HONG KONG – China National Biotec Group (CNBG) said that BBIBP-CorV, one of the two COVID-19 vaccines it currently has under development, provides 79.34% protection against the coronavirus.

Volunteers who received the vaccine in the phase III experiment, which is being developed by CNBG’s subsidiary Beijing Institute of Biological Products Co. Ltd., produced high-tier antibodies, with a neutralizing antibody positive conversion rate of 99.52% after two doses, the company said. CNBG is a subsidiary of China National Pharmaceutical Group Corp. (Sinopharm).

The 79.34% rate meets the requirements set by the World Health Organization (WHO) as well as China’s National Medical Products Administration’s (NMPA) minimum standard of 50% efficacy set for approval of COVID-19 vaccines, although the NMPA advised in August that the efficacy rate should be above 70%.

In comparison, Biontech SE and Pfizer Inc.’s vaccine BNT-162b2 has shown 95% efficacy and Moderna Inc. reported 94.1% efficacy for its mRNA-1273 vaccine. Both of these are mRNA vaccines.

However, Frank Luo, associate director of business development at Astrazeneca plc, told BioWorld that the gap may not be an issue: "80% and 90% efficacy rates are no big difference... If I had to get vaccinated, I'd choose CNBG's vaccine. An inactivated vaccine is theoretically safer, and it is expected that its efficacy would be lower anyway.”

CNBG has yet to provide more details on the data. The company initiated phase III trials in the United Arab Emirates (UAE), Peru, Bahrain, Egypt, Jordan and Argentina, involving 69,000 volunteers with 125 nationalities. UAE authorities said earlier this month that BBIBP-CorV was 86% effective, according to phase III data from 31,000 volunteers. It is not yet clear how the company determined the 79.34% efficacy rate.

That said, the data have paved the way for CNBG to officially file for conditional approval from the NMPA. The regulators accepted CNBG’s NDA for the vaccine on Dec. 24. and are expected to grant approval.

"When Chinese companies report their data, and if safe and efficacious, when NMPA issues an approval these will be important additions in the global fight against COVID-19. Getting WHO approval will be a critical next step and I hope that the companies are already working with WHO on the submission of their data for review,” Jerome Kim, the South Korea-based director general at the International Vaccine Institute (IVI), told BioWorld.

The company declined to be interviewed.

Earlier data were positive

CNBG unveiled early animal data of BBIBP-CorV in a paper published in Cell in August, saying that “BBIBP-CorV induces high levels of neutralizing antibodies titers in animal models” and “seems to be safe in animals."

Results from preclinical studies showed that a two-dose immunization using 2 mg/dose of BBIBP-CorV provided protection against SARS-CoV-2 intratracheal challenge in rhesus macaques, without detectable antibody dependent enhancement of infection. In addition, BBIBP-CorV exhibits efficient productivity and good genetic stability for vaccine manufacture.

The study was followed by a randomized, double-blind, placebo-controlled, phase I/II trial that took place in China’s Henan province that involved 640 participants, the results of which were published in The Lancet Infectious Diseases on Oct 15.

Results showed that BBIBP-CorV is safe and well-tolerated at all tested doses in two age groups, ages 18 to 59 or 60 and older. Humoral responses against SARS-CoV-2 were induced in all vaccine recipients on day 42. Two-dose immunization with 4 μg vaccine on days 0 and 21 or days 0 and 28 achieved higher neutralizing antibody titers than the single 8 μg dose or 4 μg dose on days 0 and 14. All vaccine recipients seroconverted and the adverse event profile was mild.

CNBG was one of the first companies worldwide to begin human testing on its COVID-19 experimental shots in April 2020.

While mRNA vaccines have shown higher efficacy rates, inactivated vaccines have the advantage that they do not need to be stored at extremely cold temperatures, meaning easier storage and distribution as well as lower cost. Many believe this could be advantageous for developing countries, to which China has vowed to offer help.

CNBG currently has vaccine supply agreements with Malaysia, Brazil, Pakistan and the UAE, fewer than other developers such as Astrazeneca, Pfizer and Biontech.

CNBG has another COVID-19 vaccine candidate developed by its subsidiary Wuhan Institute of Biological Products. An interim analysis of randomized phase I/II trials for the inactivated SARS-CoV-2 vaccine candidate was published in the Journal of the American Medical Association (JAMA) in August 2020.

The data showed that the vaccine demonstrated immunogenicity and had a low rate of adverse reactions in the 96-subject phase I trial and 224-subject phase II trial and gave the company’s plans to produce 220 million doses annually a boost.

Also from China, Sinovac Biotech Ltd. has a COVID-19 candidate undergoing phase III trials in multiple countries. The company has delayed releasing phase III trial data of its inactivated vaccine candidate this month while it is being on track to win approval in Brazil.