THE LATEST results for China’s CoronaVac vaccine, developed by Sinovac Biotech, a Beijing-based pharmaceutical company, were disappointing for the aspiring scientific and technological powerhouse. Phase-three trials, which were conducted on health-care workers in Brazil, yielded an efficacy rate of just 50.7% (with a 95% confidence interval of 35.7% to 62.2%), just barely above the 50% threshold set by the World Health Organisation for covid-19 vaccines (see chart). The results of a real-world trial released a week earlier were even worse: the vaccine was estimated to be just 49.6% effective (11.3% to 71.4%) against symptomatic covid-19 cases; when asymptomatic infections were included, this figure dropped to a dismal 35.1%.
The Chinese authorities’ reaction did little to boost confidence. After news broke of the discouraging results, Gao Fu, head of the Chinese Centre for Disease Control and Prevention, admitted at a conference on April 10th that current vaccines “don’t have very high rates of protection”, and suggested that vaccines could be mixed to improve efficacy. Mr Gao later backtracked from the comments, claiming that it was “a complete misunderstanding”.
Publication Date: 15 April 2021
Publication Site: The Economist