A potential Covid-19 vaccine being developed by China National Biotech Group (CNBG) unit Beijing Institute of Biologic Products demonstrated to be safe and triggered immune responses in a combined early and mid-stage test in humans, according to researchers.

Dubbed BBIBP-CorV, the vaccine is already approved for an emergency inoculation programme in China targeting essential workers and others at high infection risk.

According to the World Health Organization (WHO), BBIBP-CorV is one of at least ten coronavirus vaccine programmes progressed to Phase III trials worldwide, with four among these led by Chinese scientists.

The dose-escalation, randomised, double-blind, placebo-controlled, Phase I / II trial of BBIBP-CorV enrolled over 600 healthy participants aged between 18 and 80 years.

The Covid-19 vaccine trial was conducted between 29 April and 30 July in a single centre in China.

Data from the trials showed that giving two injections of BBIBP-CorV at three different doses was safe and well-tolerated in all participants.

Throughout the trial, a robust humoral immune response was observed in all vaccine recipients.

In participants aged 60 and above, antibody levels were lower and took longer to increase significantly than those in younger recipients.

The results do not prove the vaccine is efficacious, a paper published in the medical journal the Lancet showed.

No severe side effects were observed but common mild or moderate adverse reactions such as fever and pain in injection sites were noted.

The study claimed no notable changes in lymphocyte subset or cytokines. The Phase III trials of BBIBP-CorV are progressing outside china.

Aside from this study, state-owned China National Pharmaceutical Group (Sinopharm) unit CNBG has a similar candidate, which is in Phase III trials outside China and used in the country’s emergency use programme.

This investigational candidate induced antibodies without developing serious side effects in early and mid-stage trials.