Covid-19: This human molecule is helping coronavirus escape antibodies

New Delhi - The SARS-CoV-2 spike protein strongly binds to biliverdin, a molecule which was giving these proteins an unusual green colouration.

A natural molecule called biliverdin present in human body is helping SARS-CoV-2, the virus that causes Covid-19, escape antibodies - a discovery that can help explain why some Covid patients become severely ill despite having high levels of antibodies against the virus, report researchers.

When SARS-CoV-2 infects a patient's lungs, it damages blood vessels and causes a rise in the number of immune cells.

"Both of these effects may contribute to increasing the levels of biliverdin and bilirubin in the surrounding tissues. And with more of these molecules available, the virus has more opportunity to hide from certain antibodies," said Annachiara Rosa, first study author at the Francis Crick Institute in the UK.

"This is a really striking process, as the virus may be benefiting from a side-effect of the damage it has already caused," Rosa said in the paper published in the journal Science Advances.

In their research, teams from the Francis Crick Institute, in collaboration with researchers at Imperial College London, Kings College London and UCL (University College London), found that biliverdin and bilirubin, natural molecules present in the body, can suppress the binding of antibodies to the coronavirus spike.

As vaccines are rolled out globally, understanding immunity to SARS-CoV-2 and also how the virus evades antibodies is critically important.

The ability of the immune system to control the infection and the quality of the antibody response are highly variable, and not well correlated, between individuals.