Clinical Outcomes in Hospitalized Vaccine-Breakthrough Coronavirus Disease 2019 Cases Compared With Contemporary...

Area of Science:

• Immunology
• Infectious Diseases
• Public Health

Background:

• Chile predominantly used the inactivated severe acute respiratory syndrome coronavirus 2 vaccine (CoronaVac) during its prebooster campaign.
• Real-world data on vaccine effectiveness against severe outcomes is crucial for public health strategies.

Purpose of the Study:

• To compare hospitalization outcomes between vaccinated and unvaccinated adults in Chile.
• To assess the effectiveness of CoronaVac in preventing severe disease and death.

Main Methods:

• A comparative study of 206 hospitalized adults who received CoronaVac versus 507 unvaccinated adults.
• Analysis of key outcomes including critical care requirements, mortality, and hospitalization duration.
• Statistical adjustment for age to account for differences between groups.

Main Results:

• Vaccinated individuals were older but required less critical care.
• Adjusted mortality was lower in the vaccinated group compared to the unvaccinated group.
• Hospitalization duration was shorter for vaccinated adults, with the most pronounced benefits observed in those aged 60 years and above.

Conclusions:

• The CoronaVac vaccine demonstrated significant effectiveness in reducing severe outcomes among hospitalized adults in Chile.
• The findings support the use of CoronaVac, particularly for older populations (≥60 years), in mitigating the impact of severe acute respiratory syndrome coronavirus 2.
• Real-world evidence confirms the protective benefits of CoronaVac against severe disease and mortality.