Coronavirus: How effective are the Chinese vaccines? | Science| In-depth reporting on science and technology | DW | 01.02.2021
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Coronavirus: How effective are the Chinese vaccines?

Some countries have already approved vaccines from China or are currently participating in trials. But how effective and safe are the vaccines?

A staff member inspects syringes of COVID-19 inactivated vaccine products at a packaging plant of the Beijing Biological Products Institute Co., Ltd, a unit of state-owned Sinopharm in Beijing.

Chinese-made vaccines are already in use in several countries

Three vaccines are currently far along in development in China. They are the vaccines from the companies Sinopharm, Sinovac Biotech and CanSino.

Only partial data on the efficacy of the vaccines has been released from their respective phase II and III trials. Sinopharm was the first company to officially announce data at the turn of 2020.

The situation is also still unclear with regard to approval of the vaccines. More than a million people have already been vaccinated with Sinopharm's vaccine, but this was done either as part of studies or with emergency approval.

Vaccine nationalism — the other way around

Meanwhile, correspondents in China for Germany's public broadcaster ARD and the daily newspaper FAZ  report on a campaign currently underway in Chinese state media questioning the efficacy and safety of vaccines approved in Western countries.

One accusation is that Western media are concealing the dangers of BioNTech-Pfizer's vaccine.  A prominent presenter on the state-controlled broadcaster joined in these accusations on Twitter. 

Paradoxically, China is actually procuring vaccines from BioNTech-Pfizer  via the company Fosun Pharma. There are many indications that the Chinese government is using this media campaign to deflect criticism over the lack of transparency about its own vaccine manufacturers, possibly because its own development is not delivering the desired results. 

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The data on vaccines from China so far tend to indicate somewhat lower efficacy than their Western competitors. Here is an overview of the vaccines,  where they are already being used, and what is known about their efficacy.

Sinopharm

The vaccine called Vero is based on an inactivated virus. The company Sinopharm developed it in collaboration with the Wuhan Institute of Virology and the Institute of Biological Products. Such vaccines — also called inactivated vaccines — have been tried and tested for decades. For example, they are successfully used against diphtheria, hepatitis B, polio, whooping cough and tetanus.

Phase III trials for Vero have been conducted in 10 countries worldwide,  including the United Arab Emirates, Bahrain, Peru, Morocco, Argentina, Jordan and Pakistan. Test in Serbia were planned, but not implemented. One reason for the research outside the People's Republic is that in China, case numbers dropped so sharply in the summer due to the strict lockdown that it was difficult to obtain any meaningful data at all. 

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So far, Vero is the only Chinese vaccine for which the manufacturer has published official data. On December 29, 2020, Sinopharm reported 79% efficacy in an interim evaluation. The vaccine was licensed in China one day later.

Data from other countries does not present a consistent picture — the Emirates confirmed even higher efficacy in their study: 86%.

The authorities there were even quicker to approve the vaccine than the Chinese.  The vaccine was allowed to be administered from  the beginning of December. Serbia also approved the vaccine in January.

Things were less promising in Peru. Authorities there halted clinical trials in December after one patient suffered paralysis in his arms as a result of vaccination. 

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Sinovac Biotech

The vaccine, called CoronaVac, is also based on inactivated viruses. It has been tested in various phase III trials since the summer, including in Brazil (which approved the vaccine on January 19), Indonesia, Bangladesh and Turkey. The manufacturer has not released official figures on the efficacy of the CoronaVac vaccine, but evaluations by the Brazilian collaborators suggest an efficacy of up to 78%.  Indonesian health authorities report an efficacy of about 65%. 

Although this means that the vaccine is not as effective as the mRNA vaccines approved for use in Europe and the US, it does reach and exceed values that are common for influenza vaccines. Some of these are only 30-60% effective.

Potentially interested countries like Malaysia  and Singapore  are still hesitant. Thailand  plans to introduce the vaccine despite its moderate efficacy. In China, the vaccine has received emergency approval.

Sinovac hopes to increase efficacy by prolonging the interval between doses.  However, further studies are needed before this can happen. Prolonging the time between the first vaccination and the booster shot also increases the risk of mutations occurring.   

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CanSino Biologics

The vaccine called Ad5-nCoV or Convidecia, which the company CanSino Biologics developed together with the Beijing Institute of Biotechnology, is a vector virus vaccine based on an adenovirus type 5.

This means that a harmless transport virus brings non-replicable surface proteins of the SARS-CoV-2 pathogen to the cells and triggers the immune reaction there. In terms of its mode of action, the vaccine is comparable to the British-Swedish vaccine developed by AstraZeneca and the University of Oxford. 

Phase III trials have started in Pakistan, Russia, Mexico and Chile.  A study is also planned in Saudi Arabia. 

In Canada, however, a trial was cancelled because China had not delivered the vaccine doses as agreed to its partner, the Canadian Center for Vaccinology in Halifax. It is possible that one reason for the failure of the envisaged collaboration is a diplomatic dispute between the People's Republic and Canada, which remains unresolved. However, none of the partners involved have commented on the matter.

In China, the vaccine has been administered to military personnel since June 2020. The manufacturer has not yet released efficacy data. 

This article has been updated on February 1, 2021

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