China’s covid vaccine has four different efficacy rates

A few days before the global launch of vacuna from Sinovac Biotech Ltd. With the Indonesian president’s live inoculation, uncertainty revolves around the effectiveness of China’s main vaccine, for which four different rates of protection have been published in recent weeks.

Indonesia, which tracks the fastest pace of distributing the Sinovac vaccine to its population, reported that a local trial showed 65% efficacy against COVID-19. But only 1,620 people in Indonesia participated in the trial, a sample too small to obtain meaningful data.

Turkey said last month that the same vaccine showed 91.25% efficacy in its local trial, which was also too small to draw any meaningful conclusion.

In Brazil, where the largest Sinovac trial with more than 13,000 people is underway, different efficacy rates have been published. The company’s local partner in the trials, the Butantan Institute, reported last week that the vaccine was 78% effective in preventing mild cases of Covid-19 and 100% effective against severe and moderate infections.

However, a local news website reported this week that the “real” rate of effectiveness was between 50% and 60%, citing unidentified sources. The Butantan Institute said it was “speculative” and would release additional data on Tuesday.

This isn’t the first time that there has been an overlap in efficacy data in the COVID-19 vaccine race – AstraZeneca Plc showed two different rates of protection based on different dosing regimens last month – and all conclusions They are above the effective threshold of 50% required by regulators for approval.

However, the confusion, which arises as various governments pledge to vaccinate their citizens with the Sinovac vaccine, is leading to skepticism about Chinese vaccines, for which less safety information has been released, and for major Western vaccines. . The confusion of the data risks further undermining confidence in the vaccines President Xi Jinping has pledged to share with the rest of the world as a global public good.

“There is enormous financial and prestige pressure for the results of these trials to be exaggerated,” said Nikolai Petrovsky, professor in the School of Medicine and Public Health at Flinders University.

“In many cases, these exaggerations are also politically motivated, as countries that failed to adequately control the pandemic now want to exaggerate the benefits of vaccines to gain votes and defuse local unrest.”

A spokesperson for Sinovac declined to comment on numbers from its trials in Brazil, Turkey and Indonesia, noting that its Brazilian partner will release more data this week.

The data problem appears to be delaying regulatory approval of the Sinovac vaccine in some countries.