AUTHOR=Peano Alberto , Politano Gianfranco , Gianino Maria Michela 

TITLE=Determinants of COVID-19 vaccination worldwide: WORLDCOV, a retrospective observational study

JOURNAL=Frontiers in Public Health

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2023.1128612

DOI=10.3389/fpubh.2023.1128612

ISSN=2296-2565

ABSTRACT=Introduction
The COVID-19 pandemic has resulted in numerous deaths, great suffering and significant changes in people's lives worldwide. The introduction of the vaccines was a light in the darkness, but after 18 months, a great disparity in vaccination coverage between countries has been observed. Since disparities in vaccination coverage have become a global public health issue, this work aims to analyse several variables to identify possible determinants of COVID-19 vaccination.
Methods
An ecological study was conducted using pooled secondary data sourced from institutional sites. Two hundred-five countries and territories worldwide were included. Sixteen variables from different fields were considered to establish possible determinants of COVID-19 vaccination: sociodemographic, cultural, infrastructural, economic, and political variables and health system performance indicators. The percentage of the population vaccinated with at least one dose and the total doses administered per 100 residents on 15 June 2022 were identified as indicators of vaccine coverage and outcomes. Raw and adjusted values for delivered vaccine doses in the multivariate GLM were determined using R. The tested hypothesis (i.e., variables as determinants of COVID-19 vaccination) was formulated before data collection. The study protocol was registered (NCT05471635).
Results
GDP per capita (Odds = 1.401 [1.299-1.511] C.I. 95%), access to electricity (odds = 1.625 [1.559-1.694] C.I. 95%), political stability, absence of violence/terrorism (Odds = 1.334 [1.284-1.387] C.I. 95%) and civil liberties (odds = 0.888 [0.863-0.914] C.I. 95%) were strong determinants of COVID-19 vaccination. Several other variables displayed a statistically significant association with outcomes, although the associations were stronger for total doses administered per 100 residents. There was substantial overlap between raw outcomes and their adjusted counterparts.
Discussion
This pioneering study is the first to analyse the association between several different categories of indicators and COVID-19 vaccination coverage in a wide complex setting, identifying strong determinants of vaccination coverage. Political decision-makers should consider these findings when organising mass vaccination campaigns in a pandemic context to reduce inequalities between nations and achieve a common good from a public health perspective.