No one wants to get sick — but especially while they’re on vacation! Disney World might be the Most Magical Place on Earth, but it also can be a hotbed for germs.

There’s a new flu strain going around right now, called “subclade K,” and it’s spreading pretty rapidly ahead of the official flu season. If you’ve got upcoming travel plans to Disney World or otherwise — here’s what you need to know.

Flu season isn’t quite in full effect in the United States just yet, but that hasn’t stopped a new strain of the virus from spreading, according to TODAY. A new version of influenza A H3N2 is potentially vaccine-resistant due to its genetic mutations.

The mutated H3N2 strain, known as “subclade K,” has spread rapidly throughout countries in the Northern hemisphere, including Japan and the United Kingdom. Japan declared an influenza epidemic following the surge, and U.K. health officials have warned this could be one of the worst winters yet as the strain spreads.

In addition, the virus has been spreading in Canada, which has caused scientists to warn about a potential mismatch between the H3N2 in the current 2025-2026 flu vaccine and the subclade K strain. It’s now projected to become the dominant strain worldwide.

H3N2 subclade K has already been detected in more than half of U.S. states so far, per the Global Initiative on Sharing All Influenza Data (GISAID) database. Lags in data from the Centers for Disease Control (CDC) have made it difficult to track trends in real time, according to experts.

According to the CDC’s latest “FluView” surveillance report from the week of November 22nd, flu activity remains low nationally, but cases are increasing. H3N2 is considered more severe across all age groups, but especially among the elderly and young children. So far, no flu-related deaths have been reported in the U.S.

As of December 4th, instances of subclade K have been submitted to GISAID from at least 29 states and Washington, D.C., including:

• Alaska
• California
• Colorado
• Connecticut
• Delaware
• Florida
• Hawaii
• Indiana
• Iowa
• Louisiana
• Maryland
• Massachusetts
• Michigan
• Minnesota
• Missouri
• Montana
• New Jersey
• New York
• North Carolina
• North Dakota
• Ohio
• Oklahoma
• Pennsylvania
• South Carolina
• Texas
• Vermont
• Virginia
• Washington
• Wisconsin

The strain mutated too late for scientists to update this season’s flu vaccine, though it will still offer protection throughout flu season and is especially important for high-risk individuals — the elderly, young children, pregnant women, and immunocompromised persons.

The symptoms of the subclade K strain include:

• Fever
• Chills
• Body aches
• Headache
• Extreme fatigue
• Congestion or runny nose
• Coughing

So, what can you do if you’re traveling during flu season? In addition to getting the flu vaccine, the CDC recommends you:

• Test if you have symptoms.
• If positive, isolate for 24 hours or until you’re fever-free.
• Avoid sick people.
• Wear a mask in crowded, indoor spaces.
• Wash your hands frequently.
• Cover coughs and sneezes.

If you’re flying, wear a mask in the airport and on the plane — studies have shown that this can decrease your chances of getting infected drastically. Wash your hands regularly or use hand sanitizer when that might not be an option, and consider bringing disinfecting wipes with you to wipe down surfaces on planes and in your hotel room.

If you start feeling sick at Disney World, you should head back to your hotel room to rest — and to stay away from other people. This can help prevent the spread. Keep in mind that Disney World has first aid centers, and the Cast Members there can help you and give you advice on what to do.

There are also tons of virtual options available in the My Disney Experience App that can assist you with a multitude of different issues. You’ll find options such as Athletic Training resources, runDisney resources, Emergency Room resources, Urgent Care and Virtual Care, a Care Concierge Call Center, Vacation Planning resources, and Equipment and Prescription Delivery.

If you do need to go to an Urgent Care, complimentary transportation to the AdventHealth Centra Care Urgent Care, located INSIDE Disney World property at 12500 S. Apopka Vineland Rd, Lake Buena Vista, Florida, is offered to Disney World Resort guests. To organize transport, contact First Aid, Resort Front Desk Cast Members, or call AdventHealth at (407) 939-7480.

We’ll be on the lookout for the latest updates about this flu strain and how it may impact your trip to Disney World. In the meantime, make sure you stay tuned to the Disney Food Blog for the latest Disney news and beyond.

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Are you planning an upcoming trip to Disney World? Let us know in the comments below.