July 7, 2022 — People re-infected with the virus that causes COVID-19 face increased health risks with each round of re-infection, a large national database study shows.
The researchers found that the health effects were worse during active infection, but some symptoms persisted for up to 6 months, suggesting a direct link between reinfection and infection. Corona Virus.
“Reinfection increases or contributes to additional health risks. It is not entirely benign, and people should try to avoid reinfection,” said lead study author Ziyad Al-Aly, MD.
Risks remain whether or not people are fully vaccinated.In some cases, people may have been infected earlier with the Delta strain and are now exposed to Omicron or its subvariant BA.5, which may be better at evading vaccine protection, he said.
Al-Aly, a clinical epidemiologist and director of research and research at the University of Washington, added: “The first infection may also weaken certain organ systems, making people more vulnerable to health risks with a second or third infection. Influence.” The Development of the Health Care System in St. Louis, Virginia. “There are a lot of variables at play, but it’s clear that reinfection carries additional risks and should be avoided.”
Al-Aly and his colleagues compared 257,427 people who were first infected with the virus that causes COVID-19 to a group of 38,926 who were infected a second time or later, and then to 5.4 million who had never been infected. Compare. Information for the study was obtained from veterans in the Department of Veterans Affairs Healthcare Database.
Results published online June 17 prepress research, which means it has not been peer-reviewed, a critical step in helping to evaluate and validate clinical studies.The study is undergoing journal review natural combination.
Three COVID-19 experts who were not involved in the study raised some caveats, including that the study of veterans may or may not apply to the general population.
“This is the first study to describe the risk of reinfection,” said Eric Topol, MD.
He noted that a second infection was associated with doubling the number of deaths from any cause and a doubling risk of heart or lung problems compared to the first.
The additional risk of each infection is also growing, said Topol, executive vice president of Scripps Research and editor-in-chief of Medscape, WebMD’s sister site for healthcare professionals.
“Obviously, these findings are concerning because reinfection was very rare before the Omicron wave, and throughout the delta variant ocean waves. But now reinfection is more common,” he said.
higher risk, especially for some people
When asked to comment, Dr Ali Mokdad said the study was “well done”. Al-Aly and colleagues “have access to good data, and they’ve done multiple studies.”
The elderly, immunocompromised and people with other medical conditions are more likely to face additional risks, he said.
“It makes sense, let me explain why,” Mokdad said. “When someone first gets COVID-19 and is affected by it, it’s probably someone who is older or has a chronic medical condition. A single blow will do more damage as well.”
“That’s why you would think that some people are more likely to have a more severe secondary infection,” said Mokdad, associate professor of epidemiology and professor of health metrics sciences at the University of Washington in Seattle.
“The best thing for you and the public — healthy or not, chronic disease or not — is to not get infected,” he said. “Go get your vaccines and your boosters when you’re in a crowded And wear a mask when you can’t maintain a safe distance.”
Are Veterans Risk Factors Different?
“When you look at the study, the biggest caveat is that veterans are different from the general population,” said Amesh Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health in Baltimore.
“I don’t think you can generalize [the study] For everyone, but for those with risk factors for serious illness,” he said, because veterans tend to be older and in poorer health.
He said many people who were re-infected had tested positive at home. As a result, their cases were not included in the study. By contrast, the veterans in the study were “people who wanted to be formally tested for some reason.”
Vaccines can still prevent serious illness, hospitalization and death because the virus has mutated from the vaccine, but they are less effective at preventing infection, Adalja said. “The same goes for previous immunity. For example, if you’re infected with BA.1 or Delta, your defenses against the new variants, BA.4 and BA.5, may not be very high.”
The study shows why “it’s important to keep abreast of your vaccines,” he said, “and why we need better vaccines against currently circulating variants.”
Despite these caveats, the researchers used “robust databases” and large study populations, which “gives us all confidence in the strength of this finding,” Adalja said.
Focus on long-term effects
Whether reinfection increases the risk of long-term COVID is unclear, so researchers Al-Aly and colleagues followed veterans for more than six months. They compared people who had one, two, three or more infections with an uninfected group.
Of those who were reinfected, about 13% had two infections, 0.76% had three infections, and 0.08% or 246 had four or more infections.
People who were re-infected more than doubled their risk of dying from any cause compared to veterans who contracted the coronavirus for the first time.
Although “the mechanisms responsible for the increased risk of death and adverse health outcomes from reinfection are not fully understood,” the authors say, “the findings underscore the consequences of reinfection and underscore the importance of preventing reinfection with SARS-CoV-2,” The virus that causes COVID-19.
When asked about the next steps for their research, Al-Aly said: “BA.5 appears to be a major looming challenge, and we are working to better understand it.”