Dr Katie Doores, lead author on the study at King’s College London, said: “People are producing a reasonable antibody response to the virus, but it’s waning over a short period of time.
“Depending on how high your peak is, that determines how long the antibodies are staying around.”
The study found that antibody levels fell as much as 23-fold over the three month period period, and in some cases even became undetectable.
Another study published in The New England Journal of Medicine also suggests that antibodies developed after a mild infection and disappeared within a few months.
Analysing samples from 34 participants, they found the antibodies had a half-life of 73 days – meaning half of the antibodies would have disappeared after 73 days.
The study’s authors, led by Otto Yang, “call for caution regarding antibody-based ‘immunity passports,’ herd immunity, and perhaps vaccine durability.”
Dr Yang, of UCLA, added: “The big caveat is of course that this is just one snapshot for a relatively short period of time so we don’t know that it will continue that same rate of drop over time.”