Prepare now for what could be a rough flu season

Florida public health officials say influenza cases are beginning to rise throughout much of the state, a trend that could be the start of a rough winter for respiratory illnesses.

A new strain of flu is circulating that officials say could cause widespread illness. The strain, which was unexpected and was not included in this year’s flu vaccine, is a novel type of the H3N2 influenza A virus called subclade K. The United Kingdom is reporting increased flu outbreaks so far this year from subclade K. According to the Centers for Disease Control and Prevention, the strain is already the dominant type of flu in circulation in the United States.

H2N2 flu variants are typically more aggressive.

“It is a new strain,” says Dr. Pauline Rolle, medical director of pediatrics for Northeast Florida and Southeast Georgia Primary Care at Ascension St. Vincent's. “Data out of England show there are quite a few hospitalizations from this subclade.  But in the U.S., we are still collecting real-world data to figure what the impact is going to be.”

Flu is a miserable condition that causes fever, chills, cough, sore throat, runny nose, body aches, headache, fatigue and even gastrointestinal symptoms, according to the CDC. While most people recover in a week or two, flu can cause serious complications, especially in children, older adults, pregnant women and people with other health conditions, such as asthma or cancer.

Last year, an estimated 47 to 82 million Americans became ill with flu, according to the American Hospital Association. At least 600,000 people were hospitalized with flu-related illness, and almost 30,000 people died from flu. Flu season typically peaks in January.

“Flu circulation in Florida is almost year-round, but we’ve seen a sharp increase in the last few weeks,” Rolle says.

Flu is spread person-to-person via coughs and sneezes. It’s also possible to contract the flu by touching surfaces that carry the virus and then by touching one’s mouth, nose or eyes. The virus often spreads among people before they know they are sick.

Flu vaccines are created each year based on information from the strains circulating in the Southern Hemisphere. However, subclade K has mutated quickly and repeatedly this year, according to a report in the medical journal BMJ.

“The CDC identified this strain in August of this year, but it was too late to be included in the vaccine,” Rolle says. “The vaccine was already prepared based on last year’s circulating flu.”

The Southern Hemisphere remains an indicator of how bad the winter flu season may unfold in the Northern Hemisphere. According to Advisory Board, Australia had a particularly severe flu season this year. The last time an H3N2 strain dominated the U.S. flu season was in 2016-17.

While the current flu vaccine is not an ideal match for subclade K, it still offers benefit, says Rolle. Vaccinated individuals are less likely to develop severe cases of the flu. The vaccine also targets other strains of the flu, such as influenza B, that are circulating.

“I tell patients that, regarding of the subclass, it’s important to get vaccinated,” she says. “Whether it’s strain A or B, you are still at risk of hospitalization and secondary infections related to flu. Even if you do get flu after getting vaccinated, it’s likely you will not get as sick as someone who didn’t get vaccinated.”

It’s not too late to get a vaccine, however it takes about two weeks for the body to build up immunity to flu after the vaccine is administered. The CDC recommends annual flu vaccination for everyone 6 months or older. Flu vaccine can be given in a single shot. A nasal flu vaccine is also available for people ages 2 to 49. People with egg allergies can receive a vaccine made using genetic technology. A high-dose flu vaccine flu shot is available for people ages 65 and older.

Most pharmacies offer appointments for flu shots and also accept walk-ins. Flu shots are typically free.

Rolle says patients who are reluctant to receive a vaccine should consider discussing their concerns with their physicians.

“I worry people are choosing not to get vaccinated because of distrust,” she says. “There needs to be a mutual understanding about what [a vaccine] is and what it isn’t.”

Vaccine distrust is leading to the reemergence of once-rare infectious diseases, such as measles and pertussis, that are completely preventable, she notes.

“We’re at risk of having those diseases reemerge again in our communities,” she says. These diseases “are serious and could have been prevented.”

If you do develop flu symptoms, Rolle says, stay home and rest. Flu antiviral medications such as Tamiflu and Xofluza are prescriptions drugs that, when given within one or two days of symptom development, can stop the virus from multiplying and thus lessen the severity of disease. The medications are particularly useful for people who are at increased risk of complications from flu, such as very young children, older adults, pregnant women and people with chronic diseases.

Take care to avoid spreading flu, she adds. “Washing your hands is underutilized,” she says. “It’s one of those things that works so well to reduce the spread of disease.” Masks also help prevent the spread of respiratory droplets from coughs and sneezes, she says.

Rolle also advises some individuals to consider vaccination for respiratory syncytial virus (RSV). The CDC recommends RSV vaccination for everyone ages 75 and older and adults ages 50 to 74 who are at increased risk of severe RSV disease. The vaccine is also recommended for some pregnant women.  

COVID is also still circulating, and vaccines are available to match the strain of COVID that is in circulation.

COVID “may not be at the numbers it once was,” Rolle says. “People are electing not to be tested for it, so it may be circulating a little more than we know of.”