Mixing Covid Vaccines Gives Good Protection, UK Study Suggests

BBC News, June 28, 2021.

A mix-and-match approach to Covid vaccines - using different brands of jab for first and second doses - gives good protection against the pandemic virus, a UK study has found. The Com-Cov trial looked at the efficacy of either two doses of Pfizer, two of AstraZeneca, or one of them followed by the other. All combinations worked well, priming the immune system. This knowledge could offer flexibility for vaccine rollout, say experts.

The UK's deputy chief medical officer, Prof Jonathan Van-Tam, said there was no reason to change the current successful same dose vaccine schedules in the UK, however, given vaccines were in good supply and saving lives.

But he says it might be something to look at in the future: "Mixing doses could provide us with even greater flexibility for a booster programme, while also supporting countries who have further to go with their vaccine rollouts, and who may be experiencing supply difficulties."

Some countries are already using mixed doses. Spain and Germany are offering the Pfizer or Moderna mRNA vaccines as a second dose to younger people who have already received a first dose of the AstraZeneca vaccine, following concerns about rare but serious blood clots, rather than about efficacy...

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https://www.bbc.com/news/health-57636356