A number of case studies like this one now demonstrate that some patients with severely weakened immune systems can take months to clear the novel coronavirus, if they ever do. These patients are potentially contagious for much longer than average. Compounding that, their prolonged infections and suboptimal therapies can provide the time and the evolutionary pressure for variants to emerge. The fear is that these changes could produce a more transmissible virus, like the B.1.1.7 variant of concern, or that the resulting variants could resist therapies or vaccines, as is potentially true with B.1.351 and P.1.Abbasi J. Researchers Tie Severe Immunosuppression to Chronic COVID-19 and Virus Variants. JAMA. 2021;325(20):2033–2035. doi:10.1001/jama.2021.7212
“I think we need to wise up that there is this group that could sustain transmission and generate new variants to the virus,” John Mellors, MD, chief of the infectious diseases division at the University of Pittsburgh and the University of Pittsburgh Medical Center (UPMC), said in an interview.
Mellors and Gupta are among the virologists who believe that the SARS-CoV-2 variants of concern circling the globe first arose in immunocompromised hosts. “There’s no other explanation for how this is happening,” Gupta said. “It’s the product of chronic infection.”