A staff member of Sinovac Biotech, a Chinese biopharmaceutical company, displays a dose of COVID-19 inactivated vaccine in Schering bottle package in Beijing, capital of China, Dec. 23, 2020. Photo: Xinhua
The report by a Chilean university that has been cited by some foreign media as proof that Chinese company Sinovac Biotech's COVID-19 vaccine is not protective cannot represent the vaccine's real efficacy in Chile, as it is based on limited open data and "not even close to being a research paper," the Global Times learned from a source.
The official and overall data from the rollout of the CoronaVac vaccine will be released next week by Chile's Ministry of Health, the Global Times learned from Sinovac Biotech on Sunday.
Liu Peicheng, director of Sinovac Biotech's public relations department, said at a press conference on Sunday that Phase III clinical trials in Brazil, Indonesia, Turkey and Chile showed that the number of COVID-19 cases is far smaller in the vaccination groups than in the placebo groups.
No hospitalization, serious or fatal cases occurred in the vaccination groups, according to Liu.
About 130 million doses of CoronaVac have been administered all over the world. No antibody-dependent enhancement effect has been observed during either mass usage or clinical research, Liu said.
Citing the report on the results of a study recently released by the University of Chile, AFP reported that CoronaVac is 56.5 percent effective in protecting recipients two weeks after the second dose, and 27.7 percent effective within the first two weeks.
But for a single dose, efficacy in the 28 days between the first and second dose was only three percent, AFP reported.
The result of the study has been used by some foreign media in alarming headlines saying that a single shot of the vaccine does not offer protection.
However, the Global Times learned from a source close to the matter that the data was only an "exercise" conducted by a research team of the university based on public data, which means it is not comprehensive or authoritative.
The data is "very limited, not even close to being a paper," the Global Times learned from the source.
Sinovac Biotech has kept close communication with Chilean authorities. So far, a preliminary analysis of current information shows that CoronaVac is effective in preventing infection of different strains of SARS-CoV-2, reducing the probability of hospitalization or admission into intensive care unit, the source said.
CoronaVac has been given approval for emergency use in various countries, such as Pakistan and Panama.
The World Health Organization is also reviewing the vaccine and estimates that it will be included in the organization's Emergency Use Listing by the end of April.
Vaccination with at least one dose of CoronaVac was associated with a 0.50-fold reduction in the odds of symptomatic SARS-CoV-2 infection during the period 14 days or more after receiving the first dose, according to a report release on medRxiv on Wednesday based on the rollout of the vaccine in Brazil.