China's Sinovac vaccine has "general efficacy" of 50.4% in Brazil trials, says Butantan

A coronavirus vaccine developed by China's Sinovac showed "general efficacy" of 50.38% in a late-stage trial in Brazil, the company's local partners said on Tuesday, revealing a more modest figure after pressure for more transparency.

On Thursday, Butantan officials had celebrated results showing 78% efficacy against mild COVID-19 cases, a rate they have since described as "clinical efficacy."

Ricardo Palacios, medical director for clinical research at the Butantan biomedical center in Sao Paulo, said the new figure included infections that were so mild or asymptomatic that they did not need clinical care.