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. 2022 Dec 23;11(1):31.
doi: 10.3390/vaccines11010031.

COVID-19 Vaccination Did Not Increase the Risk of Potentially Related Serious Adverse Events: 18-Month Cohort Study in an Italian Province

Maria Elena Flacco  1 , Cecilia Acuti Martellucci  1 , Graziella Soldato  2 , Giuseppe Di Martino  2 , Roberto Carota  2 , Marco De Benedictis  2 , Graziano Di Marco  2 , Giustino Parruti  2 , Rossano Di Luzio  2 , Antonio Caponetti  2 , Lamberto Manzoli  3
Affiliations

COVID-19 Vaccination Did Not Increase the Risk of Potentially Related Serious Adverse Events: 18-Month Cohort Study in an Italian Province

Maria Elena Flacco et al. Vaccines (Basel). .

Abstract

This cohort study on the entire population of an Italian Province assessed the incidence of potentially vaccine-related serious adverse events (PVR-SAEs) by COVID-19 vaccination status. From January 2021 to July 2022, we extracted all deaths and hospitalizations due to several cardiovascular diseases, pulmonary embolism, and deep vein thrombosis from National Healthcare System official data. During the follow-up, 5743 individuals died, and 2097 were hospitalized for PVR-SAEs. Vaccinated subjects (n = 259,821) did not show an increased risk of all-cause death, non-COVID death, or any PVR-SAEs, as compared to the unvaccinated (n = 56,494). These results were consistent across genders, age-classes, vaccine types, and SARS-CoV-2 infection status and did not vary in Cox models adjusting for age, gender, SARS-CoV-2 infection, and selected comorbidities. In the infected population, any dose of vaccine was associated with a lower likelihood of death and PVR-SAE. In the uninfected population, subjects who received one or two doses showed a significantly higher incidence of most outcomes, likely due to a large selection bias introduced by the Italian restriction policies targeting uninfected subjects who received less than three doses. In conclusion, COVID-19 vaccination was not associated with an increase of mortality or selected PVR-SAEs incidence. Further research is warranted to evaluate the long-term safety of COVID-19 vaccines.

Keywords: COVID-19; Italy; SARS-CoV-2; adverse events; cohort study.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Flowchart of study participants.
Figure 2
Figure 2
Kaplan-Meier estimates of time to death by vaccination status (at least one dose of COVID-19 vaccines vs. unvaccinated).
Figure 3
Figure 3
Cumulative proportion of the deaths by follow-up time. Figure 3A (top): among unvaccinated subjects; Figure 3B (bottom) among partially vaccinated subjects (those who received a single COVID-19 vaccine dose).
See this image and copyright information in PMC

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