A new analysis published late last week in Vaccine concludes that COVID-19 vaccination averted 12,806 COVID-19 deaths among Belgians aged 65 years and older from 2021 through 2023. Vaccines have been available to Belgians in that age-group since January 2021.
That represents a 54% reduction in mortality, which was seen across subgroups broken down by age, including Belgians 65 to 79 years and those 80 years and older. From January 2021 and January 2023, a total of 11,033 COVID-19 deaths were reported through the national epidemiologic surveillance system among the population aged 65 years and older in Belgium, the authors said.
The authors estimated deaths averted by taking into account the vaccine efficacy (VE) for each variant of concern (VOC) during the 2-year study period, and matching that information with national data on vaccine coverage and the number of reported COVID-19 deaths from the epidemiological surveillance over time.
Biggest impact during Delta
Overall, vaccines averted the highest rate of deaths during the period dominated by the Delta variant, with 68% of deaths averted. Vaccines averted only 31% of deaths during the Alpha period and 54% of deaths during Omicron.
During the Alpha period, VE 0 to 59 days after vaccination was estimated at 81.9 % (95% confidence interval [CI], 78.1% to 85.1 %) for those aged 65 to 79 years and at 74.7 % (95% CI, 71.2 % to 77.7 %) for those aged 80 years and older. VE was 90.5% and 91.4% for those 65 to 79 and 80 and older, respectively, during Delta, the authors said.
"We observed a weekly waning rate in VE estimates of on average 1.2 % for the entire study period, and more specifically of −0.6 %, 1.0 %, and 2.2 % within the Alpha, Delta, and Omicron periods, respectively," they wrote.
In calculating averted deaths, the authors estimated 4,952 deaths (39%) were averted among those aged 65 to 79 years, and 7,853 (61%) among those aged 80 years and older.
Our analyses revealed a higher impact of COVID-19 vaccination on reducing mortality during the Delta and Omicron period
"Our analyses revealed a higher impact of COVID-19 vaccination on reducing mortality during the Delta and Omicron periods," the authors concluded. "The vaccination campaign was still being rolled out during the Alpha period, resulting in a higher vaccine coverage during Delta and Omicron periods. VE against mortality waned more rapidly during the Omicron period than during Delta, consistent with other reports."
