The most important finding of the study was that the Spike-protein neutralising antibodies found in the mixed vaccine groups were significantly higher than the same-vaccine groups.
On Thursday, the World Health Organisation issued interim recommendations on mixing Covid-19 vaccines developed by different manufacturers for both second and booster doses.
Following up first doses of AstraZeneca or Pfizer with second doses of other vaccines generates robust immune response against Covid-19, according to a study published in The Lancet
Doctors say people have been mixing different kinds of COIVD-19 vaccine shots. They're also seeing people get extra doses of Moderna and Johnson & Johnson shots, even though those boosters aren't authorized yet.