Coronavirus: Pfizer booster may better protect than third CoronaVac shot, finds Turkish study
- Researchers at Manisa Celal Bayar University studied several hundred health workers vaccinated with CoronaVac, with boosters beginning in July
- China began rolling out Covid-19 boosters in several provinces this month and overseas countries are supplementing the CoronaVac regimen with other vaccines

The findings, which were released in an announcement this week and have not undergone peer review, come as countries around the world are deciding whether to provide booster shots to bolster protection against Covid-19 and are seeking to optimise that protection.
“The [Pfizer/BioNTech] vaccine applied in the third dose of vaccine showed a significant superiority in protection – both in terms of antibody level and disease status – compared to the third dose of CoronaVac vaccine,” the researchers said.
However, all of the nearly 500 participants receiving three doses of vaccine achieved protective antibody levels, “regardless of third-dose vaccine preference”, they said.
Hospital staff included in the study were vaccinated in January, as Turkey started its rollout of CoronaVac, and received their second doses in February. In July, Turkey began offering booster shots to hospital workers as concerns grew about the Delta variant and CoronaVac’s longevity and effectiveness against the highly transmissible strain.