a reminder that US health secretary and fervent anti-vaccine advocate Robert F. Kennedy Jr. has no background in science or medicine, look no further than the video he posted on social media Tuesday evening.

Stephen Colbert is not impressed that Robert F. Kennedy Jr. has cut $500 million in funding for vaccines. On the latest episode of The Late Show, Colbert took aim at the Health and Human Services Secretary over the decision, which former Surgeon General Jerome Adams said “is going to cost lives.”