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China’s Sinovac a Near Miss in Immunisation: Offered to Poorer Nations

Sinovac’s COVID-19 vaccine CoronaVac. "A coronavirus vaccine developed by China's Sinovac has been found to be 50.4% effective in Brazilian clinical trials, according to the latest results released by researchers." - BBC News (image:

China’s in house Coronavirus vaccine, Sinovac’s CoronaVac was under the spotlight recently as data from its clinical trials in Brazil showed that it was only 50.38% effective, according to Instituto Butantan, the Brazilian laboratory connected to the Sao Paulo Public health department.
Brazil’s total coronavirus cases have skyrocketed, and the country has now the third highest number worldwide, behind India and the USA. Brazil, one of the developing countries on the World Economic Situation and Prospects 2014 list, was operating clinical trials of CoronaVac alongside a vaccine from AstraZeneca and the University of Oxford.

China’s small data sets

Initial reactions to the CoronaVac trials seemed positive with The Lancet reporting the peer review investigation into the Sinovac Life Sciences vaccine, developed in Beijing, China, in November 2020. What stands out from this review, Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine in healthy adults aged 18–59 years: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trial is the small sample numbers used, which “followed the requirement of the National Medical Products Administration in China—ie, recruitment of at least of 20–30 participants in phase 1 and 500 participants in phase 2.”

The actual number of phase 1 participants was 143 with 600 phase 2 participants. The study was carried out in Jiangsu Provincial Centre for Disease Control and Prevention (CDC) in Suining County, Jiangsu province, China, with an estimated population of 1,450,000 people. The tiny sample size from the Chinese state-backed study is in direct contrast to the 195 participants in phase 1 and 21,999 participants in phase 2 of the comparative Pfizer-BioNTech trials for the UK vaccine.

The Chinese Government has kept a tight grip on what can be reported by its Brazilian partners. This was apparent at a Sao Paolo press conference held in December to enthuse about the success rate of CoronaVac from the Brazilian clinical trial but Beijing’s gagging orders meant that the researchers could only refer to the World Health Organisation (WHO) standard for general use, by saying that the vaccine was more than 50% effective without publishing any other data. This 50% effectiveness standard has also been adopted locally by the Brazilian Health Regulatory Authority Anviva.

Lack of international signoff

The WHO has only allowed five Chinese vaccines approved for export since 2014 and the CoronaVac is not among them. The requirements for the WHO Trial Registration Data Set (TRDS) set out in its published International Standards for Clinical Trial Registries is that it should be meaningful.
To be audited according to WHO standards, clinical trials have three benchmarks: Self-audit, self-reporting and site visits. The WHO team investigating the origin of the virus in Wuhan had difficulties with Beijing putting multiple obstacles in their way to stop them travelling to China to investigate the outbreak of the virus in Wuhan. The trip finally started on 14 January 2021 and ran into further delays. A WHO site visit to audit Sinovac’s clinical findings in Jiangsu remains highly improbable.

Brazil is one of four developing nations conducting clinical trials with Indonesia, Turkey, Chile and the Philippines also testing Sinovac for use at home. Brazil has conducted the largest clinical trial of the Sinovac vaccine with 13,000 participants reporting a 50.38% efficiency, Indonesia says that it is 65.3% effective with 1,600 people, while Turkey has tested 1,322 people with an efficacy rate of 91.25%. Bloomberg reported that the Turkish values were erroneous after the study revealed only 29 participants. The fluctuating rates need further investigation but international scientists voiced concerns at the lack of phase 3 clinical data available for them to review despite the mass roll-out of vaccines.

1.8 million doses were shipped to Brazil for the trial, while Indonesia has been gifted 1.2 million doses of Sinovac “free of charge.” Dr Peter Hotez, professor and Dean of the National School of Tropical Medicine at Baylor College of Medicine in the US described the move as “vaccine diplomacy” and that “it was important the World Health Organisation signed off on Chinese vaccines before widespread distribution.” “Doing this ahead of WHO prequalification makes me concerned,” he told ABC News.

Abusing its Alliances

It would appear that China is using its recent donor relationship with GAVI the Vaccine Alliance, as a way to bolster President Xi Jinping’s overseas expansion strategy by offering a low cost solution to the more expensive Pfizer or Moderna mRNA vaccines, at 90% efficacy but requiring refrigeration; options not necessarily available to developing nations.

China’s donation to GAVI between 2016 to 2020, was just USD 5 million, representing only 0.05% of all donations during the same period. Chinese social media platform TikTok used its pledge of USD 10 million for its first donation to encourage vaccine awareness in Africa alongside its expansion plans for Nigeria, Kenya and South Africa with 0.1% of all donations, while the grant making charity vehicle of China Merchants Group, valued at USD 1.3 billion and headquartered in Hong Kong pledged USD 1.5 million or 0.01% of all donations. The UK Government on the other hand gave USD 2,624.2 billion or 25.8% of all donations between 2016 to 2020.

By doing “global public good”, Xi Jinping is courting the poorer nations in an apparent noble gesture but, buyer beware. The ancient Chinese saying tells us that, a bad beginning makes a bad ending (不善始者不善终). The Sinovac vaccine uses inactivated virus cells and The U.S. Department of Health and Human Services (HHS) website states that “It is well known that inactivated vaccines usually don’t provide immunity (protection) that’s as strong as live vaccine.”

Where does that leave Hong Kong?

Hong Kongers are concerned with the lack of transparency over Brazil’s clinical trial effectiveness and lack of reporting of the phase 3 data for peer scrutiny and WHO approval.
In December, citizens were told they could choose from three different vaccine manufacturers, including Pfizer-BioNTec, Astra Zenica and Sinovac Biotech Ltd. The issues in Hong Kong with the imposition of the National Security Law by China that bans protests amongst other crackdown measures looks ready to be challenged once more as people react with distrust to the news of Sinovac’s inclusion on the government procurement list.

Civil Service Secretary Patrick Nip promised to strictly review all vaccines procured by Hong Kong to placate concerns.

The Economic Letter 2019/02 from the Office of the Government Economist of the Hong Kong Special Administrative Region of the time stated that “Hong Kong’s present stage of population ageing is similar to that in the UK.” Over the previous three decades, the number of elders aged 65 plus in Hong Kong has increased by the equivalent of 276%.

The Sinovac clinical trials in Jiangsu left out people over 60 years old. The median age of the phase 1 clinical trials was 40 years old. The median age of the phase 2 clinical trials was 45 years old. These subjects were healthy. Further, the study concentrated heavily on cataloguing side effects from the injection.

Age may shed light on the low results achieved by the Brazilian phase 3 trial, which studied “Healthcare professionals who work in direct contact care of people with possible or confirmed COVID-19 cases” and “Adults (18-59 years) and Elderly (60 years and above).”

The Sinovac researchers themselves described the limitations of their study that included “Lack of data on immune persistence.” Hence, it will be impossible to quantify how long any potential immunity provided by the Coronavac injection lasts for and how many booster shots will be needed to build up immunity over time. An attractive initial low cost for the vaccine will be impractical to sustain in the long term for developing nations induced to rely on the Chinese Government.

It should raise alarm bells for the authorities

China is no stranger to issues surrounding vaccine manufacturers. In 2017, Chinese children across the mainland were injected with faulty vaccines for diphtheria, tetanus and whooping cough. In 2018, its manufacturer, Changchun Changsheng Biotechnology Company later had to pay USD 1.3 billion in fines and its license to produce vaccines revoked, which sent it into bankruptcy for falsifying records for a rabies vaccine produced by the company. A Chinese research article published in ScienceDirect’s Vaccine Journal in August 2019 concluded “that public confidence was significantly affected by the vaccine scandal, particularly for vaccine producers and drug regulators,” and “to build public confidence for vaccination, regulators have to reform regulatory practices and manufacturers have to ensure vaccine quality.”

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