A patient who tested positive for Covid-19 for 411 days was finally cured by a combination of antibodies, British researchers announced on Friday November 4. The latter had to genetically analyze his virus to find the right response to the disease.
The patient, whose immune system was weakened by a kidney transplant, contracted the disease in December 2020. He continuously tested positive until January 2022.
A persistent infection, different from a long Covid or repeated episodes of the disease, can strike a small number of patients with already weakened immune systems. They can test positive for months or even years, the infection “rumbling all the time”explained Luke Blagdon Snell, infectious disease specialist at the Guy and St Thomas foundation of the British public health service (NHS).
In about half, symptoms persist, such as lung inflammation, he told AFP, adding that there were still many unknowns about Covid-19. In a study published in the journal Clinical Infectious Diseasesa team of researchers, led by Luke Blagdon Snell, describes how a 59-year-old man finally overcame his infection after more than 13 months.
To find out if he had been contaminated several times or if he had a persistent infection, the researchers used rapid genetic analysis (nanopore sequencing). The results showed that it was the second hypothesis. So the researchers administered a combination of monoclonal antibodies, casirivimab and imdevimab, which apparently worked.
But this success is linked to the fact that the patient was infected with an old version of the coronavirus. This variant, dominant in late 2020, has since been superseded by other incarnations. Gold “the new variants (…) are resistant to all antibodies available in the UK, EU, and even the US”notes Luke Blagdon Snell.