• Introduction:

    Influenza (flu) is a contagious disease that can be serious. Every year, millions of people get sick, hundreds of thousands are hospitalized, and thousands to tens of thousands of people die from flu.

Influenza (flu) Faq

Influenza (flu) is a contagious disease that can be serious. Every year, millions of people get sick, hundreds of thousands are hospitalized, and thousands to tens of thousands of people die from flu.

Taking Temperature

Who is most likely to be infected with influenza?

The same CID study found that children are most likely to get sick from flu and that people 65 and older are least likely to get sick from influenza. Median incidence values (or attack rate) by age group were 9.3% for children 0-17 years, 8.8% for adults 18-64 years, and 3.9% for adults 65 years and older. This means that children younger than 18 are more than twice as likely to develop a symptomatic flu infection than adults 65 and older.

How is seasonal incidence of influenza estimated?

Influenza virus infection is so common that the number of people infected each season can only be estimated. These statistical estimations are based on CDC-measured flu hospitalization rates that are adjusted to produce an estimate of the total number of influenza infections in the United States for a given flu season.

The estimates for the number of infections are then divided by the census population to estimate the seasonal incidence (or attack rate) of influenza.

Does seasonal incidence of influenza change based on the severity of flu season?

Yes. The proportion of people who get sick from flu varies. A paper published in CID found that between 3% and 11% of the U.S. population gets infected and develops flu symptoms each year. The 3% estimate is from the 2011-2012 season, which was an H1N1-predominant season classified as being of low severity. The estimated incidence of flu illness during two seasons was around 11%; 2012-2013 was an H3N2-predominant season classified as being of moderate severity, while 2014-2015 was an H3N2 predominant season classified as being of high severity.


Influenza (flu) Frequently Asked Questions

ALL persons 6 months of age and older should be vaccinated. Persons especially at risk include the elderly, those with chronic illness, infants, and pregnant women. Health care workers, caregivers of high-risk individuals, and persons with contact with infants younger than 6 months are also strongly encouraged to be vaccinated.

Public Health offers preservative free quadrivalent and high-dose influenza vaccine.

Public Health bills all commercial insurances as well as Medicare and Medicaid. There is no office visit co-pay for immunization services. For self-pay patients the fee for adult vaccine is $21.00, high-dose vaccine $32.00, and for persons 6 months-18 years $12.00. Free vaccine is available for persons without insurance that cannot afford to pay.

No! The flu is far more dangerous, even in healthy people.

Although many people with influenza have mild illness, every year some people become very sick and need to be hospitalized, or even die. Getting a flu vaccine is the best protection against the flu and these serious complications.

No! The flu vaccine cannot give you the flu.

Flu vaccines may cause mild muscle aches and a low fever. These discomforts are brief and are signs that the vaccine is teaching your body how to protect itself against the flu. If you are exposed to the flu after vaccination, your body will be better prepared to fight the virus, and you will be less likely to become very sick and be hospitalized.

One of the following may have happened:

  • A different virus may be going around. The flu vaccine protects against common types of the flu. It does not protect against other infections like COVID-19.
  • You may have become sick with the flu before the vaccine had time to work. It takes about two weeks to be fully protected from the flu after vaccination.
  • No vaccine is 100% effective. However, if you do get the flu after vaccination, you are less likely to become seriously ill.

Yes! Protection from last year’s vaccine wears off with time, so you will need another dose of vaccine to protect yourself this year.

Flu viruses also change over time. The vaccine you receive this year will provide the best protection against the most likely types of flu viruses you may be exposed to in the community.

Yes! Flu vaccines have been around for over 50 years.

The production and safety of flu vaccines are closely monitored by the CDC and the FDA. According to the CDC, hundreds of millions of flu vaccines have been given safely.

Yes! The flu vaccine can be administered during the same visit as COVID-19 vaccines or boosters.

Different injection sites will be used to administer the vaccines. The flu vaccine will provide protection against the flu virus, and the COVID vaccine will provide protection against the virus that causes COVID-19 infections.

No! Flu seasons are unpredictable.

They can begin in early fall and last into spring. It’s never too late to protect yourself, your family and friends, and your community!