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. 2021 Nov:112:81-88.
doi: 10.1016/j.ijid.2021.09.022. Epub 2021 Sep 15.

Impact of scaling up SARS-CoV-2 vaccination on COVID-19 hospitalizations in Spain

Ignacio Barandalla  1 , Carmen Alvarez  1 , Pablo Barreiro  2 , Carmen de Mendoza  3 , Rubén González-Crespo  4 , Vicente Soriano  5
Affiliations

Impact of scaling up SARS-CoV-2 vaccination on COVID-19 hospitalizations in Spain

Ignacio Barandalla et al. Int J Infect Dis. 2021 Nov.

Abstract

Background: The advent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines has been associated with a significant decline in coronavirus disease 2019 (COVID-19) hospitalizations and deaths. However, little is known about the benefits experienced by different population groups and/or using distinct vaccines.

Methods: The Spanish public registry was analyzed to examine associations between weekly vaccination scale-up and the incidence of COVID-19 hospitalizations by age, sex, and vaccine modality. The study period extended from January 2020 to June 2021.

Results: A total of 363 960 COVID-19 hospitalizations were recorded in Spain during the study period, with three peaks in March 2020, November 2020, and January 2021. The incidence of COVID-19 hospitalizations per 100 000 population increased exponentially with age, on average 71.5% for each decade older. Overall, individuals older than 60 years of age accounted for 65% of all COVID-19 hospitalizations. The speedy vaccination rollout since the end of 2020, with prioritization of the elderly groups, resulted in a rapid fall in COVID-19 hospitalizations starting in February 2021. The benefit was already noticed 3-4 weeks after the first dose, regardless of the vaccine modality.

Conclusions: COVID-19 hospitalizations increased exponentially with age in all three peaks of SARS-CoV-2 infection in Spain. Early mass vaccination of people over 60 years of age prevented a fourth wave of COVID-19 hospitalizations during the spring of 2021.

Keywords: Hospitalizations; Severe COVID-19; Spain; Vaccine.

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Figures

Figure 1
Figure 1
Incidence of COVID-19 hospitalization by age in Spain. Real numbers (continuous line) versus estimated numbers in the exponential model (dotted line).
Figure 2
Figure 2
Incidence of COVID-19 hospitalizations (per 100 000 population) by age group and calendar week.
Figure 3
Figure 3
Impact of COVID-19 hospitalizations in Spain by calendar week and age starting in February 2021.
Figure 4
Figure 4
Scale-up of SARS-CoV-2 vaccination in Spain.
Figure 5
Figure 5
COVID-19 hospitalizations by age group and calendar week starting in January 2021. Real numbers (continuous line) versus estimated numbers without vaccination (dotted line); logarithmic scale.
Figure 6
Figure 6
Decline in the incidence of COVID-19 hospitalizations alongside vaccine scaling up for distinct age groups.
See this image and copyright information in PMC

References

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