Can you be re-infected with the new variant if you have already had COVID-19 from one of the older variants?
People who have recovered from SARS-CoV-2 infection are usually protected from being infected a second time (called re-infection). This is because they develop neutralizing antibodies that remain in their blood for at least 5-6 months, maybe longer. These antibodies bind to specific parts of the spike protein that have mutated in the new variant (K417N and E484K). We now know that these mutations have allowed the virus to become resistant to antibody neutralization.
The blood samples from half the people we tested showed that all neutralizing activity was lost. This suggests that they may no longer be protected from re-infection. In the other half, the levels of antibodies were reduced and so the risk of re-infection is not known. It is therefore important that people who have previously had COVID-19 continue to adhere to public health measures. Protecting ourselves through masks, regular washing or sanitising of hands, cleaning of surfaces, and social distancing remain the best defense against all SARS-CoV-2 viruses, including the new lineage.