Samples of the COVID-19 inactivated vaccine are seen at a vaccine production plant of China National Pharmaceutical Group (Sinopharm) in Beijing, capital of China, April 10, 2020. Photo:Xinhua

China's first COVID-19 vaccine development lab and the only vaccine producing department at P3 level in Central China were completed in Wuhan, Hubei Province, on Wednesday, with the ability to produce about 100 million doses of vaccine per year.

The lab and the producing department are under the China National Pharmaceutical Group (Sinopharm) and China National Biotec Group (CNBG).

The group previously announced that two COVID-19 vaccine candidates they developed - one by CNBG Beijing institute and another by CNBG Wuhan institute - have passed phase two clinical trials and they are cooperating with authorities in the United Arab Emirates to start Phase three clinical trials for inactivated vaccine candidates they developed.

The completion of the lab and the production department is a bonus for mass production of COVID-19 vaccines, Cao Guangjing, deputy-provincial governor of Hubei, said at the ceremony for the completion on Wednesday.

The construction started in March, according to the group.

Another CNBG production department in Beijing has also been completed and can produce about 120 million doses of vaccine per year, according to the group.

Some netizens have expressed concern about whether 120 million doses per year could meet the global demand, as China has promised to provide COVID-19 vaccines as a public good when available.

An immunology expert in Beijing told the Global Times on Wednesday on condition of anonymity that the potential vaccines, when available, would be first provided to people with high infection risk and to residents in areas with infection outbreaks.

"Massive vaccination would not be launched immediately, so 120 million doses per year would possibly be enough," the expert said.

He tried to ease the concerns saying that even though massive vaccination is needed, he believed CNBG could rapidly expand production lines as they have mature technology to produce inactivated vaccines.

He also said that Chinese companies may allow foreign partners to produce the COVID-19 vaccines, when available, in their own countries if this is allowed in their cooperation contracts.

Some experts previously reached by the Global Times estimated that CNBG's COVID-19 vaccine could be available this August if the phase three trials go smoothly. But the anonymous expert estimated that the phase three clinical trials would take at least 1-1.5 years to confirm the safety and efficacy of the vaccine candidate.

China is developing COVID-19 vaccines in five categories - inactivated vaccines, recombinant protein vaccines, live attenuated influenza vaccines, adenovirus vaccines and nucleic acid-based vaccines, reports said.

Except for live attenuated influenza vaccines, products of the other four types have reportedly entered human clinical trials.

Several other types of vaccines, if developed successfully, are theoretically more effective than inactivated vaccines, according to experts.

Chinese biopharmaceutical firm CanSino Biologics Inc announced on Monday that a recombinant novel coronavirus vaccine (Ad5-nCoV) the company developed with a military research team has received special one-year military drug approval.

In 2017, a vaccine producing base in which CanSino invested 450 million yuan was completed in Tianjin. The base can produce 70 million doses of vaccine per year, according to media reports.