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Vaccine Effectiveness Against Infection and Death Due to SARS-CoV-2, Following One and Two Doses of the BNT162b2 and ChADox-1 in Residents of Long-Term Care Facilities in England, Using a Time-Varying Proportional Hazards Model

30 Pages Posted: 13 Sep 2021

See all articles by Sathyavani Subbarao

Sathyavani Subbarao

St. George Hospital; Government of the United Kingdom - Immunisation and Countermeasures Division

Andrew Copas

University College London - Institute for Global Health

Nick Andrews

Public Health England Colindale; UK Health Security Agency - COVID-19 Surveillance Cell

Charlotte Gower

Public Health England Colindale

Jamie Lopez Bernal

Public Health England Colindale; UK Health Security Agency - COVID-19 Surveillance Cell

Mary E. Ramsay

Public Health England - Immunisation, Hepatitis, and Blood Safety Department

Karthik Paranthaman

Public Health England - National Infection Service, Field Service

More...

Abstract

Background: We investigated the effect of both doses of either BNT162b2 or ChAdOx-1 vaccine among residents of Long-term care facilities (LTCFs) in England. This cohort is at particularly high risk for severe outcomes related to COVID-19 and is regularly tested regardless of symptoms.

Methods: This observational study uses testing, immunisation and mortality data from 8 December 2020 to 25 June 2021 in LTCF residents aged 65 years and above.   Cox proportional hazards models were used to derive adjusted hazard ratios (aHR) for the risk of infection and death within 28 days of positive test result, adjusted for sex, age-group, previous infection, deprivation, and incidence rate in the local authority area. The impact of interval between first and second dose was also explored.  

Findings: Of 219733 LTCF residents, 41828 (19%) had a positive test and 10719 (4.9%) died within 28 days of a positive test during the study period.  Relative to unvaccinated individuals, aHR for infection were lowest at 0.43 (95% CI 0.35-0.52) 36-49 days after first dose and 0.27 (0.20-0.38) at 29-60 days following second dose . Against death, aHR was lowest at 0.25 (0.20-0.31) 28-56 days after first dose and 0.13 (0-05-0.32) in the 1-14 days after second dose.  As expected, some waning of protection against infection was observed after seven weeks from first dose which persisted to 2-4 weeks following second dose.

Interpretation: Vaccination with one dose of BNT162b2 and ChAdOx-1 provides moderate protection against infection and death in residents in LTCFs. Protection is strong after two doses.

Funding: None to declare.

Declaration of Interest: None to declare.

Ethical Approval: Vaccine effectiveness studies are undertaken by Public Health England as part of ongoing surveillance activities and did not require ethical approval.

Keywords: COVID-19, SARS-CoV-2, long term care facilities, elderly, care homes, immunosenescence.

Suggested Citation

Subbarao, Sathyavani and Subbarao, Sathyavani and Copas, Andrew and Andrews, Nick and Gower, Charlotte and Bernal, Jamie Lopez and Ramsay, Mary E. and Paranthaman, Karthik, Vaccine Effectiveness Against Infection and Death Due to SARS-CoV-2, Following One and Two Doses of the BNT162b2 and ChADox-1 in Residents of Long-Term Care Facilities in England, Using a Time-Varying Proportional Hazards Model. Available at SSRN: https://ssrn.com/abstract=3922678 or http://dx.doi.org/10.2139/ssrn.3922678

Sathyavani Subbarao (Contact Author)

St. George Hospital

Hamburg
Germany

Government of the United Kingdom - Immunisation and Countermeasures Division ( email )

United Kingdom

Andrew Copas

University College London - Institute for Global Health

United Kingdom

Nick Andrews

Public Health England Colindale ( email )

Wellington House
133-155 Waterloo Road
London, SE1 8UG
United Kingdom

UK Health Security Agency - COVID-19 Surveillance Cell ( email )

United Kingdom

Charlotte Gower

Public Health England Colindale

61 Colindale Avenue
London, NW9 5EQ
United Kingdom

Jamie Lopez Bernal

Public Health England Colindale ( email )

Wellington House
133-155 Waterloo Road
London, SE1 8UG
United Kingdom

UK Health Security Agency - COVID-19 Surveillance Cell ( email )

United Kingdom

Mary E. Ramsay

Public Health England - Immunisation, Hepatitis, and Blood Safety Department ( email )

United Kingdom

Karthik Paranthaman

Public Health England - National Infection Service, Field Service ( email )