COVID-19 antibodies ‘last at least six months’ in most people

A study of almost 1,700 people suggests that, six months after infection, up to 88% of people still have antibodies in their blood that can fight against COVID-19.

The data comes from one of the world's largest studies to follow up with COVID-19 patients and also provided more details about the symptoms that those who had the virus are likely to have experienced.

A high number (43%) reported losing their sense of taste or smell, while others reported having a cough (26%) or a fever (28%). Equally of interest was that 40% of participants experienced none of these symptoms, and about 20% had no symptoms at all.

The data also confirmed previous studies that showed that younger adults, black or South Asian people and those living in deprived areas were most likely to have had COVID-19 and therefore test positive for the antibodies.

The UK Biobank holds the genetic data of half a million people who volunteered to have their information analysed to help with global medical research and from this group, just under 20,000 gave a blood sample between May and December last year.

Of those blood samples, 1,699 tested positive for antibodies for COVID-19. Most tested positive early on in the study, suggesting that they had become infected in the first wave.

Six months later, when the study ended, 88% still had detectable antibodies. Smaller studies that had been done previously in healthcare workers had similar findings.

UK Biobank chief scientist Prof Naomi Allen said: "The results suggest that people may be protected against subsequent infection for at least six months following natural infection. More prolonged follow-up will allow us to determine how long such protection is likely to last."

While 12% of those who initially tested positive for antibodies then tested negative, it is thought that they could have retained some protection against subsequent infection even though their antibodies had fallen below the threshold measured by the study.