Long COVID After Mild Infection? It Fades Within a Year

THURSDAY, Jan. 12, 2023 (HealthDay News) -- A large, new study offers reassuring news for folks dealing with long COVID symptoms such as trouble breathing, mental fog and loss of taste or smell: Most of these issues resolve within a year for those who had a mild COVID infection.

“The study provides the longest followup we have of long COVID-19 patients and offers some optimism that many of these symptoms – with support – will improve over about a year," said Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center in Nashville, Tenn., and medical director of the National Foundation for Infectious Diseases. He has no ties to the new research.

People with long COVID experience new, lingering or worsening symptoms for more than four weeks after the initial COVID-19 infection, according to the U.S. Centers for Disease Control and Prevention.

Symptoms run the gamut from fatigue, shortness of breath and cough to brain fog, dizziness and changes in taste or smell. As many as 1 in 5 adults in the United States may have long COVID.

For the study, a team at K.I. Research Institute in Kfar Malal, Israel, analyzed electronic health records of close to 2 million people in Israel tested for COVID through October 2021. They looked at COVID symptoms that lasted for more than one month, comparing conditions in vaccinated and unvaccinated people, with and without COVID-19.

What did they find? People with COVID were more likely to report loss of smell and taste, breathing issues, heart palpitations, dizziness and brain fog, but most of these symptoms improved within 12 months for those who had mild infections, the study found.

Vaccinated people who became infected had a lower risk for breathing difficulties and a similar risk for other conditions when compared with people who were unvaccinated when they got sick, the study showed.

“A year is a long time, it’s not overnight,” Schaffner said. “The need to be vaccinated continues to be very important because that prevents severe disease.”

Researchers aren’t sure why some people develop long COVID and others don't. Schaffner said there simply isn't good data that parses out which variant caused infection, whether and how much vaccination has occurred and how much time has elapsed since vaccination.

The good news is that with supportive care, including lifestyle changes, people can start to feel better, and long COVID symptoms don’t seem to last forever, Schaffner said.

Dr. Len Horovitz, a pulmonologist at Lenox Hill Hospital in New York City, also reviewed the findings.

“Mild infection, especially in vaccinated patients, was associated with resolution of symptoms after one year, even symptoms that seemed to last months after infection,” he said.

Not everyone is ready to celebrate the new findings, however.

David Putrino, director of rehabilitation innovation for the Mount Sinai Health System in New York City, has been treating people with long COVID throughout the pandemic.

“Put the cork back in the champagne,” he said after reviewing the study.

Researchers still don’t know enough about long COVID to draw any blanket conclusions about how long these symptoms will last, Putrino said. The study defined long COVID as symptoms that linger for four weeks after COVID infection.

This isn’t necessarily long COVID, he said.

“At four weeks, it may just be a long-tail recovery, so they will recover without intervention,” Putrino said. Some viruses linger a while before you feel like yourself.

The World Health Organization (WHO) defines long COVID as symptoms that persist or worsen for three months after initial COVID infection. This definition will catch more folks with true long COVID, Putrino said.

Some people with long COVID don’t return to their health care provider for follow-up, but this doesn't mean they have recovered, he also pointed out.

“For diseases like long COVID that are still routinely being miscategorized, misdiagnosed, and where patients are not carefully followed up, these large electronic health studies are harmful,” Putrino said.

The findings were published Jan. 11 in the BMJ. Barak Mizrahi, a senior researcher at the Israeli Institute for Applied Research in Computational Health, led the study.

More information

The World Health Organization provides more information on long-COVID.

SOURCES: William Schaffner, MD, infectious disease specialist, Vanderbilt University Medical Center, Nashville, Tenn., medical director, National Foundation for Infectious Diseases; Len Horovitz, MD, pulmonologist, Lenox Hill Hospital, New York City; David Putrino, PhD, director, rehabilitation innovation, Mt. Sinai Health System, New York City; BMJ, Jan. 11, 2023