Studies Show Varied Times to Clear COVID in Immunocompromised Patients

Two new studies have demonstrated that immunocompromised patients, including those with cancer and HIV, all have varied times until they clear a COVID-19 infection, and some are at increased risk for persistent COVID-19 infections.

The first study, published by The Lancet Microbe, involved 150 immunocompromised patients with COVID-19 in the U.S. in 2022. The researchers aimed to “measure how long the patients tested positive for COVID-19, as persistent infections had been widely reported by clinicians treating patients with compromised immune systems.” There has also historically been a fear that immunocompromised patients with persistent viruses could act as a source for new mutated variants.

The team, led by Adam Lauring, MD, PhD, found that “only 25% of patients tested positive on [PCR] tests for 21 days or longer after onset of illness, and only 8% tested positive for live virus for 21 days or longer. In all, the median time to last positive test overall was 9 days in immunocompromised patients.” Among other discoveries, the team found that patients with HIV and B-cell cancers like leukemias and lymphomas were more likely to have prolonged infections, and patients with non-B-cell malignancy and autoimmune or autoinflammatory conditions had a shorter time to viral clearance.

In addition, the team found that “in patients with prolonged infections, there was limited evidence of dangerous virus mutations.” The authors wrote that the mutations that did arise within patients have “rarely, if ever, been detected in subsequent SARS-CoV-2 sequences in global databases,” and they were “only weakly predictive of subsequent omicron mutations at a population scale.”

The second study, which was published in Science Translational Medicine, highlighted the “varied risk of persistent COVID-19 infection among immunocompromised patients, with patients who were more severely immunocompromised more likely to have prolonged infections.” The authors wrote that, in accordance with the first study, “the risk of chronic SARS-CoV-2 infection is not uniform across immunosuppressive conditions and provide clarity on which immunosuppression conditions predispose individuals to delayed SARS-CoV-2 RNA and culture clearance as well as viral evolution.”

The patients included in the study who had non-severe immune suppression “had similar viral shedding dynamics to non-immunocompromised participants,” whereas people with severe immunosuppression had median times that were much higher. First author Yijia Li, PhD, highlighted the notion that “these results provide reassurance that most patients with mild/moderate immunosuppression…will be able to clear the virus during the acute phase of infection.”

CIDRAP has the release on their website.