Chinese Covid vaccine safe in phase 1 & 2 trials, generates antibodies, Lancet says

The vaccine, BBIBP-CorV, includes the killed virus mixed with another component, aluminium hydroxide, which is an adjuvant as it is known to boost immune responses.

A Sinovac Biotech LTD vaccine candidate for coronavirus on display at the China International Fair for Trade in Services in Beijing (representational image) | Noel Celis | AFP/Getty Images via Bloomberg

New Delhi: A Covid-19 vaccine developed by a Chinese company, based on an inactivated SARS-CoV-2 virus, has been proven to be safe and effective in phase 1 and 2 trials, The Lancet reported Friday.

“The inactivated SARS-CoV-2 vaccine, BBIBP-CorV, is safe and well-tolerated at all tested doses in two age groups,” the researchers from the Beijing Institute of Biological Products Company Limited reported in The Lancet Infectious Diseases.

“Humoral responses against SARS-CoV-2 were induced in all vaccine recipients on day 42. Two-dose immunisation with 4 mg vaccine on days 0 and 21 or days 0 and 28 achieved higher neutralising antibody titres than the single 8 mg dose or 4 mg dose on days 0 and 14,” they added.

In immunology parlance, a humoral response means that the vaccine succeeded in eliciting antibodies against the virus.

BBIBP-CorV includes the killed virus mixed with another component, aluminium hydroxide, which is called an adjuvant because it is known to boost immune responses.

It has been developed by the Beijing Institute of Biological Products Company Limited that is affiliated to the state-owned pharma company, Sinopharm. This is one of the five Covid vaccines currently in various stages of development in China. 

Older participants took longer to generate antibodies

The study included participants aged between 18-80 years, though those aged over 60 years were slower to generate an antibody response, sometimes taking upto 42 days to do so.

Younger participants, meanwhile, took 28 days to generate an antibody response. Antibody levels were also lower in those aged between 60-80 years.

Professor Xiaoming Yang, one of the authors of the study, said: “Protecting older people is a key aim of a successful Covid-19 vaccine as this age group is at greater risk of severe illness from the disease.

“However, vaccines are sometimes less effective in this group because the immune system weakens with age. It is, therefore, encouraging to see that BBIBP-CorV induces antibody responses in people aged 60 and older, and we believe this justifies further investigation.” 

The trial was funded by the National Program on Key Research Project of China, National Mega projects of China for Major Infectious Diseases, National Mega Projects of China for New Drug Creation, and Beijing Science and Technology Plan. 

Side-effects

The most common adverse reactions were pain and fever, and were mild to moderate in nature, The Lancet stated.

The researchers wrote in the journal: “In pre-clinical studies, we showed that immunisation with BBIBP-CorV can induce high levels of neutralising antibody titres in mice, rats, guinea pigs, rabbits, and non-human primates (cynomolgus monkeys and rhesus macaques) to provide protection against SARS-CoV-2.”