Two years into the pandemic, and political leaders are finally taking strides towards understanding the complexities of long COVID. The Biden administration released two reports last week on August 3 that address the government’s plan to advance research towards the prevention, diagnosis, and treatment services of long COVID. But for the estimated 7.7 to 23 million people currently living with longer-term symptoms and health complications from COVID, the time it takes to recover fully is still unclear.
“The short answer is it’s a bit up in the air,” says Scott Roberts, an infectious disease specialist at Yale Medicine.
In 2020, the Centers for Disease Control and Prevention (CDC) initially reported that nearly 35 percent of people infected with COVID-19 take 2-3 weeks for symptoms to go away after testing positive. But new data now estimates that 13.3 percent—nearly one in ten people—who recuperate from illness will take a month to resolve their symptoms. For people with more severe infections, such as those needing hospitalization, the CDC says that 2.5 percent are predicted to have lingering side-effects, including but not limited to difficulty breathing, muscle pain, and trouble concentrating, for three months or more.
Some scientists argue that certain individual cases will take longer to become healthy again. Over three-fourths of hospitalized COVID-19 patients in Wuhan, China showed prolonged symptoms of fatigue, muscle weakness, and sleep problems six months after discharge. A 2022 study found that one in four people took a year to fully recover from long COVID. A number of grim scenarios suggest that some people may live with long COVID for the rest of their lives. A July 2022 review of past studies of people with long COVID symptoms suggests nearly six percent of people will never recover their sense of smell and taste.
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One reason why recovery times are so difficult to estimate is because COVID-19 infections affect multiple organs in the body. “When a virus damages the body in multiple ways, you’re going to have different timelines for recovery,” says Shruti Gohil, an assistant professor of infectious diseases and associate medical director at the University of California, Irvine. For example, she says an injured nerve is going to take more time to repair than an upper respiratory tract that’s causing congestion.
Another issue is that we still don’t know what’s causing long COVID in the first place. Infectious disease experts, however, have identified some possible leads: Gohil says long COVID symptoms may be the result of the body’s overactive immune response when fighting the virus. Widespread inflammation from such a response may cause collateral damage to nearby organs and tissues.
Another prominent theory is that small, undetectable numbers of the virus are able to survive, says Sritha Rajupet, the primary care lead for the Post-COVID Clinic at Stony Brook Medicine. Rajupet explains that these persistently low viral particles might hide within nerves and tissues, causing the body to maintain a chronic inflammatory response. Another explanation is that the body could be exhibiting an abnormal immune response where it still thinks it’s fighting the initial infection. Roberts says one less popular but plausible cause is that an infection creates a hypercoagulable state, a condition that leads to increased micro blood clots from blood vessel damage, which could explain shortness of breath in people with long COVID.
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The data is also unclear on who is more likely to endure long COVID for weeks versus months. Rajupet explains that recovery rates could depend on a person’s symptoms, age, and overall health. For instance, she says individuals with severe COVID-19 symptoms or multiorgan problems during infection are susceptible to developing other conditions involving the heart, brain, or even diabetes. People who are older or immunocompromised may also have a hard time recovering from any damage to the body, which could lead to persistent symptoms after infection.
One thing all experts are sure about: vaccination helps. Research suggests vaccinated individuals with breakthrough infections were nearly half as likely than infected unvaccinated individuals to report long COVID symptoms at least four weeks after infection. However, the role of vaccines in long COVID is still up for debate. There’s other preliminary research to suggest that vaccines only help long COVID symptoms somewhat or not at all. A May 2022 study in Nature Medicine reported the vaccines only reduced the longer-term risk by 15 percent.
Infectious disease experts are still trying to unpack if vaccination, even during long COVID, can help with symptoms, says Roberts. “There’s just a lot of unknowns,” he says. “It’s an ongoing science that I imagine over time, we’ll get more data about what is going on and hopefully how to prevent and treat it.”