Mixed AstraZeneca-Pfizer Shot Boosts COVID-19 Antibody Level – New Study

By Staff, Agencies

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.

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.

All showed neutralizing antibodies, which prevent the virus from entering cells and replicating, and the result of the mixed schedule of vaccines showed similar amounts of neutralizing antibodies found from the group that received two Pfizer shots.

An earlier UK study showed similar results, comparing mixed two-dose schedules of Pfizer and AstraZeneca vaccines and finding that in any combination, they produced high concentrations of antibodies against the coronavirus spike protein.

The South Korean and UK studies provide support for the decision of several countries that have started offering alternatives to AstraZeneca as a second shot after the vaccine was linked to rare blood clots.