A firm in China has become the latest to release data on its clinical trial program to develop a vaccine against Covid-19.
Beijing-based Sinovac Biotech announced Saturday what it called positive results from its Phase I/II clinical trial of CoronaVac, its vaccine against the virus that causes Covid-19, SARS-CoV-2. The vaccine uses an inactivated virus.
The company said the randomized, placebo-controlled trials enrolled 743 healthy volunteers aged 18-59. The ClinicalTrials.gov database lists two studies: One with 744 participants, in the city of Renqiu, Hebei province; and another with 422 participants, in Xuzhou, Jiangsu province. The company plans to file its Phase III trial protocol with the National Medical Products Administration, China’s drug and device regulatory agency, and said last week that it would work with Brazil’s Instituto Butantan to conduct a Phase III study.
The data released Saturday showed no severe adverse events, while the vaccine induced neutralizing antibodies 14 days after administration, while the neutralizing antibody seroconversion rate was 90%. While the company said that indicates the vaccine can induce a positive immune response, that does not necessarily indicate whether it is effective at preventing infection with SARS-CoV-2, or how long any protective benefit might last.
The announcement mirrors one that another company, Cambridge, Massachusetts-based Moderna, made last month, stating that preliminary Phase I data for its messenger RNA-based vaccine, mRNA-1273, also induced immune responses in participants. However, those data also did not indicate whether the vaccine would actually be effective in preventing Covid-19 or for how long. Moderna’s vaccine is currently in Phase II development and is planned to enter into Phase III next month, though the company has yet to publish data from its Phase I study.
On Monday, Politico reported that experts have become concerned that the Trump administration may pressure the Food and Drug Administration to grant emergency use authorizations to one or more vaccines before they have been definitively proven in clinical trials to actually be effective at preventing SARS-CoV-2 infection. The resulting widespread use of such a vaccine, the online publication reported, could make it more difficult to enroll patients into clinical trials.
The first company to publish data was another Chinese firm, Tianjin-based CanSino Biologics, which published data from its own Phase I study in The Lancet last month. The company has been developing its vaccine only within China, though it has also been working on taking it abroad, announcing a partnership last month with a federal research institution in Canada.
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