Sinovac COVID-19 vaccine yields neutralizing antibodies in Phase II, titers not revealed

Sinovac’s disclosure over the weekend of early clinical data from its COVID-19 vaccine makes it the third company to demonstrate production of neutralizing antibodies in humans, behind Moderna and CanSino. Sinovac’s data come from many more patients, upping the confidence level, but without disclosure of the titers it’s hard to make even rough predictions about efficacy.

Sinovac Biotech Ltd. (NASDAQ:SVA) reported Saturday that over 90% of the 600 volunteers in the Phase II portion of a Phase I/II trial generated neutralizing antibodies (NAb) against SARS-CoV-2 at 14 days after prime-boost administration of CoronaVac. That rate is on par with the eight subjects Moderna Inc. (NASDAQ:MRNA) reported data from in May, and higher than data from 108 subjects in a study from CanSino Biologics Inc. (HKEX:6185) the same month...