A positive antibody test for SARS-CoV-2 does not necessarily equate to immunity. Standards antibody tests may detect antibodies in the blood that are raised in response to SARS-CoV-2 but are not able to inhibit its replication, and therefore are not protective against future infection.
Our team, in collaboration with Dr Ian Patterson, are using neutralisation assays to detect antibodies that can prevent the replication of SARS-CoV-2. This virus is added to serum samples from patients who have recovered from COVID-19, allowing us to see how effective their antibodies are at neutralising the virus. We are using this approach in combination with a range of other rapid and ELISA-based antibody tests, to assess how well they correlate to a neutralising response, so we can say with certainty if an antibody positive result, will be indicative of protection from further infection, and for how long.