But the side effects following mix-and-match vaccinations were short-lived and there were no other safety concerns, the researchers reported in the Lancet medical journal. It's something to keep an eye out for when giving mixed doses, the researchers said. They either got the AstraZeneca vaccine as both doses; AstraZeneca as a first dose and Pfizer as a second dose; the Pfizer vaccine as both doses; or the Pfizer vaccine as a first dose and AstraZeneca as a second dose. Fever was reported by 41% of the people who received the Pfizer vaccine first and AstraZeneca vaccine second, compared with 21% of the volunteers given the Pfizer vaccine for both doses. "This study will give us greater insight into how we can use vaccines to stay on top of this nasty disease."

Source: CNN May 12, 2021 22:41 UTC