At least 470,000 people aged 60 and over have been directly saved by the vaccines since the start of their rollout, data from 33 countries suggests.
The latest study by the WHO Regional Office for Europe and European Centre for Disease Prevention and Control, or ECDC, says that the estimate does not include lives saved by vaccinating those younger than 60 years old, nor lives saved from the indirect effect of vaccination because of reduced transmission.
The numbers were calculated by estimating the number of deaths that would have happened had it not been for the vaccines using the actual weekly reported death counts.
The near-half-a-million people figure denotes the difference between those estimates and the number of reported deaths from COVID-19 between December 2020 and November.
The scientists behind the study estimated that COVID-19 vaccination saved 469,186 lives in this age group in the 33 countries during the study period.
More importantly, the data suggests that vaccination has reduced the expected number of deaths by approximately half.
In 30 countries with data also available in smaller age groups, the most significant number of lives saved was among those aged 80 years and over, with an estimated total of 261,421 lives.
Although COVID-19 proved to be devastating in terms of its deadliness, WHO Europe regional director Hans Henri Kluge said that "we can now categorically say that without COVID-19 vaccines as a tool to contain this pandemic, many more people would have died."
"In some countries, the death toll would have been double what it is now without the vaccines. It is therefore critically important that all Member States in the European Region achieve high coverage for people in the at-risk groups as soon as possible," he stated.
"Countries with lower vaccination uptake rates must continue to prioritize those who are at highest risk and protect the vulnerable groups as rapidly as possible."
"But vaccines must be accompanied by a range of preventive measures to keep transmission levels low and keep society open," Kluge explained.
The 33 European countries included in the research reported over 1.5 million confirmed deaths related to COVID-19. 90.2 per cent of the fatalities were people aged 60 years and over.
ECDC director Andrea Ammon said that when fighting against COVID, the impetus should now be on improving low vaccination rates in some countries on the continent.
"[This is] currently being reflected in overloaded health care systems and high mortality rates," she said.
"There are still too many individuals at risk of severe COVID-19 infection whom we need to protect as soon as possible. Even in countries that have achieved good overall vaccination coverage, there are still sub-populations and age groups in which coverage remains lower than desired."
"The vaccination of older age groups must continue to be an urgent priority for saving the most lives in the weeks and months to come, she concluded.
But vaccination is one part of the toolbox of essential measures needed to curb the pandemic, and it won't end the health crisis on its own.
"We know the virus thrives in closed, crowded and confined spaces, and that's why we must also follow measures known to reduce transmission, especially now the colder weather is driving us to gather indoors," WHO's Kluge said.
"Wear a mask in crowded, closed and confined spaces, cover coughs and sneezes, keep physical distance from other people and wash your hands regularly. Ventilation is important too, so if it's safe to do so open a window or a door to let in fresh air."
"By making these actions part of our daily routine, we can all help stop infection and the spread of the virus. In the same way that we routinely put on a seatbelt when driving, we should think to wash our hands, wear a mask, or keep distance from other people, to protect from infection," Kluge concluded.