COVID-19 vaccine update | Uncertainty over Sinovac shot’s effectiveness an issue despite trail results in Brazil, Turkey

Workers unloading the 1.2 million doses of COVID-19 vaccine made by Sinovac, upon its arrival from Beijing at Jakarta's international airport in Tangerang on December 6, 2020. (PC-AFP)

Amid the final phase of trials for China-based Sinovac Biotech Ltd.’s coronavirus vaccine in Brazil and Turkey, uncertainty over the effectiveness of the shot in protecting people from the deadly virus has become an issue. Though Sinovac claims a protection rate on either side of 90 percent.

Sinovac, which is finalising results of phase III trials -- carried out in Brazil, Chile, Turkey, and Indonesia -- has conducted tests independently in these countries from each other under different protocols, rather than subjecting to unified norms, Bloomberg reported.

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Earlier this week, Brazilian researchers delayed releasing complete information on Sinovac’s vaccine and stated that the vaccine is found to be over 50 percent effective. On Thursday, Sao Paulo state Health Secretary Jean Gorinchteyn confirmed that Sinovac vaccine "didn’t reach 90%" efficacy, making it less successful than those developed by Pfizer Inc. and Moderna Inc.

"We don’t know how much more than 50% it was, whether it was 60%, 70% or 80%, but it’s at levels that allow us to reduce the impact of the disease on our population. We knew that the effectiveness would never reach 90%," Bloomberg quoted Gorinchteyn saying in an interview with Brazil’s CBN Radio.

Meanwhile, the Turkish administration had stated that the Sinovac vaccine's trial showed an estimated efficacy rate of 91.25 percent, which is based on only 29 cases. While Sinovac spokesman has not commented on this issue.

Considering the case of Sinovac vaccine's less requirement against Pfizer and Moderna, the Chinese drug can be proved more effective to inoculate more people around the world and save lives, especially in developing countries like Brazil. Sinovac's COVID-19 vaccine shots can be kept at normal refrigerator temperatures, unlike Pfizer and Moderna which require deep-freezers.