Vaccination Is Reasonably Effective in Limiting the Spread of COVID-19 Infections, Hospitalizations and Deaths with COVID-19

Abstract

This paper uses large cross-country data for 110 countries to examine the effectiveness of COVID vaccination coverage during the delta variant outbreak. Our results confirm that vaccines are reasonably effective in both limiting the spread of infections and containing more severe disease progression in symptomatic patients. First, the results show that full vaccination rate is consistently negatively correlated with the number of new COVID cases, whereby a 10 percent increase in vaccination rate is associated with a 1.3 to 1.7 percent decrease in new COVID cases. Second, the magnitude of vaccination is shown to contribute significantly to moderating severe disease progression. On average, a 10 percent increase in the rate of vaccination leads to a reduction of about 5 percent in the number of new hospitalizations, 12 percent decrease in the number of new intensive care patients and 2 percent reduction in the number of new deaths. Finally, by comparing the data for the same period between 2020 and 2021, we also check how well vaccination performs as a substitute for lockdowns or other stringent government protection measures. Results suggest that vaccination appears to be an effective substitute for more stringent government safety measures to contain the spread of COVID infections only at a sufficiently high vaccination coverage threshold (more than 70 percent). On the other hand, vaccination is shown to be quite effective in limiting the more severe course of the disease in symptomatic patients already at moderate vaccination coverage (between 40 and 70 percent). This suggests that vaccination can also help to reduce pressure on the health system and thus benefit the overall public health of society. On the other hand, the efficient rollout of vaccines could explain the favourable economic performance in the second half of 2021 despite the severe outbreak of the delta variant.

Role of vaccine in fighting the variants of COVID-19

“…Damijan et al. [45] have proved that vaccines were quite effective in limiting the spread of infection and preventing more serious disease progression in symptomatic patients. Meanwhile, the necessity of COVID-19 vaccination should be adequately disseminated which can increase public acceptance of the vaccine, thereby increasing the vaccination [46] .…”

Clinical Profile, Comorbidities, and Outcome of the Unvaccinated and Hospitalized for COVID-19 in Northern Brazil: Retrospective Cohort

“…This study warns that despite being younger and with fewer comorbidities, COVID-19 has worse outcomes in these cases, increasing the risk of death. Thus, vaccination is the best strategy to reduce hospitalizations and deaths from COVID-19, and effective strategies for vaccine adherence must be developed because the current challenge is the fake news and negationist, political, and even religious positioning [37][38][39].…”

Effectiveness of different booster vaccine combinations against SARS-CoV-2 during a six-month follow-up in Mexico and Argentina

“…The pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) had a profound impact on global health, and an especially greater impact in countries with limited healthcare infrastructure ( 1 , 2 ). Throughout the pandemic, Latin America experienced high mortality rates and a lack of access to adequate health resources, including limited access to vaccines which took the most crucial role in mitigating the spread of disease and its severity ( 3 – 5 ). As for December 2023, Brazil is the Latin American country most affected by the COVID-19 pandemic with a report of 37.5 million cumulative cases, followed by Argentina (10 million) and Mexico (7.7 million) ( 6 ).…”