Persisting coronavirus could drag out COVID-19 symptoms - National Geographic

May 20, 2022

A comprehensive study found that viral remnants can survive for months after infection in certain people, perhaps causing some symptoms of long COVID.

Most COVID-19 patients recover from their acute infection within two weeks, but bits of the virus don’t always disappear from patients’ bodies immediately.

Now a new study, one of the largest focusing on hospitalized COVID-19 patients, shows that some patients harbor these viral remnants for weeks to months after their primary COVID-19 symptoms resolve.

The study suggests that when the genetic material of the virus, called RNA, lingers in the body longer than 14 days, patients may face worse disease outcomes, experience delirium, stay longer in the hospital, and have a higher risk of dying from COVID-19 compared with those who cleared the virus rapidly.

The persistence of the virus may also play a role in long COVID, the debilitating suite of symptoms that can last for months.

Batra’s study shows that patients who had prolonged shedding during an acute infection risk more severe outcomes from COVID-19, says Timothy Henrich, a virologist and immunologist at the University of California, San Francisco who was not involved in the new research.

Batra and his team began studying persistent coronavirus infections after observing that some patients who were returning to the hospital were still testing positive for the virus four or five weeks after they were diagnosed with the initial infection.

Studies have identified the virus, or genetic material from it, in the intestines of patients four months after initial infection, and inside the lung of a deceased donor more than a hundred days after recovery from COVID-19.

Still, associating any lingering virus with long COVID will require extensive studies.

Both Geng and Henrich’s groups have reported preliminary case studies that show an improvement in long COVID symptoms after patients were treated with Pfizer's COVID-19 oral antiviral Paxlovid.

One new study compared 1.5 million unvaccinated COVID-19 patients to 25,225 vaccinated patients with breakthrough infections, and it found that vaccines significantly reduced the risk of developing long COVID symptoms 28 days after an infection.