This paper responds to a request for advice on the evidence for whether reinfection with SARS-CoV-2 is possible, and whether there is any emerging risk that not all patients develop immunity once they clear the virus.
- Anecdotal reports of patients who have recovered from COVID-19 becoming reinfected may be due to testing problems. While we cannot say for certain that reinfection is not possible, the evidence for reinfection is so far not compelling.
- Overall, based on the changes detected in the blood cells and antibodies seen in most recovered patients, it could be reasonably extrapolated that individuals would be protected from reinfection with the same strain, at least in the short to medium term. However, no direct evidence for immunity in patients exists at present.
- Population-level studies would be needed to determine with greater certainty whether reinfection can occur in people who have developed antibodies to SARS-CoV-2.
- A decline in immunity or mutations in the virus could result in a future scenario in which reinfection is possible.