Expert urges Covid-19 autumn booster expansion amid waning immunity

A testing expert has urged the government to offer the Covid-19 autumn top-up vaccine to all UK adults, and start the programme for over 50s as soon as possible, because antibody levels are falling – potentially meaning more people could become ill with the virus over the winter months.

Last month the Joint Committee on Vaccination and Immunisation published its final recommendations for this autumn’s Covid booster jab programme. Those eligible for a further dose included all adults aged over 50, all people in a clinical risk group, pregnant women, staff working in adult care homes, frontline health and social care workers, and household contacts of people with immunosupression.

However, the latest Covid antibody figures from the Office for National Statistics show that the number of people in England with a higher level of antibodies (800 ng/ml) has fallen swiftly, from a peak of 82.4% of the population in March to 71.9% in mid-July.

Similar levels of antibody decline have been modelled for Scotland, Wales and Northern Ireland.

Dr Quinton Fivelman, chief scientific officer at medical testing provider London Medical Laboratory, said that the drop was concerning as the population needed to retain a substantial number of antibodies going into the winter months, particularly with the more contagious Omicron BA.4 and BA.5 sub-variants in circulation. He called for the government to offer more adults access to booster jabs.

“The simple truth is that, if this rate of decline continues to accelerate and the first UK adults don’t start receiving their boosters until October, only 60% of the population will retain substantial antibodies by the time they are jabbed,” he said.

“Almost all scientists and doctors agree that the higher the level of antibodies you have, the more you are protected against catching the virus and particularly, in developing a severe illness.

“One developing concern is that the new Omicron BA.4 and BA.5 sub-variants do not produce as high an immune response as the previous strains, so re-infection is more likely to occur. Higher levels of antibodies are important to neutralise the virus, stopping infection and limiting people transmitting the virus to others.”

However, Fivelman noted that most people will have the baseline antibody level of at least 179ng/ml. The ONS figures for England showed that 96.3% had at least this baseline level in mid-July.