The Omicron-specific vaccine candidate developed by Chinese vaccines manufacturer, Sinopharm, can trigger high levels of neutralizing antibodies specifically against the variant while enhancing protection against other main strains by two to three times, scientists from Sinopharm's subsidiary, China National Biotec Group (CNBG), revealed at a press conference on Wednesday.

Zhang Yuntao, one of CNBG's chief scientists, made the remarks at the press conference after one of the company's Omicron-specific inactivated vaccine candidate was approved for clinical trials in the Chinese mainland on Tuesday.

On April 13, two of the group's Omicron-specific inactivated vaccine candidates were already approved for clinical trials in China's Hong Kong Special Administrative Region.

"The clinical trials in the mainland and in Hong Kong could take an estimated three to four months," Zhang said at a press conference on Wednesday.

In previous announcement of approval of the clinical trials, CNBG said that the tests will be conducted on people aged 18 and above with two or three shots of vaccines to evaluate the safety and immunogenicity of the Omicron-specific candidate.

At the press conference on Wednesday, Zhang said the trials will also be conducted on another group of people who had not accepted any vaccine to test immunogenicity and safety on the group.

Cross neutralization tests in vitro showed that the CNBG's Omicron-specific candidate can trigger very high levels of neutralizing antibodies against the Omicron variant, Zhang said, noting that pre-clinical trials showed that the candidate shot is effective on the Omicron variant and its sublineages.

The candidate shots could also enhance neutralizing antibodies against the original strain of the virus and the Delta and Beta variants by two to three times, Zhang noted.

Zhang noted that research and study on Omicron-specific vaccine does not mean denying the original vaccine. "It is still effective to take the original vaccine. This was proved in Hong Kong as it showed that inactivated vaccines are still effective in protecting people, especially those aged 60 and above, from severe disease and deaths."

Recent outbreaks in China showed that many infections caused by Omicron were asymptomatic or with mild illness. Some people hesitate to get vaccinated thinking it is unnecessary. However, Zhang said that, on the contrary, vaccination is still necessary under this circumstance as it can largely help prevent infection and disease.

Yang Huichuan, chief scientist from the CNBG, said during the press conference that the CNBG had built six manufacturing plants and three laboratories with protection level III. If the Omicron candidate vaccine succeeds at last, the CNBG will devote most manufacturing facilities to its production.

CNBG's inactivated vaccines have been registered or used in 119 countries, regions and international organizations and the group has provided more than 3 billion shots to the world, Yang Xiaoming, chairman of CNBG, said at the press conference.

Yang noted that the group achieved production capacity of 10 billion per year for vaccines based on various technologies, including a recombinant candidate and a mRNA candidate.

According to Zhang, CNBG also submitted the application for clinical trial to the national health authorities for the recombinant candidate and the mRNA candidate shots.