Quality inspectors on Sinovac vaccine production lines use digital technology platforms to monitor the quality and efficiency of vaccine packaging on Sunday. (Photos: GT)

Sinovac’s COVID-19 vaccine is 100 percent effective in preventing severe and moderate infections, 77.96 percent effective in preventing mild cases, and has an overall efficacy rate of 50.4 percent, its final-stage clinical trials conducted in Brazil showed.

Experts say the result is good enough considering almost all participants are high-risk medical workers, and the 77.96 efficacy rate for mild-case protection means the vaccine can reduce 78 percent of people from needing hospitalization, effectively avoiding medical system collapse.

Almost all of the participants in the trials are medical workers at high risk of contracting the coronavirus. “The vaccine was able to 100 percent prevent severe illness in such a high-risk population, and effectively control the morbidity, and protect at least 50% of people from infection, which is good enough,” Wang Guiqiang, Director of the Infectious Disease Department at Peking University First Hospital, told the Global Times on Tuesday.

“Currently, the manufacturer requires a 0-14 vaccination doses program (Day 1 for first dose, Day 14 for the second dose), but this probably cannot bring the highest level of antibody which then partly lowered the efficacy result. That’s why some manufactures asks for a 0-21 vaccination program. But overall, its protective effects in such high-risk population is good enough,” Wang stressed.

The manufacturer requires recipients receive two doses 14 days apart, and if this was not adhered to, the efficacy could have been higher, Wang said.

Covax said it predicts that higher effectiveness will be seen in community use, and that it expects the vaccine to have a very high effectiveness among the general population similar with trials in other countries.