Covid-19 vaccines developed by Sinovac Biotech in China will be on display during a press conference in Beijing on September 24, 2020.
Wang Zhao | AFP | Getty Images
The Covid-19 vaccine developed by China’s Sinovac Biotech is only 50.4% effective in a Brazilian study – according to several media reports it hardly reaches the threshold for official approval and is far below the originally reported effectiveness rate.
Brazil is the first country to complete the late-stage CoronaVac vaccine. The state-run butantane institute has been criticized by scientists and health experts for a lack of transparency in the publication of its test data.
The institute reportedly delayed publication of the trial results three times – attributing it to a confidential clause in its contract with Sinovac – and announced partial dates last week showing an effectiveness rate that was later revised much lower.
Butantane said last week that CoronaVac was 78% effective in volunteers with mild to severe infections, the Wall Street Journal reported. But the institute said Tuesday The Journal reported that when “very mild” cases that did not require medical attention were included, the overall effectiveness rate dropped to 50.4%.
In comparison, Covid vaccines from Pfizer-BioNTech and Moderna were found to be around 95% effective in their late-stage studies.
Sinovac did not immediately respond to CNBC’s email request for comment.
Hope for China’s vaccines
Brazil and other developing countries have put their hopes in Chinese vaccines as wealthier countries in the West buy developed vaccines.
Sinovac’s CoronaVac vaccine is also cheaper and easier to transport because it can be stored in regular refrigerators – unlike Pfizer-BioNTech and Moderna’s vaccines, which must be stored at freezing temperatures.
According to the Johns Hopkins University, the South American country has reported more than 8.1 million Covid infections, the third highest number worldwide. The country’s death toll is the second highest in the world at over 204,000, according to Hopkins data.
According to Reuters, butantane has applied for CoronaVac to be approved for emergency use. Brazilian health authority Anvisa, which has set a 50% or more efficacy rate for vaccines against the pandemic, said it would meet on Sunday to decide, the news agency said.
Try in other countries
In addition to Brazil, other developing countries, including Turkey and Indonesia, are also carrying out tests with CoronaVac.
Indonesia on Monday approved the emergency vaccine – the first country outside of China to do so after preliminary data from a late-night study showed CoronaVac was 65.3% effective, Reuters reported.