|An employee inspects vials containing CoronaVac, Sinovac Biotech's vaccine against the coronavirus disease (COVID-19), at Butantan biomedical production center in Sao Paulo, Brazil Jan 12, 2021. (Photo by= REUTERS/Amanda Perobelli)|
[Asia News Communication = Reporter Reakkana] A coronavirus vaccine developed by China's Sinovac Biotech was 50.4 percent effective at preventing symptomatic infections in a Brazilian trial, researchers said on Tuesday (Jan 12), barely enough for regulatory approval and well below the rate announced last week.
The latest results are a major disappointment for Brazil, as the Chinese vaccine is one of two that the federal government has lined up to begin immunization during the second wave of the world's second-deadliest COVID-19 outbreak. Several scientists and observers blasted the Butantan biomedical center for releasing partial data just days ago that generated unrealistic expectations. The confusion may add to skepticism in Brazil about the Chinese vaccine, which President Jair Bolsonaro has criticized, questioning its "origins".
"We have a good vaccine. Not the best vaccine in the world. Not the ideal vaccine," said microbiologist Natalia Pasternak, criticizing Butantan's triumphant tone. Last week, the Brazilian researchers had celebrated results showing 78 percent efficacy against "mild-to-severe" COVID-19 cases, a rate they later described as "clinical efficacy". Ricardo Palacios, medical director for clinical research at Butantan, said on Tuesday that the new lower efficacy finding included data on those "very mild" cases. Piecemeal disclosures about Chinese vaccine trials globally have raised concerns that they are not subject to the same public scrutiny as US and European alternatives.