FDA grants emergency use authorization for Moderna and Johnson & Johnson's COVID vaccine booster shots

The FDA on Wednesday granted emergency use authorization to booster shots from Moderna and Johnson & Johnson, clearing a key regulatory hurdle for millions of Americans looking to boost their protection against COVID-19. Adults can now also "mix and match" their booster shots, the FDA said, and do not have to get an additional dose from the same brand that first vaccinated them.

Like with Pfizer's vaccine, the FDA is authorizing a third Moderna shot for all seniors first vaccinated at least six months ago. Other adults at high risk of exposure or severe COVID-19 will also be eligible for booster shots under the FDA's decision.

Regulators are also allowing all 15 million adult recipients of Johnson & Johnson's COVID-19 vaccine to receive a second dose at least two months after they were first vaccinated, regardless of their personal risk. Ahead of the decision, the FDA's scientists had said that the highest estimates of vaccine effectiveness from the single-shot vaccine were "consistently less" than from Pfizer or Moderna.