BEIJING: China’s Sinovac Biotech said on Monday that a clinical trial in Brazil showed its COVID-19 vaccine was almost 20 percentage points more effective in a small sub-group of patients who received their two doses longer apart.
The protection rate for 1,394 participants who received doses of either CoronaVac or placebo three weeks apart was nearly 70%, a Sinovac spokesman said.
Brazilian researchers announced last week that the vaccine’s overall efficacy was 50.4% based on results from more than 9,000 volunteers, most of whom received doses 14 days apart, as outlined in the trial protocol.
The spokesman said a small number of participants received their second shot late due to a various reasons, without elaborating.
The dosing interval for COVID-19 vaccines has become a hot topic of debate among scientists, regulators and governments.
UK regulators have said a COVID-19 vaccine from AstraZeneca and Oxford University is more effective when there is a longer gap between doses…
