With single-dose COVID-19 vaccines now being rolled out at a new production site launched by CanSino Biologics in Tianjin, the company expects that by next year, it will be capable of providing the world with more than 600 million doses of Convidecia－the only adenovirus vector COVID-19 vaccine that has gained conditional market approval in China so far, the company's CEO said.

"The new COVID-19 vaccine production base can produce about 250 million doses of vaccines annually. It will enable us to deliver quality vaccines to the market more efficiently, and it will also significantly boost our production capacity," said Yu Xuefeng, co-founder and CEO of the company, as vaccines began coming off production lines at the new base on Sunday.

According to interim analysis of late-stage human trials, the vaccine, called Ad5-nCoV, is 65.3 percent effective in preventing symptomatic cases after 28 days of injection and 90.1 percent effective in preventing severe cases, the company said.

On Feb 25, the Chinese National Medical Products Administration granted conditional market approval to the vaccine after it was approved by the Central Military Commission for emergency use in June. The development of the vaccine kicked off on Jan 20 last year when the COVID-19 epidemic situation was grave in China.

By working with its partners, the company's annual domestic production for COVID-19 vaccines is capable of reaching 700 million doses. CanSino Biologics is also developing vaccines for children between age 6 and 18, the company said in a report in March.

Chen Wei, a key figure behind the vaccine and a researcher at the Institute of Military Medicine of the Academy of Military Sciences, said the new production base can help China contribute more to the world's fight against the COVID-19 pandemic.

"We are also working on developing COVID-19 vaccines administered through inhalation," she said on Sunday.

Yu, the CEO, said an inhaled vaccine can activate antibodies in the airways and offer extra protection. In the event that the extra layer of protection fails, other parts of the immune system could still act against it. The inhaled COVID-19 vaccine was approved for clinical trials on March 22.

Unlike other vaccines approved for conditional market use in China, Convidecia doesn't have an age restriction, typically between 18 and 59, because older people have been taking part in its clinical trials. Some of them have been older than 90, Chen added.

Convidecia uses a genetically modified adenovirus－a common type of virus－to carry an antigen from the novel coronavirus into cells to induce an immune response. Its clinical trials were conducted in Pakistan, Mexico, Russia, Chile and Argentina. No severe complications related to the vaccine have been reported so far, the company said.