A mixed vaccination of first AstraZeneca and then a Pfizer Covid-19 shot boosted neutralizing antibody levels by six times compared with two AstraZeneca doses, a study from South Korea showed.<br /><br />The study involved 499 medical workers - 100 receiving mixed doses, 200 taking two doses of the Pfizer/BioNTech shot and the remainder getting two AstraZeneca shots.<br /><br />The South Korean study also analysed neutralizing activity against major variants of concern, the Korea Disease Control and Prevention Agency (KDCA) said.<br /><br />- Reuters -
