It comes from the latest study by experts from the Universities of Glasgow and Birmingham
Two in five people who have impaired immune systems have a “low or undetectable” antibody response after being double vaccinated, a new study suggests.
While the vaccines appear to be active among all adults, the researchers said their data supports a third coronavirus vaccine among groups who had absent or lower level antibody responses.
Vaccination experts are expected to make a recommendation on whether a booster campaign is necessary in the autumn imminently.
The finding comes as weekly Covid-19 deaths are at the highest number since March.
Data from the Office for National Statistics (ONS) show that there were 571 deaths registered in England and Wales in the week ending August 13 mentioned Covid-19 on the death certificate, up 8% on the previous week.
In the latest study, experts from the Universities of Glasgow and Birmingham compared the immune responses between 600 patients with immune-mediated inflammatory diseases, such as those with cancer, inflammatory arthritis, diseases of the kidney or liver, or patients who are having a stem cell transplant, and 231 healthy individuals after they had received both doses of either the AstraZeneca or Pfizer Covid-19 vaccines.
They performed immune tests on blood samples and examined not only antibody levels in the blood but also the ability of a particular form of white blood cell, called a T cell, to respond to the vaccine.
Around three in five people in the vulnerable groups were found to have an antibody response similar to those found in healthy adults.
But 40% of generated a low antibody response compared to healthy people, according to the study which has been published as a pre-print by The Lancet.
Published: by Radio NewsHub