Researchers who studied the virus from nine COVID-19 patients in London, also provide evidence that
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The team, from King’s College London and Guy’s and St Thomas’ NHS Foundation Trust, were also interested in how COVID-19 infection changes over time in immunocompromised individuals.
Some of these variants transmit more easily among people, cause more severe diseases, or make the vaccines less effective. One theory is that these viral variants evolve in individuals whose immune systems are weakened from illness or medical treatments like chemotherapy, who can have persistent infection with COVID-19.
The study involved nine immunocompromised patients who tested positive for the virus for at least eight weeks. Infections persisted for 73 days, on average, but two patients had persistent infections for more than a year.
The patients, who were studied between March 2020 and December 2021, had weakened immune systems due to organ transplantation, HIV, cancer, or medical therapies for other illnesses.
Regular sampling and genetic analysis of the virus showed that five of the nine patients developed at least one mutation seen in variants of concern. Some individuals developed multiple mutations associated with variants of concern, such as the Alpha, Delta, and Omicron variants.
The COVID-19 virus from one individual contained 10 mutations that would arise separately variants of concern, such as the Alpha, Gamma, and Omicron variants.
This provides evidence that mutations found in variants of concern do arise in immunocompromised patients and so supports the idea that new variants of the viruses may develop in immunocompromised individuals.
Five of the nine patients survived. Two of those five cleared SARS-CoV-2 infection without treatment, two cleared the infection after treatment with antibody therapies and antivirals, and one individual has ongoing infection.
At their last follow-up in early 2022, the patient with ongoing infection had been infected for more than one year (412 days). At their last follow-up in early 2022, the patient with ongoing infection had been infected for more than one year (412 days).
The person has been treated with monoclonal antibodies to try to clear their infection. If this person remains positive at their next follow-up appointment, they will likely pass the previous longest known infection of 505 days described in this report.
Source: Medindia
