Taking the first dose of and then AstraZeneca for the second can provide good protection against the pandemic virus, a study has found. The Com-Cov trial, led by researchers from the University of Oxford, looked at the efficacy of either two doses of Pfizer, two of AstraZeneca, or one of them followed by the other. The results showed that all combinations worked well, priming the immune system, the BBC reported. The study included 850 volunteers aged 50 and above, who were given the doses four weeks apart. The team found that people who took AstraZeneca shot followed by Pfizer showed higher antibodies and T cell responses than those who took Pfizer followed by AstraZeneca.

Both of these mixes induced higher antibodies than two doses of AstraZeneca, while the highest antibody response was seen after two doses of Pfizer, and the highest T cell response from AstraZeneca followed by Pfizer. "We already know that both standard schedules are very effective against severe disease and hospitalisations, including against the Delta variant when given at eight to 12 weeks apart," lead investigator Professor Matthew Snape, from varsity was quoted as saying. He however, added that the findings did not undermine the UK policy of giving people the same jab twice. But, they do offer such flexibility for vaccine rollout in the future.