MIAMI — South Florida doctors are seeing more people with cough, fever and other flu-like symptoms as a rapidly spreading influenza strain circulates across the country this winter.

Most states in the U.S. reported “high” or “very high” levels of influenza-like illness during the week of Christmas, with a record number of outpatient visits recorded for flu-like symptoms since at least the 1997-98 flu season, federal data shows.

So what’s behind the rise?

Lower vaccination levels. Record holiday travel. The arrival of subclade K, a strain of influenza that appears better equipped at evading existing immune protections.

“All of those things make a somewhat perfect storm so that we have more cases and more hospitalizations related to influenza this year than previously,” said Dr. Geeta Sood, an infectious disease expert and an assistant professor at Johns Hopkins University.

And it’s not just flu going around. COVID-19 and RSV are starting to tick up, too.

“This is something we deal with every year,” said Dr. Mary Jo Trepka, an infectious disease epidemiologist at Florida International University.

“There are things that people can do to protect themselves and help protect others,” she added, noting that people can get vaccinated, mask up if they want, stay home if sick and take flu medication to help with symptoms.

How much flu, COVID and RSV is there in Florida?

Florida is one of many states reporting “very high” levels of influenza-like illness, according to data from the U.S. Centers for Disease Control and Prevention. That means many people are experiencing cough, fever and sore throat — common symptoms of flu, the common cold, COVID and other respiratory illnesses.

There are “moderate” levels of flu and RSV viral activity in the state’s wastewater, with “very low” levels of COVID-19, federal data shows. Experts use wastewater data to get an idea of what viruses are circulating in a community.

Remember, some people get sicker than others. Young children, seniors and people with preexisting health conditions, for example, are at higher risk for severe illness.

Florida ERs are seeing “very high” levels of people coming in with the flu, CDC data shows. ERs have seen “high” levels of RSV, but it appears to be decreasing. COVID-19 levels remain “very low” but appear to be increasing.

Will we see more flu in Miami and the rest of South Florida?

Baptist Health South Florida, the largest health system in the region, has seen more patients seeking care for flu-like symptoms compared to previous years, according to Dr. Ernesto Sanz, a medical director of Baptist Health urgent care centers. Broward Health, one of the public hospital systems in Broward County, also saw more patients sick with flu-like symptoms the last two months of 2025 compared to the previous year.

Most patients sick with the flu have been able to go home to recover, according to Sanz. Most have tested positive for influenza A, similar to the rest of the country. And unlike previous years, he hasn’t seen a lot of people sick with COVID.

The other good news: There may be some brief relief for people in Miami-Dade County. Miami-Dade ER visits for influenza-like symptoms have recently begun to tick down. Baptist Health has also recently noticed a slight decrease in flu-related urgent care visits, according to Sanz.

However, it’s too soon to know whether that decreasing trend will continue, according to doctors and public health experts. It’s not uncommon for viruses to spread more easily after the holidays, when people go back to school and work after traveling and gathering for parties.

Plus, it is still flu and cold season after all, which means we can expect to see people coughing and sniffling for a while longer. Flu season typically runs to May.

U.S. flu, COVID and RSV update

•The CDC is describing this 2025-2026 flu season as “moderately severe,” with more than 11 million reported cases of influenza, 120,000 flu-related hospitalizations and 5,000 flu-related deaths so far. Of those deaths, nine were children.

•A mutated form of the influenza A strain H3N2 known as clade K or subclade K is behind many of the reported flu cases in the U.S. this season. Subclade K caused a severe flu season in several other countries, too.

•“Seasonal influenza activity is elevated and continues to increase across the country,” the CDC said in its Monday update. “RSV activity is elevated in many areas of the country with emergency department visits and hospitalizations increasing among children 0-4 years old. COVID-19 activity is low but increasing nationally.”

Does the flu vaccine work against subclade K? Is there still time to get it?

Influenza, like other viruses, constantly mutates. And the “K” variant that has gained ground in the country was identified months after scientists had selected the strains to include in this year’s flu vaccine formulation.

Even so, the existing flu vaccine is expected to provide some protection against the new subclade K variant that is going around, according to Sood and Trepka.

And no, it’s not too late to get the influenza vaccine, according to the public health experts.

The CDC has traditionally recommended flu vaccines for people six months and older to help reduce risk for severe illness, though that changed this week. Health officials on Monday announced they would be scaling back the number of recommended vaccines for kids from 17 total to just 11. The CDC, which is overseen by U.S. Secretary of Health and Human Services and vaccine skeptic Robert F. Kennedy Jr., now says flu vaccines should only be given to a child if a doctor recommends them.

Most health insurance plans, including Medicare and Medicaid, provide free flu vaccines at in-network providers. People without insurance can often get free or low-cost flu vaccines at local health departments and community health centers.

It takes about two weeks after getting the flu shot for the body to develop antibody protections against the virus.

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