It has been generally accepted that COVID-19 vaccines were essential for saving lives and limiting the spread of the pandemic. But to what extent? New research provides the answer.
Between 2020 and 2024, COVID-19 vaccines saved 2.5 million lives globally, preventing one death for every 5,400 doses, as calculated by the Universita Cattolica del Sacro Cuore and Stanford University. The findings reveal that most lives were saved before individuals were exposed to the virus, particularly during the Omicron period and among those aged 60 years and older. The researchers also calculated 14.8 million years of life saved, with the elderly gaining the majority of these benefits.
Specifically, the 82% of the lives saved by vaccines involved people vaccinated before encountering the virus, 57% during the Omicron period, and 90% involved people aged 60 years and older. In all, vaccines have saved 14.8 million years of life (one year of life saved for 900 doses of vaccine administered).
Data analysis
To derive this outcome, the researchers spent a period at Stanford Universityaspart of the project “European network staff eXchange for integrAting precision health in the health Care sysTems- ExACT”.This project is funded by the European Research Excellence Programme RISE project-Marie Slodowska Curie and it is coordinated by Professor Stefania Boccia.
The scientists studied worldwide population data, applying a series of statistical methods to determine who among the people who became ill with COVID did either before or after getting vaccinated, before or after Omicron period, and how many of them died (and at what age).
The researchers compared this data with the estimated data modelled in the absence of COVID vaccination and were then able to calculate the numbers of people who were saved by COVID vaccines and the years of life gained as a result of them.
It was futher shown that most of the saved years of life (76%) involved people over 60 years of age, but residents in long-term care facilities contributed only with 2% of the total number. Children and adolescents (0.01% of lives saved and 0.1% of life years saved) and young adults aged 20-29 (0.07% of lives saved and 0.3% of life years saved) contributed very little to the total benefit.
According to Boccia: “Before ours, several studies tried to estimate lives saved by vaccines with different models and in different periods or parts of the world, but this one is the most comprehensive because it is based on worldwide data, it also covers the Omicron period, it also calculates the number of years of life that was saved, and it is based on fewer assumptions about the pandemic trend.”
Thus, these data indicate an important overall benefit from COVID-19 vaccination over the period 2020-2024. The greatest benefits were secured for a portion of the global population who are typically more fragile – the elderly.
The research appears in the journal JAMA Health Forum, titled “Global Estimates of Lives and Life-Years Saved by COVID-19 Vaccination During 2020-2024.”
