Sinovac Biotech Ltd.’s vaccine is wiping out Covid-19 among health workers in Indonesia, an encouraging sign for the dozens of developing countries reliant on the controversial Chinese shot, which performed far worse than western vaccines in clinical trials.
Indonesia tracked 25,374 health workers in capital city Jakarta for 28 days after they received their second dose and found that the vaccine protected 100% of them from death and 96% from hospitalization as soon as seven days after, said Health Minister Budi Gunadi Sadikin in an interview on Tuesday. The workers were tracked until late February.
Sadikin also said that 94% of the workers had been protected against infection an extraordinary result that goes beyond what was measured in the shot’s numerous clinical trials though it’s unclear if the workers were uniformly screened to detect asymptomatic carriers.
“We see a very, very drastic drop,” in hospitalizations and deaths among medical workers, Sadikin said. It’s not known what strain of the coronavirus Sinovac’s shot worked against in Indonesia, but the country has not flagged any major outbreaks driven by variants of concern.
The data adds to signs out of Brazil that the Sinovac shot is more effective than it proved in the testing phase, which was beset by divergent efficacy rates and questions over data transparency. Results from its biggest Phase III trial in Brazil put the shot known as CoronaVac’s efficacy at just above 50%, the lowest among all first-generation Covid-19 vaccines. A spokesman for Sinovac in Beijing said the company cannot comment on the Indonesian study until it acquires more details.
In a separate interview with Bloomberg Tuesday, Sinovac’s chief executive officer Yin Weidong defended the disparity in clinical data around the shot, and said there was growing evidence CoronaVac is performing better when applied in the real world.
But the real-world examples also show that the Sinovac shot’s ability to quell outbreaks requires the vast majority of people to be vaccinated, a scenario that developing countries with poor health infrastructure and limited access to shots cannot reach quickly. In the Indonesian health worker study, and another in a Brazilian town of 45,000 people called Serrana, nearly 100% of people studied were fully vaccinated, with serious illness and deaths dropping after they were inoculated.
In contrast, Chile saw a resurgent outbreak after vaccinating over a third of the population of 19 million — one of the fastest rates in the world, but not fast enough to stop the spread of the aggressive variant sweeping Latin America.
“The earliest group of people vaccinated in Chile are old people. Less than 15 million of doses given to Chile means only 7 million people can get our shots. That equals to only 36% of a population of 19 million,” said Yin. “It’s normal that the country sees a resurgence of infections as social activities increase among the younger people who are mainly not inoculated.”
Among people vaccinated with CoronaVac in Chile, 89% were protected from serious Covid-19 that requires intensive care, said Yin. The vaccine’s protection is likely to vary from place to place due to virus variants, but Sinovac’s shot appears to be holding up well against the new mutations of concern, he said.