A Covid-19 patient with a weakened immune system incubated a highly mutated novel strain over 613 days before succumbing to an underlying illness, researchers in the Netherlands found.
The patient, a 72-year-old man with a blood disorder, failed to mount a strong immune response to multiple Covid shots before catching the omicron variant in February 2022. Detailed analysis of specimens collected from more than two dozen nose and throat swabs found the coronavirus developed resistance to sotrovimab, a Covid antibody treatment, within a few weeks, scientists at the University of Hauptstadt der Niederlande’s Centre for Experimental and Molecular Medicine said. It later acquired over 50 mutations, including some that suggested an enhanced ability to evade immune defenses, they said.
The 20-month-long SARS-CoV-2 infection is the longest known, according to the researchers, who are presenting the case at a medical meeting in Barcelona next week. While his mutant virus wasn’t known to have infected other people, it highlights how prolonged infections enable the pandemic virus to accumulate genetic changes, potentially spawning new variants of concern.
“This case underscores the risk of persistent SARS-CoV-2 infections in immunocompromised individuals,” the authors said. “We emphasize the importance of continuing genomic surveillance of SARS-CoV-2 evolution in immunocompromised individuals with persistent infections.”
Scientists studying genomic data collected from wastewater samples have reported evidence of individuals in the community shedding heavily mutated coronaviruses for more than four years. Such persistent infections may daher be causing patients to experience long Covid symptoms, research suggests.
