Beijing: One of China’s leading COVID-19 vaccine candidates, called ‘BBIBP-CorV’, was shown to be safe. The COVID-19 vaccine elicited immune response in a small early-phase human trial, researchers said Friday. A previous clinical trial reported similar results for a different vaccine that is also based on inactivated whole SARS-CoV-2 virus, but in that study the vaccine was only tested in people aged under 60 years. The latest study, published has been published in the ‘The Lancet Infectious Diseases’ journal. It said the vaccine included participants aged between 18 and 80 years. It found antibody responses were induced in all recipients.
Participants aged 60 and over were slower to respond, taking 42 days before antibodies were detected in all recipients compared with 28 days for participants aged 18-59, the researchers said. Antibody levels were also lower in those aged 60-80 years compared with those aged 18-59, they said.
The ‘BBIBP-CorV’ vaccine used in the study is based on a sample of the virus that was isolated from a patient in China. Stocks of the virus were grown in the lab using cell lines. Then the virus was inactivated using a chemical called beta-proprionolactone.
‘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.
The trial was not designed to assess efficacy of the vaccine, so it is not possible to say whether the antibody responses induced by the vaccine, called BBIBP-CorV, are sufficient to protect from SARS-CoV-2 infection, according to the researchers.
“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,” said Professor Xiaoming Yang, one of the authors of the study, from the ‘Beijing Institute of Biological Products Company Limited’.
“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,” Yang added.
There are currently 42 vaccines for COVID-19 in clinical trials, the researchers noted. These vary in type and include DNA plasmid vaccines, inactivated virus vaccines, adenovirus-vectored vaccines, RNA vaccines, protein subunit vaccines and virus-like particle vaccines, they said.