Higher COVID-19 Vaccination Rates Are Associated with Lower COVID-19 Mortality: A Global Analysis

Abstract

Mass vaccination initiatives are underway worldwide, and a considerable percentage of the world’s population is now vaccinated. This study examined the association of COVID-19 deaths per 1000 cases with a fully vaccinated population. The global median deaths per 1000 cases were 15.68 (IQR 9.84, 25.87) after 6 months of vaccinations and 11.96 (IQR 6.08, 20.63) after 12 months. Across 164 countries, we found significant variations in vaccination levels of populations, booster doses, and mortality, with higher vaccine coverage and lower mortality in high-income countries. Several regression models were performed to test the association between vaccination and COVID-19 mortality. Control variables were used to account for confounding variables. A 10-percentage-point increase in vaccination was associated with an 18.1% decrease in mortality after 6 months (95%CI, 7.4–28.8%) and a 16.8% decrease after 12 months (95%CI, 6.9–26.7%). A 10-percentage-point increase in booster vaccination rates was associated with a 33.1% decrease in COVID-19 mortality (95%CI, 16.0–50.2%). This relationship is present in most analyses by country income groups with variations in the effect size. Efforts are needed to reduce vaccine hesitancy while ensuring suitable infrastructure and supply to enable all countries to increase their vaccination rates.

Assessing the Influence of COVID-19 Vaccination Coverage on Excess Mortality across 178 Countries: A Cross-Sectional Study

“…These findings suggest that countries with higher vaccination coverage experienced lower mortality rates associated with all causes. Similar findings can be found in previously published analyses [ 9 , 10 ]. However, it is important to consider the limitations of our ecological analysis when interpreting these results.…”

Evolving Patterns of COVID-19 Mortality in US Counties: A Longitudinal Study of Healthcare, Socioeconomic, and Vaccination Associations

“…Notably, the relationship briefly reversed following the Delta surge (lasting for only about 23% and 27% of the weeks for CFR and OMHR, respectively). The observed predominantly negative correlation between vaccination rates and COVID-19 mortality aligns with existing research, strengthening the notion that vaccinations were effective in reducing COVID-19 mortality Hoxha et al (2022). The occasional shifts in associations can be attributed to the rise of new variants, notably the Delta and Omicron variants, as our vaccination dataset includes the initial rounds of vaccinations and does not account for the booster doses.…”

COVID-19 Infection Risk Among Previously Uninfected Adults: Development of a Prognostic Model

“…The objective of our study was to develop an algorithm from a model as a proof-of-concept that given a sufficiently large evidence base a valid prognostic model can be used to inform a simple risk calculator so that clinicians can effectively counsel patients as to their risk with respect to modifiable risk factors. On a cumulative basis, the administration of vaccine doses exceeds 13 billion 1 but the global distribution of those doses is highly variable, 40 leaving large groups of individuals as unvaccinated or partially vaccinated. While the vaccines have been shown to be effective 40 , 41 the antibodies for the Omicron variants can wane substantially over time rendering fully vaccinated and boosted individuals protection against hospitalization and death but vulnerable to asymptomatic and symptomatic infection.…”

“…On a cumulative basis, the administration of vaccine doses exceeds 13 billion 1 but the global distribution of those doses is highly variable, 40 leaving large groups of individuals as unvaccinated or partially vaccinated. While the vaccines have been shown to be effective 40 , 41 the antibodies for the Omicron variants can wane substantially over time rendering fully vaccinated and boosted individuals protection against hospitalization and death but vulnerable to asymptomatic and symptomatic infection. 42 For the groups of currently unvaccinated individuals prognostic models similar to the one presented here have value for the clinician offering counseling regarding modifiable behaviors such as using facemasks, avoiding high-risk situations, working at home, and other nonpharmaceutical behavioral measures.…”