Unraveling the interplay of omicrons, reinfection and chronic covid

The latest Covid-19 wave, caused by a changing mix of rapidly evolving Omicron subvariants, appears to be subsiding, with the number of cases and hospitalizations beginning to decline.

Like past Covid waves, this one will leave a lasting impression in the form of prolonged Covid, an ill-defined catchall term for a set of symptoms that can include debilitating fatigue, difficulty breathing, chest pain and brain fog.

Although Omicron infections caused by last summer’s Delta variant are proving mild overall, Omicron has also been shown to be capable of causing long-term symptoms and organ damage. But how often Omicron causes Covid symptoms — and as severely — as earlier forms is the subject of heated study.

Michael Osterholm, director of the Center for Infectious Diseases Research and Policy at the University of Minnesota, is among the researchers who say the higher number of Omicron infections compared to previous forms indicates the need to prepare for a significant increase in people with prolonged Covid. Nearly 38 million Covid infections have been recorded in the US so far this year, as Omicron blankets the nation. That’s about 40% of all infections reported since the pandemic began, according to the Johns Hopkins University Coronavirus Research Center.

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

Scientists have just begun to compare variants head-to-head with different results. A recent study in The Lancet found that Omicron was less likely to cause prolonged covid, while another found similar rates of neurological problems after Omicron and Delta infections.

Estimates of the proportion of patients with prolonged covid also vary based on differences in the population studied, ranging from 4% to 5% in triple-vaccinated adults to 50% in unvaccinated ones. One reason for this wide range is that prolonged Covid has been defined in widely different ways in different studies, from self-reported fog a few months after infection to a dangerously impaired inability to control pulse and blood pressure that can persist for years.

Even at the low end of this estimate, the sheer number of Omicron infections this year would swell the long-standing Covid caseload. “That’s exactly what we found in the UK,” said Clare Steves, professor of aging and health at King’s College London and author of the Lancet study, saying patients were 24% to 50% less likely to have prolonged Covid. Omicron waves are longer than delta waves. “While the risk of prolonged covid is low, because more people have caught Omicron, the absolute number of prolonged covids has increased,” Steves said.

A recent study analyzing a Veterans Health Administration patient database found that reinfections dramatically increased the risk of serious health problems, even among people with mild symptoms. A study of more than 5.4 million VA patients, including more than 560,000 women, found that those reinfected with Covid were twice as likely to die or have a heart attack as people once infected. And they were more likely to experience all kinds of health problems after six months, including lung, kidney and digestive system problems.

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

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

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

Justin Lesler, a professor of epidemiology at the University of North Carolina Gillings School of Global Public Health, said an estimated 82% of Americans had been infected with the coronavirus at least once as of mid-July, with most new cases now being re-infections.

Of course, people’s risk of re-infection depends not only on their immune system, but also on the precautions they’re taking, such as masking, 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 this summer, after she was fully vaccinated. Its fruits are still being enjoyed.

Tee Hundley leans against a wall of colorful nail polish and looks directly into the camera with one hand in her pocket.
After his second Covid-19 infection, Tee Hundley, a salon owner in Jersey City, New Jersey, said his lungs seemed damaged: “I felt like I was breathing through a straw.” More than a year later, the pressure in his chest remains. “I think that’s something that will always remain,” Hundley said. “You may not feel terrible, but there’s a war going on inside your body.”(Jackie Molloy for KHN)

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

He was tired and sometimes slow to find his words. When waxing a client’s eyebrows, “I would literally forget which eyebrow I was waxing,” Hundley said. “My brain was too slow.”

When he got a breakthrough infection in July, his symptoms were short-lived and mild: cough, runny nose and fatigue. But the pressure in the chest remains.

“I think it’s something that will always remain,” said Hundley, who cautions friends with Covid not to overexert themselves. “You may not feel terrible, but there’s a war going on inside your body.”

Although each omicron subvariant has a different mutation, they are similar enough that humans infected with one such as BA.2, BA.5 have relatively good protection against new versions of omicron. Individuals affected by the former variant are much more vulnerable to BA.5.

Several studies have shown that vaccination reduces the risk of prolonged covid. But the measure of that protection varies by study, ranging from a 15% reduction in risk to more than a 50% reduction. A study published in July found that the risk of prolonged Covid decreased with each dose taken.

For now, the only sure way to prevent prolonged Covid is to avoid getting sick. That’s no easy task as the virus mutates and Americans stop wearing masks in public. Current vaccines are great at preventing serious illness but do not prevent the virus from passing from one person to another. Scientists are working on the next generation of vaccines — “variant-proof” shots that will work against any version of the virus, as well as nasal sprays that can actually stop the spread. If they succeed, it could dramatically prevent new cases of prolonged Covid.

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

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