A new COVID variant called XEC has been spreading around the globe as respiratory virus season begins -- and many public health experts are concerned about a pattern of troublingly low COVID and flu vaccination rates in recent years.
The XEC strain, a highly contagious omicron subvariant, was first detected in Germany in June and has since proliferated across Europe.
While the XEC variant appears to be highly contagious, public health officials say its symptoms and severity seem to be similar to other COVID subvariants that are in circulation.
"It has been growing quite rapidly (in Europe)," said Dr. Scott Roberts, assistant professor in infectious diseases at the Yale School of Medicine. "But behaviorally, there's no indication it's causing changes in symptoms in any way. It looks more transmissible, but a lot of that is due to the fact that it's slightly more distinct than the current variants."
Erin Newcomer, a genomic epidemiologist at Rush University System for Health, said that XEC is considered a recombinant strain, which means "it's a mix of two strains that were already out and about."
"While the strain is new, none of the features of the strain are new," she said.
Newcomer added that the XEC strain has "just started to pop up" in the Chicago area recently and in low levels, making up 3% to 5% of the virus circulating locally.
The strain is estimated to account for about 11% of the virus circulating nationwide, with rates a little higher on the West Coast, according to the most recent Centers for Disease Control and Prevention update.
Health experts are urging the public to get the updated 2024-25 COVID vaccine as well as the seasonal flu shot, as respiratory virus season begins this month.
Approved in late August, the new COVID shot targets an omicron subvariant of the virus that was dominant at the time of its formulation and is similar to currently circulating strains, according to the CDC.
"As of a few days ago, we now have some preliminary data showing the vaccine in this fall's strain does produce antibodies that will target XEC," Roberts said. "It's not a perfect match, because it's more mutated than what the vaccine was targeted to ... but it still elicits some degree of neutralizing antibodies against XEC. So that's good news."
Nationwide, about 6% of American adults have reported receiving the 2024-25 updated COVID vaccine as of the end of September, according to the CDC.
Dr. LaMar Hasbrouck, chief operating officer of the Cook County Department of Public Health, estimated that less than 1% of eligible residents in suburban Cook County have taken the most recent updated COVID-19 vaccine. The county health department noted that it's just the start of the season and the updated shot has only been available for a few weeks; uptake for the previous shot was about 14%.
Hasbrouck urged everyone eligible to get the updated COVID shot and a seasonal flu vaccine as soon as possible, noting that both can be taken at the same time.
"There's been a vaccine fatigue," he said. "Folks just aren't taking it as seriously because we aren't seeing the deaths as much. ... I think Americans just aren't into the vaccines because the worst is over and so many people are living with COVID and the flu, and they feel inconvenienced. It's just not that high a priority for folks."
The Chicago Department of Public Health and the Cook County Department of Public Health recently announced a series of COVID and flu vaccination clinics at various locations across the area.
The city health department has also targeted five communities most impacted by the flu and COVID in the previous respiratory virus season -- West Garfield Park, West Englewood, Burnside, Hermosa and McKinley Park -- to try to increase vaccine uptake in those areas, said Dr. Olusimbo 'Simbo' Ige, Chicago's health commissioner, during a Friday news conference.
"We are going to be doing hyperlocal, targeted outreach efforts to improve flu and COVID vaccination uptake for the 2024-2025 season," she said.
COVID rates and hospitalizations have recently been declining locally following a spike in cases during the late summer and early fall across much of the U.S., according to CDC data.
Uptake of the previous COVID vaccine was generally low in Illinois and around the country, though rates tended to be higher for older populations.
Nationwide, less than a quarter of American adults received the 2023-2024 COVID shot, according to the CDC.
About 17% of Chicago residents of all ages were up to date on the previous COVID vaccination, according to the city health department's vaccine dashboard, which includes data reported through Aug. 31.
Rates were lower for city residents of color, with roughly 11% of Latino and Black residents up to date on their COVID shots in 2023-24; uptake was also low for children, teens and young adults. Older residents were more likely to get vaccinated against COVID, with 40% of those over 75 and about 35% of those 65 to 74 getting the updated shot, the data showed.
Across Illinois, a little over 14% of residents of all ages received the 2023-24 shot, according to Illinois Department of Public Health data. Rates were lower for children compared to adults, with those 65 and older being the most likely to get vaccinated statewide.
The CDC also advises everyone 6 months and older to get an annual flu shot, with rare exceptions; the agency recommends that people get vaccinated against the flu in September or October.
"Ideally, everyone should be vaccinated by the end of October," the CDC states.
Across the country, about 12% of adults reported receiving a 2024-25 flu shot as of late September, according to the CDC.
But flu shot uptake has also declined in recent years.
About 45% of American adults were vaccinated against the flu in 2023-24, a decrease from almost 47% the previous year, according to the CDC. Roughly 55% of children got a flu vaccine during the 2023-24 season, down from 57% the previous season.
Physicians and health experts have been particularly concerned about declining influenza vaccination rates of children following a rash of pediatric flu deaths during the previous respiratory virus season.
Two hundred American children died of the flu in 2023-24, exceeding the previous record of 199 pediatric deaths during the 2019-20 respiratory virus season, the CDC has reported.
The deaths in 2023-24 included 158 children who were eligible for the flu vaccine and their vaccination status was known; of those kids, 131 were not fully vaccinated, according to the CDC.
"Flu vaccination can be lifesaving for children and has been shown in several studies to reduce the severity of illness in people," the CDC said in a September report. "September and October are good times to be vaccinated."
Immunizations that protect against respiratory syncytial virus or RSV are also available for seniors and some pregnant people; infants and some children can also get an RSV antibody.
Adults 75 or older are eligible for the RSV vaccine and those 60 to 74 with increased risk of RSV should also get the shot; those who took the vaccine last year don't need to get another RSV shot this year, according to the CDC.