Influenza is noticeably on the rise in King County, according to the many data points coming into our Communicable Disease and Epidemiology unit. Last week, the number of laboratory tests for flu rose sharply and a handful of schools, daycare programs, and long-term care facilities reported flu outbreaks.

A severe flu forecast

The flu season has only just begun, but the CDC is finding that so far, seasonal influenza A H3N2 viruses have been the most common flu viruses circulating. What’s the significance? In flu seasons in which H3N2 viruses predominate, there often are more severe flu illnesses, hospitalizations, and deaths.

On top of that, roughly half of the H3N2 viruses that the CDC analyzed to date are drift variants: viruses with genetic changes that make them different from this season’s vaccine virus. This means the vaccine’s ability to protect against those viruses may be reduced.

So should you still get this year’s flu vaccine?

“Absolutely,” said Dr. Jeff Duchin, Chief of Communicable Disease, Epidemiology and Immunizations. “Some protection is always better than no protection. The vaccine may still reduce the severity of illness if you do get infected with an H3N2 virus. And even if the vaccine is only partially protective against the H3N2, it can protect against other strains of influenza virus that often also circulate during flu season.”

Antivirals: the second line of defense

When people do become ill from the flu, treatment with antiviral medications is available and especially important for people at high risk of serious flu complications or people who are very sick. Antiviral drugs should be taken as quickly as possible since they work best when started within two days from when symptoms began.

Are you at higher risk?

Many people don’t know if they are at high risk for complications from influenza. Some of the people who are at higher risk for complications from influenza include:

• People with asthma
• People with diabetes
• People with heart disease and those who have had a stroke
• Adults 65 and older
• Pregnant women
• People who have HIV or AIDS
• People who have cancer
• People who are morbidly obese
• People with neurodevelopmental/neurocognitive conditions
• Children younger than 5, but especially children younger than 2 years old
• Native Americans/Alaskan Natives

Preventing flu

Flu vaccination is the best protection available, but everyday actions like washing your hands frequently and staying away from sick people definitely help. If you do get sick, please cover your coughs and stay home from work and school. Even if you think you can tough it out, staying home will prevent the virus from spreading further. Your co-workers and friends will thank you, and you can help protect those at high risk from flu.