“It’s not a problem associated with Pfizer. This is actually a problem associated with the Sinovac vaccine, and in other countries, they are now starting to think about booster vaccinations, even six months out from an original vaccination for some of these vaccines as well,” Mak said.
Experts see the toll in Brazil, already the highest in Latin America, climbing far higher.
“I think we are going to reach 700,000 or 800,000 deaths before we get to see the effects of vaccination,” Gonzalo Vecina, former head of Brazilian health regulator Anvisa, said, predicting a near-term acceleration in fatalities.
“We are experiencing the arrival of these new variants, and the Indian variant will send us for a loop.”
Evidence from neighboring Chile, which has also relied overwhelming on a vaccine developed by China’s Sinovac Biotech, suggests it may be months before mass immunization will effectively curb transmission.
Nearly half of Chileans have been vaccinated, but their capital Santiago just went back into lockdown as cases again surged to near peak levels.
Raphael Guimaraes, a researcher at Brazilian biomedical center Fiocruz, said delays in the Sinovac vaccination program in Latin America’s most populous nation meant that its full effects wouldn’t be felt until September or later.
Guimaraes warned that Brazil could revisit scenes from the worst of its March–April peak, when the country averaged 3,000 deaths per day.
“We are still in an extremely critical situation, with very high transmission rates and hospital bed occupancy that is still critical in many places,” he said.
This week, new confirmed cases in Brazil accelerated to more than 70,000 per day on average, edging past India for the most cases in the world.