Study recommends booster jabs for older people immunized with CoronaVac

Booster Shot
Photo: Ravipat/Shutterstock

A preprint paper by the São Paulo Heart Institute (InCor), in partnership with the University of São Paulo, suggests that Sinovac’s CoronaVac immunizer is less effective in patients aged 55 and older. For these people, researchers recommended a third booster shot — preferably using another vaccine.

The study detected an immune response in 95 percent of vaccinated trial participants, against a 99-percent rate among those who recovered from a Covid-19 infection. São Paulo’s Butantan Biological Institute — which produces CoronaVac in Brazil — says the findings “do not mean older people are less protected.”

The matter of whether to administer booster shots in Brazil has revived political spats between São Paulo Governor João Doria — who initially brought CoronaVac to Brazil — and President Jair Bolsonaro, who portrays it as an ineffective and dangerous vaccine. 

Last week, Brazil’s federal health regulator Anvisa denied authorization for the emergency use of CoronaVac on children and teenagers aged 3 to 17. Anvisa also recommended booster shots for senior citizens and people with low immunity rates who were immunized with the CoronaVac. On August 18, Health Minister Marcelo Queiroga said booster rollouts will begin with health workers and senior citizens.