SAO PAULO (Reuters) – A coronavirus vaccine developed by China’s Sinovac Biotech was 78% effective in a late Brazilian trial without severe cases of COVID-19, researchers said on Thursday, although the lack of data prompted the need for greater transparency.
The results of the study, closely followed by vaccine-based developing countries to start mass vaccinations to help end a furious pandemic, were under preliminary findings by Turkish researchers and did not provide detailed data on US vaccines, and Europe.
The director of the Brazilian biomedical center Butantan, Sinovac’s research and production partner, said the detailed results are being passed to the Anvisa health regulator as part of a request for emergency use of the vaccine.
“One thing is to present at a press conference. It is different to obtain the data and analyze them, which will make Anvisa “, said Cristina Bonorino, who is part of the scientific committee of the Brazilian Society of Immunology. “If that’s what they say, that’s a great result,” she added.
Brazil and Indonesia, which have the most COVID-19 cases in Latin America and Southeast Asia, respectively, are preparing to launch the vaccine, called CoronaVac, this month. Turkey, Chile, Singapore, Ukraine and Thailand have also concluded supply agreements with Sinovac.
Although the effectiveness of CoronaVac does not exceed the 95% success rate of vaccines from Moderna Inc or Pfizer Inc with partner BioNTech SE, it is easier to transport and can be stored at normal refrigerator temperatures.
The 78% efficacy rate is also well above the 50% to 60% baseline set by global health authorities for vaccines developing at the beginning of the pandemic, given the urgent need.
Moderna and Pfizer / BioNTech published the results of late studies last year before receiving emergency use permits in the United States and elsewhere.
Butantan director Dimas Covas told a news conference that the full CoronaVac data will be published in an unspecified scientific publication, but did not provide a timeline.
Pressed by journalists, Covas said there were 218 COVID-19 cases in the trial of 13,000 volunteers. Just over 160 of these cases occurred among participants who received a placebo, and the rest were in vaccinated volunteers, he said.
Unlike other vaccine studies, the Brazilian study CoronaVac included elderly volunteers, a particularly vulnerable population.
Covas said CoronaVac completely prevented severe cases of COVID-19 among the vaccinated group, including the elderly. None of those who received the vaccine became ill enough to require hospitalization, he added.
A FEW DETAILS
The fragmentary disclosure of the results of the global CoronaVac studies led to concerns about the transparency of the processes, which was not helped by the Butantan press conference.
“It was not clear or transparent,” said Denise Garrett, an epidemiologist who worked for 23 years at the US Centers for Disease Control and Prevention (CDC). They presented secondary results on the prevention of mild, severe cases and hospitalizations, but not the effectiveness in preventing the disease.
Butantan’s partial disclosure, which had delayed its announcement three times, citing obligations to Sinovac, added to skepticism about the Chinese vaccine in Brazil. Nearly half of Brazilians said they would not get a COVID-19 vaccine developed by China, according to a December poll.
Brazilian President Jair Bolsonaro has expressed his contempt for the Sinovac vaccine, citing doubts about its “origin”. He exchanged beards with political rival João Doria, the governor of Sao Paulo, who is funding the film’s rehearsals and production.
However, Health Minister Eduardo Pazuello said on Thursday that the federal government will buy the full production of Butantan from CoronaVac this year, close to a deal to buy 100 million doses for a national immunization program.
Brazil has the second deadliest outbreak in the world after the United States, with more than 200,000 deaths on Thursday and aims to vaccinate 51 million people, or about a quarter of its population, in the first half of the year. 2021. [nL1N2JI32B]
Immunizations have not yet begun. Doria reiterated that Sao Paulo, the country’s richest and most populous state, expects vaccinations to begin on January 25th.
Based on traditional vaccination technology that uses inactivated coronavirus to trigger an immune response, CoronaVac can be stored at temperatures of 2-8 degrees Celsius (36 ° -46 ° F) and can remain stable for up to three years.
The vaccines offered by Pfizer / BioNTech and Moderna use a new synthetic messenger RNA (mRNA) technology, which requires much lower temperatures for transport and storage. The Pfizer / BioNTech vaccine should be kept at a sub-arctic temperature, making it an inefficient option for poor countries and areas without the necessary cold storage equipment.
Reporting by Eduardo Simões Additional reporting by Julie Steenhuysen, Ana Mano, Anthony Boadle and the Beijing Newsroom Edited by Brad Haynes, Miyoung Kim and Bill Berkrot