LONDON (Reuters) – Almost all people previously infected with COVID-19 have high levels of antibodies for at least six months, which are likely to protect them from reinfection with the disease, the results of a major UK study showed on Wednesday.
The scientists said the study, which measured levels of previous COVID-19 infection in UK populations and how long antibodies persisted in those infected, should provide some assurance that rapid reinfection cases will be rare. .
“The vast majority of people retain detectable antibodies for at least six months after coronavirus infection,” said Naomi Allen, a professor and chief scientist at Britain’s Biobank, where the study was conducted.
Among participants who tested positive for previous COVID-19 infection, 99% retained antibodies to SARS-CoV-2 for three months, the results showed. After the full six months of follow-up, 88% still had them.
Although we cannot be sure about this immunity, the results suggest that people may be protected from further infection for at least six months after the natural infection, Allen said.
She said the findings are also consistent with the results of other studies in the United Kingdom and Iceland, which found that antibodies to coronavirus tended to persist for several months in those who had the disease and recovered.
A study by health workers in the UK, published last month, found that people who had COVID-19 could be protected for at least five months, but noted that those with antibodies could still carry and spread the virus. .
The UK Biobank study also found that the proportion of the UK population with COVID-19 antibodies – a measure known as seroprevalence – increased from 6.6% at the beginning of the study period in May / June 2020 to 8.8% by November / December 2020.
SARS-CoV-2 seroprevalence was most common in London, at 12.4%, and least common in Scotland, at 5.5%.
Reporting by Kate Kelland; Montage by Alison Williams