The study on 19,000 people in the UK found one Pfizer shot was about 36% effective against Delta, but it was highly effective after two shots.
One dose of Pfizer or Moderna vaccines appears at least 80% effective against symptomatic COVID-19. For AstraZeneca, one-shot efficacy is 70%.
A single dose of Pfizer's or AstraZeneca's vaccines - both of which require two shots - was either weakly or not at all effective against Delta.
Canada supports mixing and matching vaccine doses - like following AstraZeneca with Moderna - but it's not approved in the US.
Five of them had gotten Covishield, an India-made version of AstraZeneca's shot, and one had gotten China's Sinopharm shot, Seychelles officials said.
Australians under 40 will soon be permitted access to the AstraZeneca COVID-19 vaccine, if they first discuss the potential side effects with their GP. Prime Minister Scott Morrison made the announcement Monday night, heralding a major turnaround to Australia’s vaccine program. Australian health authorities recommend the jab for those aged […]
The Wimbledon crowd celebrate Dame Sarah Gilbert and Sir Andrew Pollard at Centre Court on Monday, the first day of the British tennis tournament.
Some experts now think it's a good idea to get an mRNA booster shot after a dose of the AstraZeneca or Johnson & Johnson vaccines.
The Moderna COVID-19 vaccine is one step closer to rolling out in Australia after the Therapeutic Goods Administration (TGA) granted it provisional registration. The measure is the first step towards full TGA approval, and Moderna is expected to sign up “shortly”. The news comes as Australia plans to phase out […]
Some experts worry that Delta could cause more breakthrough infections. Others are concerned that it might evolve into an even more dangerous variant.
AstraZeneca and Johnson & Johnson's vaccines can cause "mutant" proteins to escape cells, triggering a response in blood vessels, the scientists say.
Two shots of Pfizer's vaccine were 88% effective against the variant first identified in India, and one shot was 33% effective, real-world data found.
One associate at the Emergent BioSolutions plant documented just one shower in 19 days of work, the FDA's report said.
Antibody levels were 40 times higher for people who got Pfizer's vaccine two weeks after AstraZeneca's, compared with people who only had one shot.
The Biden administration will give away 20 million leftover doses of Pfizer, Johnson & Johnson, and Moderna - plus 60 million AstraZeneca shots.
A study into vaccine-mixing - which is not policy in the US but is sometimes used in France, Germany, and the UK - found it was safe but unpleasant.
Israel, the US, the UK are getting shots into arms most quickly. Brazil, India, Japan, and South Korea trail further behind.