Influenza — what most of us call "the flu" — is a highly contagious viral infection of the respiratory tract.
Flu season runs from October to May. It's best to get a flu vaccine as early in the season as possible, as it gives the body a chance to build up immunity to (protection from) the flu. But getting a flu vaccine later in the season is still better than not getting the vaccine at all.
The Centers for Disease Control and Prevention (CDC) now recommends a flu vaccine for everyone 6 months of age and older (instead of just certain groups, as was recommended before).
But it's especially important that those in higher-risk groups get vaccinated to avoid health problems as a result of the flu. They include:
- all kids 6 months through 4 years old
- anyone 65 years and older
- all women who are pregnant, are considering pregnancy, have recently given birth, or are breastfeeding during flu season
- anyone whose immune system is weakened from medications or illnesses (like HIV infection)
- residents of long-term care facilities, such as nursing homes
- any adult or child with chronic medical conditions, such as asthma
- kids or teens who take aspirin regularly and are at risk for developing Reye syndrome if they get the flu
- caregivers or household contacts of anyone in a high-risk group (like children younger than 5 years old, especially those younger than 6 months, and those with high-risk conditions)
- Native Americans and Alaskan natives
Babies younger than 6 months can't get the vaccine, but if their parents, other caregivers, and older kids in the household get it, that will help protect the baby. This is important because infants are more at risk for serious complications from the flu.
- Kids younger than 9 years old will receive two doses of flu vaccine this flu season if they have received fewer than two doses before July 2015. This includes kids who are getting the flu vaccine for the first time.
- Those under 9 who have received at least two doses of flu vaccine previously (in the same or different seasons) will only need one dose.
- Kids older than 9 need only one dose of the vaccine.
Talk to your doctor about how many doses your child needs.
Types of Vaccines
Different types of vaccines are available. One type (called trivalent) protects against three strains of the flu virus (usually, two types of influenza A viruses and one influenza B virus). Another (called quadrivalent) protects against four strains.
The vaccine can be given to kids in two different ways: by injection with a needle (the flu shot), or sprayed into the nostrils (nasal spray or nasal mist).
Both ways of delivering the vaccine are safe and effective, and experts don't recommend one type over the other, except for kids with certain medical conditions or pregnant women, who should not get the nasal spray.
Some vaccines are approved only for adults at this time, such as egg-free vaccines and intradermal shots, which are injected into the skin (instead of muscle) with a smaller needle.
Vaccine shortages and delays sometimes happen, so check with your doctor about availability and to see which vaccine is right for your kids.
Why the Vaccine Is Recommended
While the flu vaccine isn't 100% effective, it still greatly reduces a person's chances of catching the flu, which can be very serious. It also can make symptoms less severe if someone does still get the flu after immunization.
Even if you or your kids got the flu vaccine last year, that won't protect you this year, because flu viruses constantly change. That's why the vaccine is updated each year to include the most current strains of the virus.
Sometimes the same strains are included in the vaccine one year after the next. In this case, it's still important to get a seasonal flu shot because the body's immunity against the influenza virus declines over time.
Possible Side Effects
Usually given as an injection in the upper arm, the flu shot contains killed flu viruses that will not cause someone to get the flu, but can cause mild side effects like soreness, redness, or swelling at the injection site. A low-grade fever and aches are also possible.
The nasal spray flu vaccine contains weakened live flu viruses, so it may cause mild flu-like symptoms, including runny nose, headache, vomiting, muscle aches, and fever. Very rarely, the flu vaccine can cause a severe allergic reaction.
When to Delay or Avoid Immunization
Certain things might prevent a person from getting the flu vaccine. Talk to your doctor to see if the vaccine is still recommended if your child:
- has ever had a severe reaction to a flu vaccination
- has Guillain-Barré syndrome (a rare condition that affects the immune system and nerves)
In the past, it was recommended that anyone with an egg allergy talk to a doctor about whether receiving the flu vaccine was safe because it is grown inside eggs. But health experts now say that the amount of egg allergen in the vaccine is so tiny that it (but not the nasal mist) is safe even for kids with a severe egg allergy. This is especially important during a severe flu season.
Still, a child with an egg allergy should get the flu shot in a doctor's office, not at a supermarket, drugstore, or other venue. And if the allergy is severe, it might need to be given in an allergist's office.
If your child is sick and has a fever, talk to your doctor about rescheduling the flu shot.
Caring for Your Child After Immunization
A warm, damp cloth or a heating pad at the injection site also may help ease soreness. Moving or using the limb that has received the injection often reduces the soreness as well.
When to Call the Doctor
- you aren't sure if the vaccine should be postponed or avoided
- there are problems after the immunization, such as an allergic reaction or high fever, or if you have other concerns
Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: September 2015
|CDC: Vaccines & Immunizations The CDC's site has information on vaccines, including immunization schedules, recommendations, FAQs, and more.|
|Immunization Action Coalition This organization is a source of childhood, adolescent, and adult immunization information as well as hepatitis B educational materials.|
|CDC: Preteen and Teen Vaccines CDC site provides materials in English and Spanish for parents, teens, preteens, and health care providers about vaccines and the diseases they prevent.|
|CDC: Flu (Influenza) The CDC's site has up-to-date information on flu outbreaks, immunizations, symptoms, prevention, and more.|
|The History of Vaccines The History of Vaccines is an informational, educational website created by The College of Physicians of Philadelphia, the oldest professional society in the United States.|
|Immunization Schedule Which vaccines does your child need to receive and when? Use this immunization schedule as a handy reference.|
|Too Late for the Flu Vaccine? The flu vaccine is usually offered between September and mid-November. Even though it's best to get it then, being vaccinated later can still help protect against the flu.|
|Your Child's Immunizations Immunizations protect your child from potentially fatal diseases. Find out what vaccines your child needs to grow up healthy.|
|Flu Center Learn all about protecting your family from the flu and what to do if your child gets flu-like symptoms.|
|How Many Doses of Flu Vaccine Does My Child Need? Knowing the doctor-recommended flu vaccination schedule can be confusing. Use this tool to help you understand how many doses your child needs.|
|Is the Flu Vaccine a Good Idea for Your Family? The flu vaccine is a good idea for all families. It does not cause the flu, and it helps keep kids and parents from getting sick.|
|Influenza (Flu) Flu symptoms tend to develop quickly and are usually more severe than the typical sneezing and stuffiness of a cold. Yearly vaccination is the best protection against the flu.|
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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