Public Health England reveals an estimated three-quarters of people in the UK between the ages of 75 and 80 have antibodies against COVID-19.
Public Health England (PHE) has published new findings showing that an estimated 75.8% of those in the 70 to 84 age bracket, who donated blood, had antibodies against COVID-19 by early March 2021. It says that only 5.6% were from natural infection, showing that older adults are able to mount a robust immune response to a single dose of the COVID-19 vaccines.
It also found that, in the population as a whole, 37.7% of people had antibodies either from infection or vaccination.
Testing for antibodies
To estimate the proportion of the population with antibodies to COVID-19, tests for COVID-19 antibodies are taken routinely from blood samples across the country which are provided to PHE from NHS Blood and Transplant.
This study used two different tests to measure two different kinds of antibodies: ones that are naturally produced after infection and ones that develop in response to the vaccine.
The study found that the proportion of over 70s with vaccine antibodies started to increase from early January.
Conversely, the proportion with antibodies resulting from natural infection started to plateau at the same time, suggesting that the vaccine is preventing older people from getting COVID-19.
Dr Gayatri Amirthalingam, Consultant Epidemiologist at PHE, said: “Vaccines are the way out of this pandemic and provide the best protection from COVID-19, especially in those with the highest risk. These data show that the COVID-19 immunisation programme is having a big impact on the number of older people that have antibodies after vaccination.
“This suggests that a single dose of vaccine is producing a good immune response in those most at-risk and there is good indication that it is also reducing infection rates.”
The group with the highest proportion of antibodies after natural infection is 16 to 29-year-olds, indicating ongoing infection and transmission in younger people.
The latest vaccine effectiveness data show that in those aged over 70, both the Pfizer-BioNTech and Oxford-AstraZeneca vaccines reduce the risk of getting symptomatic disease by around 60% after a single dose, and in those over 80, protection against hospitalisation is around 80%. The data also show that the Pfizer-BioNTech vaccine is 85% effective at stopping people aged over 80 from dying from COVID-19.
Dr Mary Ramsay, Head of Immunisation at PHE, said: “We published our first data on how well these vaccines are working in the real world around a month ago. Many millions more people have since been vaccinated and we now have even more confidence in the vaccines.
“The latest data continue to show that both vaccines in use in the UK are still providing really good levels of protection against COVID-19. As well as reducing cases, if vaccinated people catch COVID-19, they are less likely to get a serious illness and die.”
