Flu cases are on the rise, and experts are sharing tips on how to protect your family from illness this holiday season.
According to the latest available Centers for Disease Control and Prevention flu report ending the week of Dec. 13, the agency estimates there have been over 4.6 million cases of the flu across the U.S., with at least 49,000 hospitalizations and 1,900 deaths this flu season already, and cases are expected to rise over the holidays.
Multiple states including Colorado, Louisiana and New York have been hit hard with flu cases, per CDC data.
Some schools had to deal with the spike in cases by switching to remote learning or closing schools early, ahead of scheduled breaks.
In Dexter, Kansas, Dexter Schools USD #471 announced earlier this month that it would close early for winter break, after approximately 25% to 35% of its students called out sick.
The dominant flu strain circulating this season is the new subclade K variant, which experts say may be contributing to an early increase in flu cases abroad, including in the United Kingdom.
Subclade K is a variant of the H3N2 influenza virus that has been circulating since the summer months in other countries.
The CDC notes that those who are most vulnerable to the flu overall include adults over 65, children under the age of 5, anyone who is immunocompromised, pregnant people, and people with underlying chronic conditions such as diabetes, heart disease or lung disease.
According to the CDC, symptoms of the flu, including the subclade K flu strain, may include fever, chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, fatigue, or vomiting and diarrhea, although gastrointestinal symptoms may be more common in children than adults.
Although the new subclade K variant does not fully match this season's flu vaccine, doctors and the CDC still recommend everyone over the age of 6 months get the vaccine as a protective measure. Children between the ages of 6 months to 8 years of age who have not received the flu vaccine previously may require at least two doses, at least four weeks apart.
"Data from the U.K. shows us that the vaccine can decrease hospitalizations in kids by about 70-75%, in adults by about 30-40%," ABC News chief medical correspondent Dr. Tara Narula previously said on "Good Morning America."
"[It's] really important for people to get the vaccine, especially before travel coming up," Narula added, noting that "it takes about two weeks to build up those antibodies."
Separately, the CDC notes there are prescription antiviral medications that can treat flu, and they work best when started as early as possible, especially for people at higher risk.
AAA estimates that more than 122 million Americans will hit the roads and take to the skies between Dec. 20 and Jan. 1.
On "GMA," ABC News transportation correspondent Gio Benitez shared several tips for staying healthy during the holiday rush that he has learned from years of traveling and speaking with experts across the country:
