News Home » Business » Brazil researchers now say China's Sinovac vaccine is 50% effective — lower than announced earlier

Brazil researchers now say China's Sinovac vaccine is 50% effective — lower than announced earlier

UniqueThis 8 Jan 12
Covid-19 vaccines developed by China's Sinovac Biotech are displayed during a press conference in Beijing on Sept. 24, 2020.

The Covid-19 vaccine developed by China's Sinovac Biotech is just 50.4% effective in a Brazilian trial — barely meeting the threshold for regulatory approval and well below the initially reported efficacy rate, according to several media reports.  

Brazil is the first to complete late-stage trial of the vaccine CoronaVac. The state-run Butantan Institute has been criticized by scientists and health experts for a lack of transparency in making public its trial data.

The institute reportedly delayed releasing trial results three times — which it blamed on a confidentially clause in its contract with Sinovac — and last week announced partial data that showed an efficacy rate that was later revised much lower.

Butantan said last week that CoronaVac was 78% effective among volunteers with mild to severe infections, reported the Wall Street Journal. But the institute said Tuesday that the overall efficacy rate fell to 50.4% when including "very mild" cases that did not require medical assistance, the Journal reported.   

In comparison, Covid vaccines from Pfizer-BioNTech and Moderna were found to be about 95% effective in their late-stage trials.

Sinovac did not immediately respond to CNBC's emailed request for comment.

Brazil and other developing nations have pinned their hopes on Chinese vaccines as wealthier countries snap up vaccines developed in the West.

Sinovac's CoronaVac vaccine is also cheaper and easier to transport because it can be stored in ordinary refrigerators — unlike the vaccines from Pfizer-BioNTech and Moderna that must be kept at subfreezing temperatures.

The South American country has reported more than 8.1 million Covid infections in total, the third highest number globally, according to data compiled by Johns Hopkins University. The country's death toll of over 204,000 is the second highest in the world, Hopkins data showed.

Butantan has requested for CoronaVac to be authorized for emergency use, reported Reuters. Brazil's health regulator Anvisa, which has stipulated a minimum 50% efficacy rate for vaccines in the pandemic, said it will meet on Sunday to decide, the news agency said.

In addition to Brazil, other developing countries including Turkey and Indonesia are also conducting trials on CoronaVac.

Indonesia on Monday approved the vaccine for emergency use — the first country outside China to do so after interim data from a late-stage trial showed that CoronaVac was 65.3% effective, reported Reuters.


Around the World

6479 news found.
Grid View
List View
  • 01/20: Red and Blue
  • Inauguration Live Updates: Biden takes office, moving quickly to implement agenda
  • Brooklyn Nets' Kyrie Irving returns, scores 37 points in double-overtime loss to Cleveland Cavaliers
  • Larry Scott's 11-year run as Pac-12 commissioner to end in June
  • Henry To'o To'o among 4 Tennessee players to enter portal after Jeremy Pruitt firing
  • NBA postpones sixth consecutive game for the Washington Wizards
  • NBA to enforce rules forbidding hugs, handshakes with midcourt security
  • Alex Ovechkin, 3 others on COVID-19 absence list as NHL fines Washington Capitals $100K for violations of protocols
  • Biden plans temporary halt of oil activity in Arctic refuge
  • Sources -- J.A. Happ, Minnesota Twins agree to deal
  • Answering the biggest injury questions for NFL conference championship playoff teams