Chinese CoronaVac remains promising in global vaccine race

China has been one of the fore runners in Covid-19 vaccine race with two promising candidates - Sinovac and Sinopharm - , of whom Sinovac's CoronaVac is likely to be at best chances of getting approved and distributed internationally because of its trail data made available.

Earlier in August 2020, Bangladesh approved chinese company Sinovac Biotech' human trial in the country but later it got cancelled as the government denied to co-fund the domestic trials of the vaccine.

However, countries like Indonesia, Turkey, Brazil and Chile have announced their purchase of the Sinovac vaccine.

In early December of 2020,  the first batch of Sinovac vaccines (1.2 million doses ) arrived in Indonesia in preparation for a mass vaccination campaign, with another 1.8m doses due to arrive by January 2021.

Earlier in December 2020, Turkish Health Minister Fahrettin Koca said the country had signed a contract to buy 50 million doses of the Covid-19 vaccine from Chinese company Sinovac, Global Times reported. 

The first batch of 20 million doses of Sinovac vaccines will be received in December and January. The second batch of 10 million doses will arrive in February. Turkey is open to procuring vaccines from other companies after February, Koca said, according to Anadolu Agency.

Moreover, Sinovac is holding talks with the Philippines for a potential sale while Singapore said it had signed advance purchase agreements with several vaccine makers, including Sinovac.

In Europe, Hungarian Foreign Minister Peter Szijjarto said on Facebook that the country would seek emergency domestic approval of a Chinese Covid-19 vaccine rather than waiting for a review by the EU's European Medicines Agency. He said the safety of the vaccine is not a "political or ideological question, but a professional one."

Sinovac has been conducting large-scale clinical trials in Brazil that is expected to release clinical data from its CoronaVac candidate in Brazil soon. However, the death of a phase 3 trial participant in October led Brazilian authorities to temporarily halt the Sinovac trial. Although details of the death were unclear, the trial was quickly resumed with the Brazilian institute involved in the trial confirming the participant's death was unrelated to the vaccine.

CoronaVac is one of three experimental Covid-19 vaccines China has been using to inoculate around one million people under an emergency-use programme.

Despite not knowing the results of phase 3 trials, a condition typically required to receive regulatory approval, CoronaVac has been approved for emergency use in China to vaccinate high-risk groups since July 2020.

This emergency approval is likely to have followed positive data from the vaccine's phase 1 and 2 trials.

Beijing-based biopharmaceutical company Sinovac's Covid vaccine is called CoronaVac, an inactivated vaccine, which works by using killed viral particles to expose the body's immune system to the virus without risking a serious disease response.  

"CoronaVac is a more traditional method that is successfully used in many well-known vaccines like rabies," Associate Prof Luo Dahai of the Nanyang Technological University told the BBC.

One of Sinovac's main advantages is that it can be stored in a standard refrigerator at 2-8 degrees Celsius, like the Oxford vaccine, which is made from a genetically engineered virus that causes the common cold in chimpanzees. Moderna's vaccine, on the other hand, needs to be stored at -20C and Pfizer's vaccine at -70C.

It means that both Sinovac and the Oxford-AstraZeneca vaccine are a lot more useful to developing countries which might not be able to store large amounts of vaccine at such low temperatures.

Sinovac has reached its' phase 3 trial after it published the results of its phase 2 trial in mid- November of 2020 suggesting that CoronaVac induced immune responses among volunteers and may offer Covid-19 protection.

China National Biotec Group Company Limited (CNBG), formerly the Central Epidemic Prevention Department of Beiyang Government, announced that Sinovac's production capacity is estimated to reach 1 billion vaccines in 2021 in its newly built 20,000 sq m production plant.

Sinovac, in a separate statement, said that it would be able to manufacture 300 million vaccine doses annually and aims to complete construction of a second production facility by the end of 2020 to increase annual Covid-19 vaccine production capacity to 600 million doses, Al Jazeera reported.

China's other Covid-19 vaccines, developed by China National Biotec Group (CNBG) under the China National Pharmaceutical Group (Sinopharm), have been approved by the United Arab Emirates and Bahrain.