A study by the British government has found that both the Pfizer-BioNtech and Oxford-AstraZeneca vaccines are highly effective in reducing COVID-19 infections among people aged 80 years and older.

According to Public Health England(PHE) on Monday, three to four weeks after the first shot, a single dose of either vaccine was more than 80 percent effective at preventing hospitalization.

In the case of the Pfizer-BioNtech vaccine, there is evidence suggesting it leads to an 83-percent reduction in deaths from COVID-19.

For seniors aged 70 or older, protection against symptomatic COVID-19  
ranged between 57 and 61 percent for one dose of Pfizer and between 60 and 73 percent for the Oxford-AstraZeneca vaccine.

Assessing that the latest study adds to growing evidence that the vaccines are working to reduce infections and save lives, Dr. Mary Ramsay, the head of immunization at the PHE, cautioned that the degree of their effectiveness remains unknown.

The study comes after a number of countries, including France and Germany, initially decided not to immunize their elderly citizens aged 65 or older with the AstraZeneca vaccine due to concerns over its efficacy among seniors.