Frequently Asked Questions About Influenza

(often called the flu)

 

 


City of Berkeley Public Health Division
1947 Center Street, Second Floor, Berkeley, CA 94704
Map to Public Health Division

510-981-5300 (Phone)   510-981-5395 (Fax)   510-981-6903 (TDD)
PublicHealth@cityofberkeley.info

Monday - Friday: 8:00am - 5:00pm


What is influenza?

How does the flu spread?

What are the symptoms of the flu?

Who should get influenza vaccine?

When should I get influenza vaccine?

Will the vaccine keep me from getting influenza this year?

Can I get the flu from the flu shot?

Can other vaccines be given at the same time?

What are the risks from influenza vaccine?

What if I have symptoms after I get the shot?


 

What is Influenza (often called the flu)?
The flu is a virus and can be a serious disease. Influenza can make people of any age ill. Although most people are ill for only a few days, some have a much more serious illness and may need to be hospitalized. Thousands of people die each year from influenza-related illnesses. Most deaths caused by influenza are in elderly people.


How does the flu spread? 
It spreads when influenza viruses pass from an infected person to the nose or throat of another person.
The flu is often confused with the common cold. Flu symptoms start quickly (usually 1 to 4 days after a person is exposed to the flu virus). 

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The symptoms of flu are: 
Fever, chills, headache, cough, sore throat, and muscle aches.

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Who should get influenza vaccine (often called the flu shot)?

  • All persons aged 6 months and older should be vaccinated annually, with rare exceptions.
  • Individuals aged 2-49 with underlying chronic medical conditions.
  • All women who will be pregnant during influenza season.
  • Residents of nursing homes and long-term care facilities.
  • Children 6 months to 18 years of age on chronic aspirin therapy.
  • Out-of-home caregivers and household contacts of persons belonging to any of the priority groups listed above.
  • Out-of-home caregivers and household contacts of children less than 6 months of age.
  • Healthcare workers involved with direct patient care.
  • Emergency service workers, such as law enforcement, firefighters and paramedics.
  • Anyone who wants to get a flu shot to protect themselves from the flu.

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When should I get influenza vaccine?
Influenza is most common in the U.S. from December to April, so it is best to get the vaccine in the fall. The best time to get the influenza vaccine is mid- September to mid-November. It takes about 2 weeks for the vaccine to develop immunity in the body and provide protection.

People 9 years and older need one shot each influenza season, while children less than 9 years old may need a second shot after one month. The viruses that cause influenza change often, and protection declines within a year after vaccination. So people who need the vaccine should get it every year. 

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Will the vaccine keep me from getting influenza this year? 
No.  Since influenza viruses change frequently, they may not always be covered by the vaccine. Also, other viruses cause diseases that seem like influenza, and the influenza vaccine does not protect against these viral infections. The vaccine contains viruses that are the same or similar to those thought to be most likely to come to the U.S. this year.

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Can I get the flu from the flu shot?
No. All the viruses in the vaccine are killed so you cannot get influenza from the vaccine. 

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Can other vaccines be given at the same time? 
Yes, but in a different arm. These include:

  • Pneumococcal vaccine
  • All childhood vaccines  

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What are the risks from influenza vaccine?
As with any medicine, there are very small risks that serious problems could occur after taking the vaccine. But the risks from the vaccine are much smaller than the risks from the disease itself. Almost all people who get influenza vaccine have no serious problem from it. 

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What if I have symptoms after I get the shot?
Most people will experience no side effects from the influenza vaccine. Only one out of three people who receive the vaccine will have some soreness at the vaccination site, and about 5% to 10% will experience a headache or a mild fever. The most serious side effect that can occur after an influenza vaccination is an allergic reaction in individuals who have a severe allergy to eggs. For that reason, people who have an allergy to eggs should not receive the influenza vaccine.

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If mild or moderate problems occur, they usually start soon after the vaccination and usually last up to 1-2 days. 
These may include:

  • soreness, redness, or swelling where the shot was given
  • fever
  • aches

Tell your doctor or nurse if you:

  • have a serious allergy to eggs.
  • Ever had a serious allergic reaction or other problem after getting influenza vaccine.
  • Were ever paralyzed with Guillain-Barré Syndrome.
  • Now have a moderate or severe illness.


What to do if there is a serious reaction:

  • Call a doctor or get the person to a doctor right away.
  • Write down what happened and the date and time it happened.
  • Ask the doctor, nurse or health department to file a Vaccine Adverse 

For more information about seasonal influenza:

http://www.cdc.gov/flu/index.htm

For information on Avian Influenza, including guidance for clinicians:

http://www.dhs.ca.gov/ps/dcdc/VRDL/html/FLU/H5N1/Main Avian Flu page.htm

http://www.cdc.gov/flu/avian/

For information on Pandemic Influenza:

http://www.pandemicflu.gov/



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