1 in 7 people in England have Covid-19 antibodies either after infection or vaccination

Around 14 per cent (one in seven) of people in England now have antibodies against Covid-19, according to a recent study.

The findings of the study were published in the journal BMJ.

The fifth round of the Real-time assessment of community transmission (React-2) study, led by Imperial College London, used the Fortress lateral flow test to detect antibodies in a drop of blood from the finger.

The researchers then sent the tests to a random sample of the population between January 26 and February 8, 2021 and 154,172 people in England had valid results.

The authors of the study mentioned that this round of the study included—for the first time—18,000 people who had received at least one dose of a coronavirus vaccine.

The study further found an uneven distribution of SARS-CoV-2 antibodies in the population, with rates highest in London at 16.9 per cent. There was also a higher burden in key workers and some minority ethnic groups, similar to the pattern in the first wave.

The prevalence of antibodies in unvaccinated people was higher in people of black (22.4 per cent) and Asian (20.0 per cent) ethnicity compared to 8.5 per cent in white people.

Among unvaccinated people, the highest prevalence of antibodies was found in care home workers at 24.2 per cent and healthcare workers at 21.9 per cent.

The survey also found that those in frontline jobs such as police officers and teachers were more likely to test positive (around 11 per cent) than non-key workers (7.8 per cent).

Pfizer vaccine efficacy

The researchers also examined the antibody response in 12,820 people who had received at least one dose of the Pfizer BioNTech vaccine more than 21 days previously.

They found that two doses of vaccine, or a single dose following previous infection, confers high levels of antibody response across all age groups. Overall, 91 per cent had antibodies after two doses of vaccine, rising to 95.5 per cent in people under 60. In those over 80, the figure was slightly lower at 88 per cent.

During a Science Media Center briefing, Paul Elliot, director of the React program and chair in epidemiology and public health medicine at Imperial College London, said: “Overall, regardless of age, we are seeing very high antibody positivity rates from two doses of the Pfizer vaccine and from one dose plus natural infection.”