A recent study by the researchers from South Korea revealed that mixed vaccination of first AstraZeneca followed by a Pfizer COVID-19 shot boosted neutralizing antibody levels by six times compared with two AstraZeneca doses.
The study researchers included 499 medical workers, out of which 100 received mixed doses, 200 received 2 doses of the Pfizer/BioNTech shot, and the remaining participants got two AstraZeneca shots.
All showed neutralizing antibodies, and the result of the mixed schedule of vaccines showed better amounts of neutralizing antibodies compared to the group that received two Pfizer shots.
Last month, a British study showed similar results – an mixed vaccines AstraZeneca and Pfizer produced the best T-cell responses and a higher antibody response compared to Pfizer followed by AstraZeneca.
The South Korean study also analyzed neutralizing activity against major variants of concern, the Korea Disease Control and Prevention Agency (KDCA) said.
None of the groups demonstrated reduced neutralizing activity against the Alpha variant, first identified in Britain. Still, the neutralization titer decreased by 2.5 to 6 fold against Beta, Gamma and Delta, first detected in South Africa, Brazil, and India, respectively.