New Delhi, July 26 : Vaccines prevented more than 2.5 million deaths from SARS-CoV-2, the virus behind Covid-19 infections, worldwide, according to a study.

The study, led by researchers from the Catholic University of the Sacred Heart in Italy, showed that one Covid death was avoided for every 5,400 doses of vaccine administered.

Some 82 per cent of the lives saved by vaccines involved people vaccinated before encountering the virus, 57 per cent during the Omicron period, and 90 per cent 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), revealed the findings, published in the journal Jama Health Forum.

"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," said the researcher Dr. Angelo Maria Pezzullo, and Dr. Antonio Cristiano from the varsity.

For the study, the experts studied worldwide population data, applying a series of statistical methods to figure out who among the people who became ill with Covid did so either before or after getting vaccinated, before or after the Omicron period, and how many of them died (and at what age).

"We compared this data with the estimated data modeled 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," Dr. Pezzullo explained.

It also turned out that most of the saved years of life (76 per cent) involved people over 60 years of age, but residents in long-term care facilities contributed only 2 per cent of the total number.

Children and adolescents (0.01 per cent of lives saved and 0.1 per cent of life years saved) and young adults aged 20'29 (0.07 per cent of lives saved and 0.3 per cent of life years saved) contributed very little to the total benefit, the researchers said.

/IANS