More frequent side-effects reported mixing Pfizer and Oxford Covid jabs, study suggests

However, UK trial found two doses of the same vaccine triggered less adverse reactions

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Administering one dose of the Pfizer/BioNTech vaccine followed by one of the Oxford/AstraZeneca vaccine (or vice versa) induces a higher frequency of mild to moderate side-effects compared with standard two doses of either vaccine, initial data from a key UK trial suggests.

The Oxford-led Com-Cov study is exploring the safety and efficacy of mixed-dose schedules given that they are being considered in several countries - including the UK - to fortify vaccine rollout programmes that are dependent on unstable vaccine supplies.