New evidence suggests catching the coronavirus a second time may increase long-term health risks, a worrying development as the circulation of increasingly contagious Omicron subvariants leads to re-infection of more Californians .
Earlier in the pandemic, it was assumed that the infection offered some degree of long-lasting protection, perhaps for a few months.
However, as the coronavirus mutates, this is no longer a given. And each individual infection not only carries a risk of acute illness, but also the potential for developing long COVID.
“The additive risk is really not insignificant, not negligible. It’s really substantial,” said Dr. Ziyad Al-Aly, clinical epidemiologist at Washington University in St. Louis and chief of research and development at Veterans Affairs Saint Louis Healthcare System.
According to a preprint study examining American veterans, of which Al-Aly was the lead author, being infected twice or more “contributes to additional risks of all-cause mortality, hospitalization and adverse health effects” in various organ systems, and can further aggravate the risk of diabetes, fatigue and mental disorders.
“Reinfection absolutely adds risk,” Al-Aly said. The study suggested that, compared to people infected just once, people who caught the coronavirus a second time had a 2½ times higher risk of developing heart or lung disease and blood clotting problems. Subsequent infections were also associated with a higher risk of potentially serious health problems, as well as death from COVID-19.
It’s possible that a repeated coronavirus infection will leave someone fine, which happens to most people, Al-Aly said. “But you could be one of the unlucky ones and…have a really serious health issue with an infection.”
Los Angeles County Public Health Director Barbara Ferrer recently cited Al-Aly’s preprint study as justification for wearing masks in indoor public places to prevent reinfection.
“They also found that people with repeat infections were at higher risk for gastrointestinal, kidney, mental health, musculoskeletal and neurological disorders, as well as diabetes,” Ferrer said of the study. study. “In addition, the risk of developing a long-term health problem increased further with each reinfection. The risk of having long-term health problems was three times higher for those infected than for those who were not infected.
Older viruses, such as those that cause measles and chickenpox, are quite stable, meaning vaccines are very effective and surviving either disease usually confers lifelong immunity.
This is not the case with the coronavirus, which has mutated enormously since the start of the pandemic. Someone who was infected with the variant that dominated California at the end of 2020, for example, was vulnerable to catching the Delta variant the following summer. And those who survived Delta ran the risk of catching the latest Omicron variant.
But the reinfection landscape was further turned upside down as California fell victim to a family of increasingly transmissible Omicron subvariants. The newest of these, BA.5, showed particular skill in re-infection – with the ability to target even those who had survived an earlier case of Omicron a few weeks earlier.
“This concept of boosting immunity really only works if you encounter the same beast over and over and over again,” Al-Aly said. But in the world of COVID-19, BA.5 is actually a “very different beast” from previous variants.
It is possible that the acute phase of a second episode of COVID-19 will be milder than the first. But a subsequent attack can still leave greater cumulative damage on the body than if there had been just one infection.
Think of coronavirus infections like earthquake sequences: an aftershock may be less severe than the first tremor, but it may accumulate more damage. And just because your home is still standing after an earthquake doesn’t mean you shouldn’t explore ways to make it more seismically safe.
“Part of the reason things, for a lot of people, don’t look so bad right now is because we’re being very aggressive in fighting the virus with vaccines. , with treatments,” Dr. Ashish Jha, White House COVID-19 response coordinator, said at a Hill-hosted health care summit. “If we take our foot off the pedal, we’re going to see this virus come back in a much more dangerous way. So we have to stay on that front and keep fighting this stuff.
When it comes to long COVID specifically — a condition in which symptoms can persist months or even years after an initial infection — getting vaccinated and boosted likely reduces risk, but studies differ on how much protection there is.
“I think having pre-existing immunity – whether natural or from a vaccine – seems to reduce your risk of long COVID, but it’s still there. It’s not zero,” said Dr. Steven Deeks, professor of medicine at UC San Francisco and principal investigator of the Long-Term Impact of Novel Coronavirus Infection Study, or LIINC.
Another report, observing triple-vaccinated Italian healthcare workers who were not hospitalized with COVID-19, found that two or three doses of vaccine were associated with a lower prevalence of long COVID.
A separate report suggested that even adults who had received a booster dose still need to consider the risk of long COVID. A UK report said that during the first wave of Omicron, around 1 in 25 triple-vaccinated adults reported having long COVID three to four months after their first infection.
Still, some clinicians say people with long-term COVID tend not to get vaccinated or miss their boosters.
“The number of patients I see who have been vaccinated and boosted and come in with long COVID is very low,” said Dr. Nisha Viswanathan, director of the UCLA Health Long COVID program.
Long COVID also does not prevent you from becoming infected with the coronavirus again. Viswanathan said she had patients who saw their long COVID symptoms improve, then got sick with another episode of COVID-19, then saw long signs of COVID return.
The best way to prevent long COVID is not to catch COVID-19. Many officials and experts cite non-pharmaceutical interventions such as masking as key tools because vaccinations reduce, but do not entirely eliminate, risk.
“Masking is not a terrible thing to ask people, especially in probably the busiest places and places that have perhaps the highest risk of transmission,” Viswanathan said. Doing activities outdoors is also safer than being exposed indoors.
Some of Viswanathan’s patients have downplayed the risk of COVID-19, commenting that it has turned into a mild disease and adding that they don’t see the point in taking precautions. But, she said, a better understanding of long COVID and its crippling effects would help people understand the importance of masking up and getting vaccinated and boosted.
A UCLA study published in the Journal of General Internal Medicine, of which Viswanathan was a co-author, found that of 1,038 patients with symptomatic COVID-19 between April 2020 and February 2021, nearly 30% developed a long COVID. The most common symptoms were fatigue and shortness of breath in hospitalized patients.
While many are weary of preventive measures against COVID-19 after nearly two and a half years, they remain important, said Dr. Anne Foster, vice president and director of clinical strategy for the University of California.
The long COVID burden following this wave is unknown. Official case counts are likely vast undercounts, given that so much home testing is being used, and that could suggest the burden of long COVID in the months ahead will be difficult to predict, Foster said.
“I know everyone’s moved on and people are going back to where they are now, and I kind of get it,” Deeks said. “But people need to be aware that there is this extra risk that doesn’t go away and they might adjust their lives accordingly.
“But everyone will find out for themselves.”