Despite Mixed Data, Sinovac's COVID-19 Vaccine is Second Most Used Globally

Sinovac_VCG/VCG via Getty Images

VCG/VCG via Getty Images

While several countries are relying on Sinovac Biotech’s coronavirus disease 2019 (COVID-19) vaccine to end the pandemic once and for all, concerns regarding the shot’s efficacy continue to shroud the vaccine, which is currently the second most used COVID-19 vaccine product across the globe.

Sinovac’s CoronaVac was the first COVID-19 vaccine approved in China for emergency use back in June 2020. Countries relying on the company’s vaccine typically have little access to the mRNA vaccines from Moderna and Pfizer-BioNTech. To date, approximately 380 million doses of this vaccine have been sent across the world.

And although the Beijing-based biotech’s vaccine has demonstrated success in clinical trials, efficacy rates have ranged from 50% to as high as 90% across clinical trials conducted in Turkey, Brazil and Indonesia. Sinovac has since kept mum on these data and hasn’t provided explanations or further details on why protection rates vary from study to study.

In an exclusive interview with Bloomberg, the company’s chief executive officer Yin Weidong indicated the priority has been to approve the vaccine by regulators versus addressing or explaining negative coverage in the media. He told the outlet that little else mattered as long as people were getting vaccinated against the novel coronavirus.

But Sinovac’s lack of media presence and inability to control data access from its trial partners may have tarnished the shot’s reputation, more so than it likely deserves. Real-world evidence suggests the company’s vaccine does indeed possess high levels of efficacy against COVID-19.

In an Indonesia trial, for instance, approximately 94% of 130,000 healthcare workers who were fully inoculated with Sinovac’s vaccine were reportedly protected from symptomatic infection with SARS-CoV-2. Another 96% of healthcare workers in this study were protected from COVID-19-related hospitalization and 98% were protected from death.

Despite these high rates of protection, the CEO of the company was reportedly unaware of this study and the corresponding data.

This lack of awareness didn’t stop the company from submitting other clinical and non-clinical research data to the World Health Organization, which on Wednesday authorized Sinovac’s two-dose CoronaVac COVID-19 vaccine for emergency use in people 18 years and older.

The European Medicine Agency has also started a rolling review of the company’s vaccine, which is the first step toward receiving EU approval for use.

Back in April, Sinovac completed the third phase of a vaccine bulk production manufacturing facility, resulting in the per-year production capacity exceeding 2 billion doses. To date, the total supply of CoronaVac has reached over 600 million doses, while incomplete data show more than 430 million doses have been administered across the globe.

In addition to pending approvals and authorizations, the United Arab Emirates recently reported it will start offering a third booster shot for people treated with the Sinovac vaccine. The country said the booster shot was to be used to counteract the less-than-anticipated antibody generation in some people who received the two-dose inoculation.

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