Brazilian health officials: Chinese COVID-19 vaccine is 78 percent effective

A COVID-19 vaccine developed by a Chinese company is effective, Brazilian officials said Thursday, announcing results of a large clinical trial. 

Brazil’s Butantan Institute tested the vaccine in more than 12,000 health workers in phase three trials and found it was 78 percent effective at preventing illness. The vaccine prevented all workers from developing mild or serious illness from COVID-19.

Beijing-based Sinovac has already sold more than 300 million doses to low- and middle-income countries, according to The New York Times.

Brazil and Indonesia will roll out the vaccine this month, according to Reuters.

The vaccine appears less effective than vaccines authorized for use in the U.S. Moderna and Pfizer’s vaccines are about 95 percent effective but are mostly being bought up by wealthier countries in the West.