Vaccination Hesitancy among Health-Care-Workers in Academic Hospitals Is Associated with a 12-Fold Increase in the Risk of COVID-19 Infection: A Nine-Month Greek Cohort Study
Fotinie Ntziora,
Evangelia Georgia Kostaki,
Ioannis Grigoropoulos,
Amalia Karapanou,
Ismini Kliani,
Maria Mylona,
Alexa Thomollari,
Sotirios Tsiodras,
Theoklis Zaoutis,
Dimitrios Paraskevis,
Nikolaos V. Sipsas,
Anastasia Antoniadou,
Petros P. Sfikakis
Affiliations
Fotinie Ntziora
1st Department of Propaedeutic Internal Medicine, University General Hospital Laiko, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Evangelia Georgia Kostaki
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Ioannis Grigoropoulos
4th Department of Internal Medicine, University General Hospital Attikon, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
Amalia Karapanou
1st Department of Propaedeutic Internal Medicine, University General Hospital Laiko, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Ismini Kliani
4th Department of Internal Medicine, University General Hospital Attikon, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
Maria Mylona
1st Department of Propaedeutic Internal Medicine, University General Hospital Laiko, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Alexa Thomollari
4th Department of Internal Medicine, University General Hospital Attikon, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
Sotirios Tsiodras
4th Department of Internal Medicine, University General Hospital Attikon, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
Theoklis Zaoutis
National Public Health Organization, 15123 Athens, Greece
Dimitrios Paraskevis
Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Nikolaos V. Sipsas
Pathophysiology Department, University General Hospital Laiko, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Anastasia Antoniadou
4th Department of Internal Medicine, University General Hospital Attikon, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
Petros P. Sfikakis
1st Department of Propaedeutic Internal Medicine, University General Hospital Laiko, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
Health-Care-Workers (HCWs) are considered at high risk for SARS-CoV-2 infection. We sought to compare rates and severity of Coronavirus disease 2019 (COVID-19) among vaccinated and unvaccinated HCWs conducting a retrospective cohort study in two tertiary Academic Hospitals, namely Laiko and Attikon, in Athens, Greece. Vaccinated by BNT162b2 Pfizer-BioNTech COVID-19 mRNA vaccine and unvaccinated HCWs were included and data were collected between 1 January 2021 and 15 September 2021. Overall, 2921 of 3219 HCWs without a history of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection were fully vaccinated during the study period (90.7% at each Hospital). Demographic characteristics were comparable between 102/2921 (3.5%) vaccinated and 88/298 (29.5%) unvaccinated HCWs with COVID-19, although age and occupation differed significantly. None were in need of hospital admission in the vaccinated Group, whereas in the unvaccinated Group 4/88 (4.5%) were hospitalized and one (1.1%) died. Multivariable logistic regression analysis revealed that lack of vaccination was an independent risk factor for COVID-19 with an odds ratio 11.54 (95% CI: 10.75–12.40). Vaccination hesitancy among HCWs resulted to highly increased COVID-19 rates; almost one in three unvaccinated HCWs was SARS-CoV-2 infected during the 9-month period. The absolute need of vaccination of HCWs, including boosting dose, is highlighted. Evidence should be used appropriately to overcome any hesitancy.
