COVID infection: Signs you have a weak immune system | The Times of India

As per the data obtained from WHO reports, most of the people who contracted the novel coronavirus in 2020 developed antibodies 1-3 weeks after the symptoms started to show. “Patients who have had more severe disease appear to have higher levels of

important neutralizing antibodies. Patients who had mild or asymptomatic COVID-19 have low levels of neutralizing antibodies (or even undetectable levels). In these persons it is possible the innate immune response and the T cell response cleared the virus,” the report says.

Usually a person who has been recovered from a viral infection is protected against another new infection if there are sufficient antibodies. However, changes in the virus sequence can make the immunity less effective.

So far, 5 strains of coronavirus have been placed in the variants of concern category. A number of recombinant strains have also come to the fore.