NYC Influenza Information
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Facts about Vaccines for Seasonal Influenza

Printable version (PDF - 8/26/10)

Who should get a seasonal influenza vaccine?

Influenza viruses change every year and it is important to get the vaccine yearly to help prevent complications from influenza infection. Everyone six months of age and older is recommended to get flu vaccine, but vaccination is especially important for people in the following groups:

  • Pregnant women
  • All health care workers
  • Anyone 6 months through 18 years of age
  • Anyone 19 through 49 years of age who has an underlying health condition that increases the risk of complications from influenza (see box)
  • Adults 50 and older
  • Anyone who lives with or cares for infants under 6 months of age
Health conditions that increase the risk of influenza complications
  • Asthma and other chronic respiratory conditions
  • Heart, kidney or liver disease
  • Hematologic diseases, such as sick cell anemia 
  • Metabolic disorders, such as diabetes 
  • Weakened immune system, from illness or medication 
  • Neuromuscular disorders that interfere with breathing or the
    discharge of mucus 
  • Pregnancy 
  • Long-term aspirin therapy in people under 19
What is the difference between the flu shot and the nasal-spray vaccine?

The shot is made from killed influenza virus that alerts the body's defenses when injected into a muscle. The nasal spray contains live but weakened influenza virus that survives long enough in the nostrils to provoke that same response. Healthy people between the ages of 2 and 49 can receive the vaccine in either form. However, pregnant or breastfeeding women, babies less than 2 years old, and people with long-term health conditions should receive only the shot, not the nasal spray. Talk to your doctor to determine which is best for you.

When should I get my influenza vaccine?

Influenza viruses are always changing. To maintain your protection, you need a different vaccine each year. The vaccine starts to protect you after one to two weeks. Influenza is most common in the United States from December to April. It is best to get vaccinated in the fall, but you can be vaccinated through late spring. People 9 years of age and older need only one seasonal influenza vaccine each year. Children less than 9 years old may need two doses of vaccine, given at least four weeks apart, depending on their vaccination history. Your child’s doctor can provide you with more information.

Where can I receive the seasonal flu vaccine?

Primary-care doctors will offer the seasonal vaccine. Check to see if your regular health care provider has them. If you don’t have a regular doctor, you can call 311 or go to As the vaccine supply increases, public clinics and commercial pharmacies will also offer the seasonal flu vaccine vaccine.

Will the vaccines keep me from getting influenza this year?

The seasonal flu vaccine protects against several of the most common strains of influenza that could circulate this fall and winter. Because new influenza viruses appear every year, the effectiveness of the vaccine varies from one year to the next. But even when a vaccine doesn't provide complete protection, people who are vaccinated tend to experience milder illness, and less hospitalization, than others. Other viruses can cause influenza-like illness, and influenza vaccines do not protect against these infections. You cannot get influenza from the killed or weakened viruses used in vaccines.

Can other vaccines be given at the same visit?

Yes, children can receive all routinely scheduled vaccines along with
the flu shot.

What are the risks from influenza vaccine?

The risk of harm from influenza vaccines is much smaller than the risk from the disease. Serious vaccine side effects are possible but extremely rare. Most side effects are mild and last one to two days. The most common ones are fever, aches, and swelling or soreness at the site of the injection.

  • 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
  • Are currently feeling sick
What to do if someone experiences 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 Event Report form (, 800-822-7967, or 212-676-2288).

For additional information or to find out where you can get vaccinated, call 311 or visit

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