COVID-19 vaccination associated with the hospitalizations and deaths among COVID-19 cases, Azerbaijan, 2021
One of the main goals of COVID-19 vaccination is to reduce occurrence of severe disease and death. COVID-19 vaccination was introduced in Azerbaijan in 2021. We assessed the association of COVID-19 vaccination with hospitalizations and deaths among COVID-19 confirmed cases in Azerbaijan in 2021.
We conducted a cross-sectional COVID-19 data analysis using the national database of polymerase chain reaction (PCR) positive cases in 2021. Only overnight hospital stays were considered as hospitalized cases. COVID-19 deaths were those resulting from COVID-19 related complications within a month of PCR confirmation. Fully vaccinated persons were those who received 2 doses of any COVID-19 vaccine and were confirmed COVID-19 positive at least 2-weeks after vaccination. Partially vaccinated persons who received 1 dose of the vaccine or were confirmed positive within 2-weeks after vaccination with 2 doses and; unvaccinated persons did not receive any dose. Crude risk ratios (RR) were calculated to measure the differences in hospitalizations and deaths among the 3 groups, using unvaccinated as the reference group.
In 2021, a total of 398,233 confirmed COVID-19 cases were reported in Azerbaijan. Of these, 15,461 were hospitalized and 9,099 died. At the time when they were confirmed COVID-19 positive, 120,926 (30%) were fully vaccinated, 46,220 (12%) were partially vaccinated, and 231,087 (58%) were unvaccinated. Fully (RR=0.52 [95% CI=0.50–0.53]) and partially (RR=0.78 [95% CI=0.74–0.82]) vaccinated groups were associated with fewer hospitalizations compared to the unvaccinated group. Similarly, fully (RR=0.32 [95% CI=0.30–0.34]), partially (RR=0.55 [95% CI=0.51–0.60]) vaccinated groups were associated with fewer deaths compared to the unvaccinated group.
Fully and partially vaccinated persons had lower risk of hospitalizations (48% and 22%, respectively) and deaths (68% and 45%, respectively), compared to unvaccinated persons. This study showed the importance of COVID-19 vaccination in reducing hospitalizations and deaths in Azerbaijan, highlighting the need to continue efforts to improve vaccination.