The analysis, published by the Office for National Statistics (ONS), uses blood-test data collected during the Coronavirus (COVID-19) Infection Survey to test for antibodies. It excludes infections reported in hospitals and care homes.
In England, antibodies were found in 1 in 8 people; in Wales in 1 in 10; in Scotland in 1 in 11; and in Northern Ireland in 1 in 13 people.
According to the ONS report, it takes two to three weeks for the body to produce enough antibodies to combat the Chinese Communist Party (CCP) virus, commonly called the novel coronavirus.
“Once a person recovers, antibodies remain in the blood at low levels, although these levels can decline over time to the point that tests can no longer detect them,” the ONS report states.
The study shows that infections are much more widespread than previously thought, according to Lawrence Young, virologist and professor of molecular oncology at Warwick Medical School.
“Measuring antibodies in the blood is an indication of previous infection but doesn’t indicate when that infection took place,” he said in a statement.
“The implications are that infection rates increased significantly between November and December,” Young added. “This raises some important questions concerning the possible impact of the UK variant virus on infection rates—this variant is more transmissible and may account for the increased levels of infection as detected by antibodies.”
An official study last week showed that natural immunity is comparable to the protection from a vaccine.
The Public Health England (PHE) study of health care workers concluded that having previously had the disease gave people at least 83 percent, but up to 99 percent, immunity. That protection from reinfection would last for a minimum of five months.
“The take-home message from this study is that a primary infection with SARS-CoV-2 provides at least 94 percent protection against symptomatic reinfection for at least 5 months,” Eleanor Riley, professor of immunology and infectious disease at the University of Edinburgh, said in a statement.
“This suggests that natural infection provides short term protection against COVID-19 that is very similar to that conferred by vaccination.”
Infection rates in England peaked at the start of January, when over 1 in 50 people had the virus, but have been falling since.
However, along with hospitalisations, CCP virus deaths—which lag behind infections by around three weeks—appear to still be rising.
Currently, the daily death rate (an average taken over seven days) stands at 1,128—higher than the 942 reached in the spring peak in 2020.
Mary Clark contributed to this report.