Scientists find how immune system reacts to Covid variants

Body's natural immune response following Covid infection is sustained for up to seven months, but these antibodies are not sufficient against contemporary variants of the virus, finds a study suggesting the importance of vaccines against the infectious disease.

The study, published in the PLOS Medicine, also stressed on the need to invest in new vaccine designs to keep pace with emerging Covid variants.

Researchers analysed the serum of 233 individuals diagnosed with Covid-19 over seven months and found that the level of immunity over time is dependent on disease severity and the viral variant.

Further, the antibodies developed during the first wave also had reduced effectiveness against six variants, ranging from those observed in the second wave in Australia through to three variants of concern that have driven the global pandemic in the UK, Brazil and South Africa.

"We can learn a great deal from these people who were infected in the first wave in Australia as they were infected with the same variant that our current vaccines are based on," said Fabienne Brilot, Associate Professor at the University of Sydney.