The specter of COVID has tormented the world for four years—The disease has killed at least seven million people worldwide. However, the long-term effects of the pandemic are still unclear, because when it comes to a new virus like SARS-CoV-2, which causes COVID, Scientists still have a lot to learn..
What we do know is that COVID is here to stay—And that contracting it does not give people permanent immunity. Four years into the pandemic, researchers and doctors know that people are racking up multiple infections, but the long-term consequences of contract the virus repeatedly are still not clear. Fortunately, both individuals and Governments have strategies. to avoid some infections, if they use them.
“No matter how you look at it, whatever long-term health effect you look at, the risk (of reinfection) is not zero,” says Ziyad Al-Aly, a clinical epidemiologist at Washington University in St. Louis. . “The truth is, yes, we are sick and tired of the virus, we are sick and tired of the pandemic—but it’s still here. He is still harming people.”
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In the United States alone, more than 1.1 million people have died from COVID since the pandemic began, according to the Centers for Disease Control and Prevention. The agency no longer tracks infections at the community level, but in mid-January it reported that nearly four percent of deaths nationwide were caused by COVID.
And although the winter wave of infections appears to be subsiding, the world lost the opportunity to make COVID disappear. “This ugly guest will not leave us anytime soon,” says Al-Aly. “He’ll probably be here for decades.”
Early in the pandemic, scientists expected COVID to be the type of disease for which vaccination or infection creates immunity that lasts years or a lifetime. But the SARS-CoV-2 virus had other plans. Vaccination and, to a lesser extent, infection make you less vulnerable to contracting the virus and having a severe case, but that protection diminishes over time.
“An infection protects you against future infections,” but not completely, says Jamie Rylance, a doctor in the clinical management team at the World Health Organization. The SARS-CoV-2 virus mutates rapidly, so a person’s immune system cannot necessarily fully fight off a new infection, even if it has been primed by a recent attack with a different strain. The same applies to vaccines: Although initial shots and booster doses help a person’s immune system respond more effectively to an infection and reduce the chances of a severe case of COVID, Current COVID vaccines cannot prevent infection completely..
To further complicate matters, COVID often triggers asymptomatic infections, which helped the virus continue to spread early in the pandemic even in places where governments established relatively strict containment protocols. And four years into the pandemic, many people are getting tested for COVID less frequently and Testing misses many asymptomatic cases., making them even more difficult to identify. Therefore, it is likely that people have been infected more times than they realize.
“We don’t know how often we get reinfected because we have some protection from vaccination or even past infection,” says Maria Van Kerkhove, acting director of the WHO’s Epidemic and Pandemic Preparedness and Prevention department. However, she doesn’t think it’s something she should feel complacent about. “We know that when the virus enters our body, affects multiple organ systems,” she says.
The combined evidence on COVID and the long-term impacts of other viruses paints a bleak picture of what it could mean to experience regular COVID infections.
“Every time you get infected (with COVID), you damage the body in some way,” says Avindra Nath, a neurologist at the National Institutes of Health who has led research on long COVID and other post-viral conditions. For example, a lung infection can scar the lungs or cause blood clots. COVID can also interfere with the immune system itself, he says. Nath notes that the protective sheaths of many viruses include regions that can interfere with the immune system. Furthermore, a study that followed participants after a flu infection found that in about 30 percent of people, the the immune system remained somewhat impaired two months later.
And because COVID is still relatively new, scientists realistically have no idea what happens 10, 20, or even 30 years after an infection, let alone multiple episodes. “What we need to be able to track are complications of lung function (and) heart function five years from now, 10 years from now,” Van Kerkhove says.
It’s frustrating that we never have a clear idea of the damage COVID reinfections are causing, says Sunil Ahuja, an infectious disease specialist at the University of Texas Health Science Center in San Antonio. “Attributing cause and effect is a big challenge,” he says of the potential long-term consequences of repeated COVID attacks. During the time period between infections, “a lot of other things happened to them as well.”
Some viruses can hide in the body and emerge decades after the initial infection to cause new problems. The virus that causes chickenpox, for example, can trigger shingles many years later. And scientists have recently discovered that infection with the common Epstein-Barr virus seriously increases risk of a person who develops the autoimmune disorder multiple sclerosis. “I don’t think we’ve seen the end of this movie yet,” Al-Aly says of the long-term impacts of SARS-CoV-2.
Additionally, COVID has already demonstrated its potential to cause lasting damage in the form of long COVID, which can include debilitating fatigue, respiratory problems, difficulty thinking, digestive problems and a wide variety of other symptoms. As of mid-2023, long COVID affected 11 percent of Americans who reported a prior infection.a notable drop compared to the previous year. Scientists are still working to determine what triggers long COVID, but it’s clear that people can develop the condition after several infections, not just after their first encounter with COVID.
“Any time you have COVID, you have the possibility of having a post-COVID condition,” Rylance says, although he adds that “it’s still pretty unpredictable on an individual level.”
While scientists desperately want more data to better understand the ways COVID could affect a person’s health for years to come, the clues available now are worrying, experts say. “There is a big concern here that people who get repeated infections could have long-term consequences,” Nath says. “And the data “What is coming to light suggests that possibility.”
Although COVID is now endemic and circulating widely, both individuals and societies can work to minimize the chances of infection, Van Kerkhove and Al-Aly say. For individuals, get vaccinated and masking in public and crowded spaces They remain the most effective strategies to avoid COVID or reduce the severity of an infection. Unfortunately, only one in five U.S. adults had received the updated 2023-2024 COVID vaccine as of mid-January, according to the CDC, although initial analysis of the vaccines shows they are about 50 percent effective against infections. , even by the last subvariant, known as JN.1. COVID test when you feel unwell and the use of antiviral medications such as Paxlovid also remain vital tools in reducing the risk of disease.
WHO’s Van Kerkhove says government action is key, including ensuring masks, vaccines, tests and treatments are available and affordable. But he also called on governments to take bolder steps, such as Strengthen ventilation requirements in buildings. and support the development of better vaccines, including an oral or nasal vaccine that could more effectively prevent against COVID in the respiratory tract, where the virus enters a person’s body. Additionally, Al-Aly says, we need a longer-lasting vaccine that offers significant protection for several years, so that people do not need to be vaccinated every year.
“Really developing the technology and offering those solutions is not beyond the reach of American medicine,” Al-Aly says of these next-generation vaccines. He says the investment is particularly important now that we understand that COVID is not a problem we can quickly do without, and as concerns grow about the harm of repeated infections.
“Those will be the long-term sustainable solutions,” says Al-Aly. “It’s not sustainable to ask people to wear masks for the next 100 years.”