Direct and Indirect Effectiveness of mRNA Vaccination against Severe Acute Respiratory Syndrome Coronavirus 2 in Long-Term Care Facilities, Spain

We conducted a registries-based cohort study of long-term care facility residents >65 years of age offered vaccination against severe acute respiratory syndrome coronavirus 2 before March 10, 2021, in Spain. Risk for infection in vaccinated and nonvaccinated persons was compared with risk in the...

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Bibliographic Details
Authors: Monge, Susana, Olmedo, Carmen, Alejos, Belén, Lapeña, María Fé, Sierra, María José, Limia, Aurora, COVID-19 Registries Study Group2, Mazagatos, Clara, Larrauri, Amparo
Format: article
Publication Date:2021
Country:España
Institution:Instituto de Salud Carlos III (ISCIII)
Repository:Repisalud
Language:English
OAI Identifier:oai:repisalud.isciii.es:20.500.12105/15459
Online Access:http://hdl.handle.net/20.500.12105/15459
Access Level:Open access
Keyword:COVID-19
SARS-CoV-2
BNT162 Vaccine
COVID-19 Vaccines
Cohort Studies
Humans
Long-Term Care
RNA, Messenger
Spain
Vaccination
Description
Summary:We conducted a registries-based cohort study of long-term care facility residents >65 years of age offered vaccination against severe acute respiratory syndrome coronavirus 2 before March 10, 2021, in Spain. Risk for infection in vaccinated and nonvaccinated persons was compared with risk in the same persons in a period before the vaccination campaign, adjusted by daily-varying incidence and reproduction number. We selected 299,209 persons; 99.0% had >1 dose, 92.6% had 2 doses, and 99.8% of vaccines were Pfizer/BioNTech (BNT162b2). For vaccinated persons with no previous infection, vaccine effectiveness was 81.8% (95% CI 81.0%-82.7%), and 11.6 (95% CI 11.3-11.9) cases were prevented per 10,000 vaccinated/day. In those with previous infection, effectiveness was 56.8% (95% CI 47.1%-67.7%). In nonvaccinated residents with no previous infection, risk decreased by up to 81.4% (95% CI 73.3%-90.3%). Our results confirm vaccine effectiveness in this population and suggest indirect protection in nonvaccinated persons.