January 21, 2022

Mixed vaccine schedules in people vaccinated with CoronaVac (SinoVac)

A study looking at immune responses after a booster vaccine in people whose first two doses were the CoronaVac (SinoVac) vaccine has been published in the Lancet.

CoronaVac has been used widely in many countries in Latin America, Africa and Asia.

The study was funded by the Ministry of Health in Brazil and conducted by researchers from Brazil and the University of Oxford – Professor Sue Ann Costa Clemens CBE of the Oxford Vaccine Group was chief investigator for the trial in Brazil.  It looked at antibody levels in people who had had two doses of CoronaVac (SinoVac) and who were then given a booster vaccine dose of either the Oxford-AstraZeneca, Pfizer, Janssen or SinoVac vaccine, and sought to find out whether being boosted by a vaccine different from the first two doses was associated with any difference in antibody levels after the booster.

The study looked at immune responses against variants including Delta and Omicron.

Journalists dialled in to this briefing to hear from the scientists who carried out the study and to ask any questions.

Speakers included:

Prof Sir Andrew Pollard, Director of the Oxford Vaccine Group and lead of the study

Prof Teresa Lambe OBE, Professor of Vaccinology & Immunology at the Oxford Vaccine Group and co-author of the study

Prof Merryn Voysey, Lead Statistician at the Oxford Vaccine Group and co-author of the study