A container loaded with Sinovac vaccine doses is offloaded from a plane at Jakarta’s airport for human trials in Indonesia. Photo: Handout

One more foreign country has accredited the safety and efficacy of a Chinese vaccine. Brazil’s state-backed Butantan Institut and the health authority of the state of Sao Paulo have both corroborated claims from China’s Sinovac Biotech about its attenuated vaccine. 

Their endorsement is borne out by preliminary data from third-stage human trials in the South American country, still in the grip of Covid-19, that show the Chinese vaccine is “more than 50% effective” against the coronavirus.  

The conclusion from the final clinical trial involving about 13,000 people in Sao Paulo is that the vaccine, based on a weakened, detoxified form of the Covid pathogen and a flu virus, can trigger a significant immune response in more than half of the participants against a real infection.

That said, Brazilian officials have held back further details of their assessment as more data are embargoed until they have been checked and analyzed in China, in line with their agreement with Sinovac. 

Sao Paulo’s health chief Jean Gorinchteyn is quoted in reports as saying that a pilot immunization program using Sinovac’s product would proceed as planned. It has also been revealed that the Butantan Institut, as a distributor, may also sell the vaccine to Argentina, Uruguay, Peru, Ecuador and Honduras. 

Brazilian officials show Sinovac’s vaccine in Sao Paulo. Photo: Handout

Earlier this month, the United Arab Emirates approved a registration application from China’s state-owned SinoPharm for its attenuated vaccine to hit the local market next year, after the country’s evaluation of the trials held there found it was 85% effective against the disease. 

Specifically, the SinoPharm vaccine had a 99% seroconversion rate of neutralizing antibody and 100% effectiveness in preventing moderate and severe cases of the pneumonia caused by Covid-19 and that no severe side effects had been observed in the 31,000-odd participants.  

The World Health Organization’s recommended threshold for Covid vaccine approval is an efficacy rare of 50%. 

A Sinovac employee examines vaccine products at the company’s plant in Beijing. Photo: People’s Daily

The initial results from the UAE and Brazil may help induce more confidence in these Chinese alternatives to the vaccines from better-known Western producers such as AstraZeneca, Pfizer and its German partner BioNTech as they churn out doses for inoculation in the United Kingdom and some parts of the United States. 

But detailed, verifiable and easily accessible final-stage trial data about these Chinese vaccines are still lacking, and this has fueled the badmouthing and potential boycott by residents in jurisdictions like Hong Kong, Macau and Singapore that have announced plans and deals to import from Sinovac.

To discredit the product, critics cite previous vaccine scandals in China, the most notorious one being the 2018 expose of substandard and even fake DPT and rabies vaccines from a listed pharmaceutical firm in the northeastern Jilin province.

Still, governments in these places also urge that it will be unscientific to jump to any premature or negative conclusions about the quality of Chinese vaccines, five of which are now in final trials. It has also been suggested that SinoPharm and Sinovac should also file registrations with the US Food and Drug Administration and the European Union to enhance transparency and build trust in the West. 

Currently, only Pfizer and BioNTech have published, on December 10,huge chunks of finalized data about the final trials of their messenger ribonucleic acid vaccine. 

A masked child takes a look at Sinovac’s vaccine products at a trade fair in Beijing in September. Photo: AFP

A recent press release from Sinovac noted that its entire research and development process as well as trials at home and abroad, like those in Brazil, had conformed to international standards. It said it had “rich experience and credentials” in supplying vaccines to overseas clients, and that one hepatitis A vaccine produced by the company had been included in the WHO’s list of pre-approved drugs for worldwide immunization.        

The fact that Hong Kong and Singapore have joined Brazil with plans to procure Sinovac’s vaccine will also boost adoption across Asia and other similar, densely populated counties in the developed world. About one million doses are primed for Hong Kong by early January, but the city’s government also noted it must review data from Sinovac before granting approval.

Singapore’s Lianhe Zaobao newspaper noted in an op-ed that once the Lion City starts using the Chinese product after stringent review and assessment, other ASEAN nations will be convinced of the quality and place orders as well.  

Both Hong Kong and Singapore, nonetheless, have also struck purchase deals with Pfizer and AstraZeneca. 

In China, some cities and provinces have since October begun to give shots to priority and vulnerable groups with Sinovac’s vaccine. 

Transport and storage guidelines issued by Shanghai’s Center for Disease Control and Prevention viewed by Asia Times note that attenuated vaccines like the one from Sinovac should be “moderately refrigerated” at 2-8 degrees Celsius all the way from the production line to a place of inoculation, adding that all existing cold-chain trucks will only need simple modifications to enhance container airtightness and disinfection before they can be used to distribute the vaccine. Such vaccines do not need to be diluted before administration. 

By comparison, Pfizer’s mRNA vaccine is more expensive and complex to ship and store. It must be chilled at 70 degrees below freezing and defrosted to 2-8 degrees before each injection. Moderna’s vaccine must be kept at -20 degrees.

An epidemiologist with Shanghai’s CDC told Asia Times that Sinovac’s vaccine was tailor-made for the developing world where infrastructure could not support advanced cold-chain transport. 

“Efficacy-wise, attenuated vaccines can protect against Covid for about half a year thus multiple shots are needed to maximize the effect. Pfizer claims its product can be 95% effective but the biggest draw of Sinovac’s vaccine is it is simple and cheap to manufacture and ship, so people in rural China and in other developing countries will have easier access,” said the export.

“What is needed to distribute is trucks with ordinary refrigerators.” 

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