Risk of SARS-CoV-2 infection and subsequent hospital admission and death at different time intervals since first dose of COVID-19 vaccine administration, Italy, 27 December 2020 to mid-April 2021

Alberto Mateo-Urdiales; Stefania Spila Alegiani; Massimo Fabiani; Patrizio Pezzotti; Antonietta Filia; Marco Massari; Flavia Riccardo; Marco Tallon; Valeria Proietti; Martina Del Manso; Maria Puopolo; Matteo Spuri; Cristina Morciano; Fortunato Paolo D'Ancona; Roberto Da Cas; Serena Battilomo; Antonino Bella; Francesca Menniti-Ippolito; Italian Integrated Surveillance of COVID-19 study group; on behalf of the Italian COVID-19 vaccines registry

doi:10.2807/1560-7917.ES.2021.26.25.2100507

Risk of SARS-CoV-2 infection and subsequent hospital admission and death at different time intervals since first dose of COVID-19 vaccine administration, Italy, 27 December 2020 to mid-April 2021

Euro Surveill. 2021 Jun;26(25):2100507. doi: 10.2807/1560-7917.ES.2021.26.25.2100507.

Authors

Alberto Mateo-Urdiales^{1

2}, Stefania Spila Alegiani³, Massimo Fabiani¹, Patrizio Pezzotti¹, Antonietta Filia¹, Marco Massari³, Flavia Riccardo¹, Marco Tallon⁴, Valeria Proietti⁵, Martina Del Manso^{1

2}, Maria Puopolo⁶, Matteo Spuri¹, Cristina Morciano⁷, Fortunato Paolo D'Ancona¹, Roberto Da Cas³, Serena Battilomo⁵, Antonino Bella¹, Francesca Menniti-Ippolito³; Italian Integrated Surveillance of COVID-19 study group⁸; on behalf of the Italian COVID-19 vaccines registry⁸

Affiliations

¹ Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy.
² European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
³ National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy.
⁴ Department of Informatics, Istituto Superiore di Sanità, Rome, Italy.
⁵ DG-SISS, Ministero della Salute, Rome, Italy.
⁶ Department of Neuroscience, Istituto Superiore di Sanità, Rome, Italy.
⁷ Research Coordination and Support Service, Istituto Superiore di Sanità, Rome, Italy.
⁸ The members have been listed at the end of this article.

PMID: 34169819
PMCID: PMC8229378
DOI: 10.2807/1560-7917.ES.2021.26.25.2100507

Abstract

To assess the real-world impact of vaccines on COVID-19 related outcomes, we analysed data from over 7 million recipients of at least one COVID-19 vaccine dose in Italy. Taking 0-14 days post-first dose as reference, the SARS-CoV-2 infection risk subsequently decreased, reaching a reduction by 78% (incidence rate ratios (IRR): 0.22; 95% CI: 0.21-0.24) 43-49 days post-first dose. Similarly, hospitalisation and death risks decreased, with 89% (IRR: 0.11; 95% CI: 0.09-0.15) and 93% (IRR: 0.07; 95% CI: 0.04-0.11) reductions 36-42 days post-first dose. Our results support ongoing vaccination campaigns.

Keywords: COVID-19; Italy; pandemic; vaccination.

MeSH terms

COVID-19 Vaccines
COVID-19*
Hospitalization
Hospitals
Humans
Italy / epidemiology
SARS-CoV-2
Vaccines*

Substances

COVID-19 Vaccines
Vaccines