New ‘FLiRT’ Variants Spark Summer COVID Surge Warning

April 30, 2024 – In recent weeks, COVID-19 forecasters have reported on a new set of variants picked up in wastewater surveillance. Nicknamed FLiRT, they’re threatening to cause a new wave of COVID infections, which recently bottomed out after spiking in December. 

Models released last week from Jay Weiland, a data scientist who has accurately predicted COVID waves since the beginning of the pandemic, warns that a surge is on the horizon. “He’s someone who many experts like myself follow because he’s been pretty accurate so far,” said Megan L. Ranney, MD, dean of the Yale School of Public Health.

Ripe for Reinfection

What’s more, said Ranney, FLiRT also has some concerning features, like changes in the spike protein, which play a role in helping SARS-CoV-2, the virus that causes COVID-19, take hold, colonize the body, and make people sick.

Host vulnerability is another troubling factor, given that only 22% of American adults have gotten the latest COVID vaccine. And since many people may not have had the virus in a while, they’re ripe for reinfection. 

“We’ve got a population of people with waning immunity, which increases our susceptibility to a wave,” said Thomas A. Russo MD, chief of infectious disease at the Jacobs School of Medicine and Biomedical Sciences at the University of Buffalo.

There’s also some concerning data that shows that even those who have gotten the newest COVID booster may not be well-protected against a potential surge. A preprint study released this week from researchers at Harvard University shows compelling evidence that the newest booster isn’t holding up well against JN.1, the most recent dominant variant, and its FLiRT offshoots. The study has not yet been peer-reviewed. 

JN.spread globally over the winter and still makes up 95% of COVID cases in the U.S. Its lineage is the Omicron variant, which has been circulating in some form since 2021. Still, new variants can quickly take hold. JN.1 made up almost none of the cases in mid-November but quickly jumped to 21% in December and 85% by the third week of January.

In recent years, COVID waves have also fallen into a predictable rhythm, with a large winter wave and a smaller mid- to late-summer peak, largely due to people spending so much time in air-conditioned indoor settings with poor ventilation as the weather outdoors heats up, said Russo.

“All these factors considered, if I were to look in my crystal ball, I would say that we’re going to have another wave or increase in cases and hospitalizations sometime this summer,” he said.

Protecting Yourself Against a Summer Surge

Even though there is some question about how the new booster will hold up against the latest variants, staying up to date on vaccinations is still the best way to protect yourself. For those who haven’t gotten the latest booster, time is of the essence. And for those who are over age 65 or immunocompromised, the CDC recommends getting a second updated COVID booster 4 months from their last booster. 

“Assuming that the virus continues to evolve and our immunity wanes, the general population is likely to continue to need an annual booster for protection,” said Ranney. 

And many experts said we need to take the virus more seriously. In general, if you’re sick, don’t go to work, go out, or travel, and give yourself time to recover so that you don’t get everyone around you sick. The CDC recommends that people stay home and isolate until at least 24 hours after any fever is gone and overall symptoms have improved. And if you’re in a crowded area with poor ventilation, a mask is still a simple and effective tool for protection. 

New treatments like the monoclonal antibody Pemgarda, which the FDA granted emergency use authorization in March, may also help protect those who are particularly vulnerable to a spring or summer surge, said Shirin Mazumder, MD, an infectious disease doctor at Methodist Le Bonheur Healthcare in Memphis. The drug is to be taken as a preventive measure for anyone who is moderately to severely immunocompromised. The medication is given through an IVbefore a patient’s potential exposure to COVID. It’s designed for those who are unlikely to build up enough immunity and may need more protection from the virus. 

“It’s another tool that can help people in addition to getting vaccinated and taking other precautions,” said Mazumder.

The Increasing Risk of Long COVID

Vaccination is also important for protection against long COVID, according to a March 2024 study published in The Lancet Respiratory Medicine. And for Grace McComsey, MD, who leads the long COVID RECOVER study at University Hospitals Health System in Cleveland, it’s not the risk of acute illness that’s most alarming. 

She said long COVID is becoming the bigger issue for those who might not have been as fearful of acute COVID. Research released from The Lancet Infectious Diseases recently showed that many of those who end up with long COVID – a chronic illness marked by fatigue, brain fog, and heart and lung problems – didn’t necessarily have a severe bout with the infection.

Numbers of long COVID cases are also on the rise, with 6.8% of Americans reporting long COVID symptoms, up from 5.3% in 2022. In all, 17.6% said that they’ve had it at some point, according to a survey from the CDC. “Long COVID is what I’d be most concerned about right now, given that its numbers are rising and it can make you chronically ill, even if an acute infection did not,” said McComsey

We don’t know for sure what this variant will do, but we do know that COVID has thus far been excellent at spreading disease and evading immunity. Whether or not this is the next variant to take hold is hard to know for sure, but if not this one, another variant certainly will, McComsey said.

“We need to respect this virus and take it seriously, because whether we like it or not, it’s here and it’s still making people really sick,” she said.