Unraveling the interaction of Omicron, reinfections and long COVID

The latest covid-19 surge, caused by a changing mix of rapidly evolving omicron subvariants, appears to be decreasingas cases and hospitalizations begin to decline.

Like past waves of covid, this one will leave a lasting mark in the form of long covid, a vaguely defined catch-all term for a set of symptoms that can include debilitating fatigue, shortness of breath, chest pain and brain fog.

Although omicron infections are it turns out to be easier generally compared to those caused by last summer’s delta variant, omicron also proved capable of causing long-term symptoms and organ damage. But whether omicron causes long-term Covid symptoms as often — and as severely — as previous variants is a matter of heated study.

Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, is among the researchers who say the far greater number of omicron infections than earlier variants signals the need to prepare for a major push in people with prolonged covid. The US has recorded nearly 38 million covid infections so far this year as omicron swept the nation. That’s about 40% of all infections reported since the start of the pandemic, according to Johns Hopkins University Center for Coronavirus Research.

Long Covid “is a parallel pandemic that most people don’t even think about,” said Akiko Iwasaki, a professor of immunobiology at Yale University. “I suspect there will be millions of people who will get long covid after omicron infection.”

Scientists have only just begun to compare variants directly with different outcomes. While a recent study in The Lancet suggests omicron less likely to cause long covid, another found the same frequency of neurological problems after omicron and delta infections.

Estimates of the proportion of patients affected by prolonged covid also vary, from 4% to 5% in triple-vaccinated adults to about 50% among the unvaccinated, based on differences in the study populations. One reason for this wide range is that long-term covid has been defined in many different ways in different studies, ranging from self-reported fogginess for several months after infection to a dangerously impaired inability to regulate heart rate and blood pressure that can last for years.

Even at the low end of these estimates, the sheer number of omicron infections this year would increase the number of long-term COVID cases. “This is exactly what we found in the UK,” said Clare Steeves, professor of aging and health at King’s College London and author of the Lancet study, which found that patients were 24% to 50% less likely to develop long covid during the omicron wave than during the delta wave. “Even though the risk of long covid is lower, because so many people have caught omicron, the absolute numbers with long covid have gone up,” Steves said.

A recent study analyzing a database of patients from the Veterans Health Administration found that repeated infections dramatically increase the risk of serious health problems, even in people with mild symptoms. The study of more than 5.4 million VA patients, including more than 560,000 women, found that people reinfected with covid were twice as likely to die or have a heart attack as people infected only once. And they are much more likely to experience health problems of all kinds after six months, including problems with the lungs, kidneys and digestive system.

“We’re not saying a second infection will feel worse; we’re saying it increases your risk,” said Dr. Ziyad Al-Ali, chief of research and education at the St. Louis Veterans Affairs Health Care System.

The researchers say the study, published online but not yet peer-reviewed, should be interpreted with caution. Some note that VA patients have unique characteristics and tend to be older men with high rates of chronic conditions that increase the risks of prolonged covid. They cautioned that the study results cannot be extrapolated to the general population, which is generally younger and healthier.

“We need to confirm these findings with other studies,” said Dr. Harlan Krumholz, director of Yale New Haven Hospital’s Center for Outcomes Research and Evaluation. Still, he added, the VA study has some “disturbing implications.”

With approx 82% of Americans after having been infected with the coronavirus at least once as of mid-July, most new cases are now reinfections, said Justin Lessler, a professor of epidemiology at the University of North Carolina’s Gillings School of Global Public Health.

Of course, people’s risk of re-infection depends not only on their immune systems, but also on the precautions they take, such as wearing masks, getting booster shots and avoiding crowds.

New Jersey salon owner Tee Hundley, 43, has had Covid three times, twice before vaccines were widely available and again this summer after she was fully vaccinated. She is still dealing with the consequences.

After her second infection, she returned to work as a beautician at her Jersey City salon, but struggled with illness and shortness of breath for the next eight months, often feeling like she was “breathing through a straw.”

She was exhausted and sometimes slow to find her words. While waxing a client’s eyebrows, “I would literally forget which eyebrow I was waxing,” Hundley said. “My brain was so slow.”

When she got a sudden infection in July, her symptoms were short-lived and milder: a cough, runny nose and fatigue. But the tightness in her chest remains.

“I feel like it’s something that’s always going to be there,” said Hundley, who warns friends with covid not to overexert themselves. “You might not feel terrible, but there’s a war going on inside your body.”

Although each omicron subvariant has different mutations, they are similar enough that people infected with one such as BA.2 have relatively good protection against newer omicron versions such as BA.5. People affected by earlier variants are much more vulnerable to BA.5.

Several studies have discovered this vaccination reduces the risk of long covid. But the measure of this protection varies from study to study, from at least a 15% discount at risk of more than 50% discount. A study published in July found that the risk of prolonged covid decreased with each dose people received.

For now, the only sure way to protect yourself from a long covid is not to get sick. This is no easy task as the virus mutates and Americans have largely stopped wearing masks in public. Current vaccines are great at preventing severe disease, but they do not prevent the virus from being passed from one person to another. Scientists are working on next-generation vaccines — “variant-resistant” shots that would work against any version of the virus — as well as nasal sprays that could actually prevent the spread. If they succeed, it could dramatically limit new cases of prolonged covid.

“We need vaccines that reduce transmission,” Al-Ali said. “We needed them yesterday.”

KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism on health issues. Along with policy analysis and polling, KHN is one of three major operational programs in the KFF (Kaiser Family Foundation). KFF is a charitable, non-profit organization providing information on health issues to the nation.

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