Question to the Department of Health and Social Care:

To ask Her Majesty's Government what assessment they have made of evidence that suggests people can be reinfected with COVID-19 more than once; and what estimate they have made of the number of people who have contracted COVID-19 for a second time.

The SARS-CoV-2 Immunity & REinfection EvaluatioN (SIREN) study follows up healthcare workers across the United Kingdom to estimate reinfection risk following a natural infection with SARS-CoV-2. Preliminary results suggest that reinfection is possible, though rare. This is supported by several case reports on reinfection internationally.

Forty four potential cases of reinfections were detected among 6,614 participants who had evidence of a past infection, contributing 1,339,078 days of follow-up. Those who had antibodies upon enrolment had a rate of becoming (re)infected that was 83% lower than that among those who had no antibodies upon enrolment. No estimate has been made of the number of people who have contracted COVID-19 for a second time in the general population.