China’s CoronaVac exhibits exceptional efficiency in real life after poor show in clinical trials

By Sayujya S, Desk Reporter
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In an encouraging sign for several developing countries depending on the Sinovac Biotech vaccine, it has been found that the Chinese shot is wiping out COVID-19 among health workers in Indonesia.

Indonesia, one of the first countries to place its bet on the Sinovac vaccine which performed far worse than western vaccines in clinical trials, tracked 25,374 health workers in capital city Jakarta for 28 days after they received their second dose. They found that the vaccine protected 100 percent of them from death and 96 percent from hospitalization as soon as seven days after, said Health Minister Budi Gunadi Sadikin. The workers were tracked until late February.

Mr Sadikin also said that 94 percent 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.

Results from Brazil

The data adds to signs out of Brazil that the Sinovac shot is more effective than it proved in the testing phase, which was tainted with very low 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 percent, the lowest among all first-generation COVID-19 vaccines.

But the real-world examples also show that the Sinovac shot’s ability to control 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 percent 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, which is one of the fastest rates in the world, but not fast enough to stop the spread of the aggressive variant sweeping Latin America.

Preventing virus transmission

A key question for all COVID-19 vaccines is whether they can prevent or deter actual transmission of the virus. It is not clear whether the Sinovac shot, a traditional inactivated vaccine, can stop or reduce the virus from being contracted in the first place, but the fact it is preventing serious illness and death is more commendable.

The vaccine’s apparent effectiveness is also a major win for the country amid criticism that Chinese vaccine developers disclosed less data and were less transparent about severe adverse events compared with western companies.

Meanwhile, vaccine experts opine that the ability of vaccines to control a disease can be higher in the real world than when measured in clinical trials.

Related: China’s ‘Sinopharm’ vaccine gains WHO approval for emergency use