Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, pursuant to his oral contribution, Official Report, 25 March 2021, Col 1112 in response to the hon Member for Christchurch, on what date the SIREN study from Public Health England began; how many people have participated in that study; and if he will publish the results to date.

Recruitment into the SARS-CoV-2 Immunity and REinfection EvaluatioN (SIREN) study began on 18 June 2020 and finished on 31 March 2021. Over 44,000 participants have enrolled into SIREN during this period from 135 sites across the United Kingdom.

In January 2021 the SIREN team pre-printed the analysis of reinfection rates from the SIREN study up to the end of November 2020. This has since been updated to the beginning of January 2021 and published in a peer-reviewed journal which is available at the following link:

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00675-9/fulltext

In February 2021 the SIREN team pre-printed a second analysis which investigated vaccine coverage and effectiveness of the BNT162b2 vaccine against infection. This is scheduled to be published in a peer reviewed journal in April and is available at the following link:

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3790399

Further analyses are underway. The follow-up period is one year since enrolment for all participants, so the final study results will be available after March 2022.