A British man who had COVID for 411 days is thought to have had the virus longer than anybody else in the world and survived.
The patient, who has a weakened immune system after a kidney transplant, first tested positive in December 2020.
Despite losing symptoms he continued to test positive until January 2022.
Medics at Guy's and St Thomas' Hospitals in London say they're not aware of any other documented case of a person being cured after such a long infection.
They used genetic analysis to determine that the unnamed 59-year-old still had an early variant of the original Wuhan strain - one which had long since been overtaken by Alpha, Delta and Omicron in general circulation.
Only when they had identified the variant could they cure him with Regeneron, the same drug cocktail that helped Donald Trump to fight the illness.
The same team also treated a patient with an underlying health condition who died after testing positive for 505 days.
In both cases genetic testing showed that the patients had not been reinfected.
Cases of persistent infection are different to long COVID, where a patient can display symptoms for months or longer but does not test positive.
The team treating the cases have called for more research into antibody treatments for persistent COVID cases and campaigners have called for a new medication - Evusheld - to be made available in the UK and Europe.
Dr Luke Blagdon Snell said: "Some new variants of the virus are resistant to all the antibody treatments available in the UK and Europe.
"Some people with weakened immune systems are still at risk of severe illness and becoming persistently infected. We are still working to understand the best way to protect and treat them."
The team's findings are published in the journal Clinical Infectious Diseases.