The Covid-19 vaccination programme has led to “a high proportion of individuals” in England having detectable antibodies, but concerns remain over lower uptake among people who have been previously infected with coronavirus, according to scientists tracking the epidemic.
A study commissioned by the Government found that antibody prevalence in England was 61%, based on self-testing finger prick test results from than 200,000 people, taken between between May 12 and May 25.
But the experts warned that there were some key groups with a lower prevalence of antibodies – particularly unvaccinated younger people, certain minority ethnic groups, those living in deprived areas, and workers in some public facing employment such as hospitality and retail.
Their findings also showed an almost 40% lower vaccine uptake amongst people who reported a previous Covid-19 infection.
Helen Ward, professor of public health at Imperial College London, said: “There are a number of people who have said that they are happy with natural immunity (from Covid-19 infection).
“So I think that we have to put the right messages out there to say, ‘Actually, we know that immunity following infection does wane over time’.”
The researchers said it means that over time, this group will become susceptible to a second infection – unless they are vaccinated.
Data from Imperial College London’s React-2 study, which is yet to be peer-reviewed, showed antibodies were 30% less likely to be detected in men than women, and were higher in people of Asian, black, mixed and other ethnicities compared with white ethnicity.
The presence of coronavirus antibodies suggests someone has had the infection in the past or has been vaccinated.
It takes between two and three weeks after infection or vaccination for the body to make enough antibodies to fight the virus.
Prof Ward said: “We found higher vaccine uptake in people of Asian than white ethnicity (13%), which is a change from what other people have been reported earlier on in the vaccination programme, but still, a much lower coverage in people of black than white ethnicity (59%).”
Prof Ward said healthcare workers were 10 times more likely, and care workers were four times more likely, to have been vaccinated when compared to non-key workers.
She added: “We also found that in some other public-facing occupations such as hospitality and retail, there was 20% lower coverage of vaccine.”
The researchers said they also found the antibody response from a single dose of the Pzifer/BioNTech or Oxford/AstraZeneca vaccines was lower in older age groups but was nearer 100% after the second dose.
Graham Cooke, professor of infectious diseases at Imperial College London, said: “This is particularly important at the moment because we know with delta variants circulating and cases in the community rising, both the main vaccines – Pfizer and AstraZeneca – require those secondary sources to neutralise those viruses effectively.
“So to get that full optimal neutralising dose against the delta variant, you do need your secondary doses.”
Commenting on the findings, Professor James Naismith, director of the Rosalind Franklin Institute, who was not involved in the study, said the data indicates people who identify as having black ethnicity have lower rates of vaccination and higher rates of infection – a “message that should trouble the conscience of this country”.
He said: “This is a very large discrepancy.
“I am not qualified to comment on the reasons for it, but I can say that this means this community is at significantly more risk from the current Covid-19 wave.”
Prof Naismith added: “Current approaches are not working well enough for this community.
“People from all ethnicities in the most deprived quintile also have lower vaccination rates and higher infection rates.
“We need to do better for our fellow citizens.”