On September 3, 2021, China’s embassy in Bangkok published a statement on Facebook attacking what it called groundless allegations in Thailand about Chinese-made vaccines.
The statement claimed: “[S]ome Thai people and some organizations have underestimated and slandered Chinese vaccines for no reason.”
As evidence, the embassy cited data released on August 3 from the Chilean Ministry of Health that found Sinovac is 86 percent effective in preventing serious symptoms and deaths, as well as preventing hospitalization.
The embassy Indonesian government research released August 6 that said Sinovac was up to 95 percent effective in preventing death.
“This information is proof that Sinovac is not an inferior vaccine, as has been alleged,” the embassy said.
Although ‘inferior’ is a loaded term, and though Sinovac has indeed faced a lot of public scrutiny in Thailand, multiple studies do suggest that other vaccines are better at fighting off COVID-19.
For example, released by Chile’s Health Ministry on the effectiveness of the country’s vaccination program showed that Sinovac was less effective in preventing hospitalization, ICU admission and death than the Pfizer-BioNTech vaccine.
It found that Sinovac was 58.5 percent effective in preventing symptomatic COVID-19, 86 percent effective in preventing hospitalization, 89.7 percent effective in preventing ICU admission and 86.4 percent effective in preventing death.
By contrast, the Pfizer-BioNTech vaccine was 87.7 percent effective in preventing symptomatic COVID-19, 97.2 percent effective in preventing hospitalization, 98.3 percent effective in preventing ICU admission and 100 percent effective in preventing death.
The AstraZeneca vaccine proved 68.7 percent effective in preventing symptomatic COVID-19, and 100% effective in preventing hospitalization, ICU admissions and preventing death. Dr. Rafael Araos, a lead researcher for that study, the AstraZeneca vaccine had been monitored over a shorter period of time, and its results would have to be confirmed.
It should be noted that Chile’s vaccine strategy was heavily reliant on Sinovac (also known as the CoronaVac). The Sinovac recipients for that study were approximately 8.6 million people (versus 4.5 million for Pfizer-BioNTech and 2.4 million for AstraZeneca).
Surprisingly, the Chinese embassy in Bangkok did not cite a newer, September 2, 2021, published in The New England Journal of Medicine showing slightly higher efficacy rates for Sinovac.
That study, covering 102 million Sinovac recipients, found the vaccine was 65.9 percent effective in preventing symptomatic COVID-19, 87.5 percent effective in preventing hospitalization, 90.3 percent effective in preventing ICU admission and 86.3 percent effective in preventing death. (Adjusted figures for Pfizer-BioNTech and AstraZeneca were not provided.)
The Indonesian study higher rates of Sinovac’s efficacy than the Chilean study, at 85 percent effective in preventing symptomatic COVID-19, 92% effective in preventing hospitalization among older people, and 95 percent effective in preventing deaths. However, the study group was far smaller at 86,936, and the Indonesian study also did not offer comparative figures for other vaccines.
A preliminary version of covering 60.6 million people found that those who had taken the AstraZeneca vaccine (also known as Vaxzevria) had a 70 percent lower risk of infection, 86.8 percent lower risk of hospitalization, an 88.1 percent lower risk of ICU admission, and a 90.2 percent lower risk of death.
By contrast, those vaccinated with Sinovac had a 54.2 percent lower risk of infection, 72.6 percent lower risk of hospitalization, a 74.2 percent lower risk of ICU admission, and a 74 percent lower risk of death.
That study has yet to be peer-reviewed.
by Thai researchers on medRxiv, which publishes non-peer-reviewed work, found that Sinovac produces far fewer neutralizing antibodies — which can counter and kill infected cells — than a natural infection produces.
The World Health Organization (WHO) has not weighed in on the issue of which vaccine is best, “head-to-head” comparisons cannot be made “due to the different approaches taken in designing the respective studies."
However, the global health body added “all of the vaccines that have achieved WHO Emergency Use Listing are highly effective in preventing severe disease and hospitalization due to COVID-19.” The Sinovac for emergency use on June 1.
Meantime, the Thai government’s vaccine procurement strategy, and initial reliance on Sinovac, has been the subject of strong public criticism and suspicion.