Reinfection with SARS-CoV-2, the disease-causing virus, is on the rise, dashing hopes that vaccination or previous illness will confer long-lasting immunity to infection. As more people become reinfected, they may wonder: Will repeated infections lead to more severe COVID symptoms?
Evidence is still limited, but available data suggests that most re-infected people recover within days, but “others are having a tougher time,” says Bethesda, Md. says Josh Fessel, a pulmonologist at the National Center for Advanced Translational Sciences in New York. Fessel and other experts say assessing the impact of reinfection, especially when new virus variants emerge and become increasingly infectious, is an urgent priority. says.
The first study on the health risks of recurrent infections was published last November. A team of researchers led by his Ziyad Al-Aly, a clinical epidemiologist at the University of Washington in St. Louis, and his colleagues found that people who were reinfected were twice as likely to die from COVID than those who were only infected. concluded that he was three times more likely to be hospitalized. 1 time, regardless of vaccination status. Al-Aly’s team reviewed data from nearly half a million of his COVID patients treated by the U.S. Department of Veterans Affairs (VA) between March 2020 and his April 2022. Of those, about 10% had SARS-CoV-2 between him and him when he was 2 years old and when he was 4 years old. times. Al-Aly said some patients remained symptomatic during his six months of follow-up, and the severity of the patient’s illness typically worsened with each new his COVID episode.
Given these findings, Al-Aly emphasizes that recurrence of infection “would result in both the acute and long-term phases of COVID.” But his results also have an important caveat: most of the VA patients were older men, averaging 63 years old, and many had pre-existing health problems, including heart disease.
“The results of this study were unexpected,” says Stanley Perlman, a microbiologist at the Roy J. and Lucille A. Carver College of Medicine at the University of Iowa in Iowa City. He was not involved in this research. “We expected relapses to be mild because of the immunity from the initial infection. According to Perlman, most hospitalizations and deaths from COVID are in the elderly and unvaccinated. , or in people with weakened immune systems.But for people outside of these groups, “I think most subsequent infections are milder than the first,” he speculates. However, they warn that it may have unanticipated immunological effects that scientists do not understand.
But recent data bolsters Al-Aly’s evidence that repeated infections can be severe, while providing new insights into what raises risk for vulnerable people. A preprint study (not yet peer-reviewed), posted in The Investigator of this Case, reported that the severity of the first bout with COVID predicted the severity if the disease struck again. reviewed electronic health records from a more diverse population of 1.5 million COVID patients treated in US hospitals between March 1, 2020 and July 1, 2022. Nearly 6% of these individuals were infected multiple times, and most reinfections occurred during the period when the original Omicron variant of him was spreading (November 2021 to mid-March 2022). .
Of patients who were first hospitalized with severe COVID, nearly half were re-infected and hospitalized again. Conversely, about 90% of people who initially had a mild infection avoided hospitalization when she later became sick again with her COVID. Notably, researchers found that reinfection was also associated with increased risk of COVID over time. These are lingering symptoms such as fatigue, shortness of breath, and brain fog months or years after the initial infection. However, the basis for this tendency is unknown. Biological factors may also be at play, and “doctors are simply keeping track of the long COVID backlog with new diagnostic codes that will become available in late 2021.” , said Emily Hadley, data scientist at RTI International, a non-profit research organization. Durham, NC, and first author of the study.
Richard Moffitt, a bioinformatics expert at the Winship Cancer Institute at Emory University in Atlanta and one at Hadley University, adds: “And it’s even harder for him to articulate two different coronavirus diagnoses from one ongoing experience.”
Ralph Baric, a virologist at the University of North Carolina (UNC) in Chapel Hill, says it makes physiological sense that the severity of the initial infection predicts the severity of future COVID episodes. “Repeated heart infections can lead to myocarditis (inflammation of the heart),” he said. [produce] It’s a blood clot,” he says. “When blood clots accumulate in various organs, they cause hypoxia. [low oxygen in tissues] This can be a problem, especially for older patients. Plus, his genetic risk for severe COVID and certain types of chronic lung disease — such as pulmonary fibrosis, a disease that scars the lungs — overlaps with each other, he says. I have a long term problem. “
Richard Boucher, a pulmonologist at the UNC School of Medicine, agrees that people with extensive scarring in their lungs are at particularly high risk of reinfection. “You worry about it when you have a patient who has COVID and is left with severe lung disease for months,” he says. “These patients are already behind the eight ball. I don’t want the virus to kick them again and worsen the fibrosis they already have.”
But new data also point to promising developments. SARS-CoV-2 is especially dangerous when it colonizes the lungs and causes systemic problems such as fever, cough and shortness of breath. Early COVID subspecies often invaded the lungs, but a recent preprint by Japanese scientists found reinfection by Omicron subspecies in people who had been vaccinated against COVID or had previously been ill. Infections tend to primarily affect the nose and upper respiratory tract. Antiviral immune attacks cause unpleasant symptoms, but also tend to heal quickly. Citing these data, these findings suggest that even if vaccination does not prevent reinfection or upper respiratory tract illness, it is likely that “worse conditions such as more troublesome systemic infections and the need for ventilators”. It helps to make sure that it can help protect you from consequences…or death.In addition, vaccines blunt the severity of initial COVID infections, which in turn limits the severity of future infections. Moffitt says it should.
“Reinfection is happening,” says Moffitt. “Most people have only been infected once, but a few have been reinfected multiple times, and that number is expected to rise.”
Editor’s Note (2/15/23): This article has been updated to correct a misspelling in Ziyad Al-Aly’s name. I’m sorry.
