Brazil on Sunday recorded 1,803 new Covid-19 deaths, as a large study found that a Chinese vaccine that has become the linchpin in the country's vaccination campaign is 50.7% effective against the infectious new homegrown variant known as P1.
Brazil, which has in recent weeks become the global epicenter of the coronavirus pandemic, saw over 37,000 new cases, the Health Ministry said on Sunday. With over 353,000 deaths, Latin America's biggest country has the second highest coronavirus death toll in the world, after the United States.
The outbreak has recently reached its most severe phase due to a lack of federal restrictions, a patchy vaccine rollout and the P1 variant.
Sao Paulo's Butantan biomedical institute, which tested and is now producing the CoronaVac vaccine developed by China's Sinovac Biotech Ltd, said on Sunday a study it conducted found the shot had an efficacy rate of 50.7% against the P1 variant, and a less widespread strain known as P2.
Brazilian President Jair Bolsonaro, a China hawk and vaccine skeptic who has come under fire for his handling of the outbreak, initially said his government would not buy the Sinovac shot, but later made a U-turn as his government struggled to secure supplies. Since then, the Chinese shot has become the most widely administered one in the country.
Butantan said that if the second dose is delayed by more than two weeks, the efficacy rises to 62.3%. The vaccine has an efficacy of between 83.7% and 100% at preventing those infected from requiring medical assistance, it said.
The study, which it said had been sent to the medical journal The Lancet for publication, tested 12,400 volunteers across Brazil.