Seasonal Flu Vaccine Recommendations^1,2,4

An annual seasonal flu vaccine is the best way to help protect against flu.

The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season.

The CDC recommends that everyone ages 6 months and older get a seasonal flu vaccine every season. Vaccination is particularly important for children who are at especially high risk of serious flu-related complications

• Children younger than 5 years of age, and especially children younger than 2 years of age
• Children of any age with a chronic health condition such as asthma, diabetes, or heart disease

The flu vaccine is recommended for household contacts and caregivers of children younger than 5 years of age, with particular emphasis on vaccinating contacts of children aged younger than 6 months.

Vaccination is also recommended for household contacts and caregivers of children with medical conditions that put them at high risk of severe complications from influenza. 

All PHCA locations offer flu vaccine for parents in our offices - please ask your pediatrician for information at your next visit. 

Vaccine Types and Protection¹

Flu Vaccine - Injection: Inactivated influenza vaccine given with a needle, usually in the arm (muscle). The flu shot is recommended for use in people older than 6 months, including healthy people, people with chronic medical conditions, and pregnant women.

Patients who can't get the flu shot:

• Children younger than 6 months of age (flu vaccine is not approved for this age group)
• Children with severe, life-threatening allergies to flu vaccine or any ingredient in the vaccine. This might include gelatin, antibiotics, or other ingredients. Please visit "Flu Vaccine and People with Egg Allergies" for more information regarding egg allergies and flu vaccine.

Patients who should talk to their pediatrician before getting the flu shot:

• Children who have an allergy to eggs or any of the ingredients in the vaccine. See link above for additional information about egg allergies and flu vaccine.
• Some children with a history of Guillain-Barre Syndrome (GBS) should not receive flu vaccine. Talk to your pediatrician about your child's GBS history.
• Children who have a moderate-to-severe illness with a fever should wait until they recover before getting vaccinated.

Special Instructions: Children Ages 6 Months to 8 Years²

• Some children 6 months to 8 years of age require two doses of flu vaccine:
  • Children in this age group getting vaccinated for the first time
  • Children in this age group who have previously received only one dose of flu vaccine
• The first dose should be given as soon as vaccine becomes available
• The second dose should be given at least 28 days after the first dose
• If your child needs the two doses, it begin the process early. This will ensure you child is protected before influenza begins circulating in your community.
• Be sure to get your child a second dose if one is needed. It usually takes about two weeks after the second dose for protection to begin.

NOTE: All children who have previously received two doses of influenza vaccine (at any time) only need one dose of vaccine this season. 

When to Get Vaccinated¹

CDC recommends that people get their seasonal flu vaccine as soon as vaccine becomes available, if possible by the end of October. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection agains the flu. Vaccination later in the flu season can still be beneficial, even into January or later for protective benefit.

Vaccine Benefits³

• Flu vaccination can keep you from getting sick from flu.
• Flu vaccine can be life-saving in children. A 2017 study was the first of its kind to show that flu vaccination can significantly reduce a child's risk of dying from influenza.
• Flu vaccination can help protect people around you, including those who are more volnerable to seriously flu illness, like babies and young children (especially infants younger than 6 months old who are too young to get vaccinated), older people, and people with certain chronic health conditions.
• Flu vaccination can reduce the risk of flu-associated hospitalizations.
  • A 2014 study** showed that flu vaccine reduced children’s risk of flu-related pediatric intensive care unit (PICU) admission by 74% during flu seasons from 2010-2012.
  • A 2018 study showed that from 2012-2015, flu vaccination among adults reduced the risk of being admintted to an intensive care unit (ICU) with flu by 82%.
• Flu vaccination helps protect women during and after pregnancy. A number of studies have shown  that a flu vaccine given during pregnancy helps protect the baby from flu infection for several months after birth, when baby is not old enough to be vaccinated.
• Flu vaccination can reduce severity of illness in people who get vaccinated but still get sick.

Vaccine Effectiveness³

CDC conducts studies each year to determine how well the flu vaccine protects against flu illness. While vaccine effectiveness can vary, recent studies show vaccine reduces the risk of flu illness by between 40% to 60% among the overall population during seasons when most circulating flu viruses are well-matched to the flu vaccine.

How well the flu vaccine works (or its ability to prevent flu illness) can range widely from season to season. The vaccine’s effectiveness also can vary depending on who is being vaccinated. At least two factors play an important role in determining the likelihood that flu vaccine will protect a person from flu illness: 1) characteristics of the person being vaccinated (such as their age and health), and 2) the similarity or "match" between the flu viruses the flu vaccine is designed to protect against and the flu viruses spreading in the community. During years when the flu vaccine is not well matched to circulating viruses, it’s possible that no benefit from flu vaccination may be observed. During years when there is a good match between the flu vaccine and circulating viruses, it’s possible to measure substantial benefits from vaccination in terms of preventing flu illness. However, even during years when the vaccine match is very good, the benefits of vaccination will vary across the population, depending on characteristics of the person being vaccinated and even, potentially, which vaccine was used.

Possible Vaccine Side Effects¹

A flu vaccine cannot cause flu illness.

Flu vaccines that are administered with a needle are currently made in two ways: the vaccine is made either with a) flu vaccine viruses that have been killed (inactivated) and are therefore not infectious, or b) with proteins from a flu vaccine virus instead of flu vaccines viruses (which is the case for recombinant influenza vaccine).

The nasal spray flu vaccine does contain live viruses. However, the viruses are attenuated (weakened), and therefore cannot cause flu illness. The weakened viruses are cold-adapted, which means they are designed to only cause infection at the cooler temperatures found within the nose. The viruses cannot infect the lungs or other areas where warmer temperatures exist.

While a flu vaccine cannot give you flu illness, there are side effects that may be associated with getting a flu vaccine. These side effects are mild and short-lasting, especially when compared to symptoms of bad case of flu.

The flu shot: The viruses in the flu shot are killed (inactivated), so you cannot get the flu from a flu shot. Some minor side effects that may occur are:

• Soreness, redness, or swelling where the shot was given
• Fever (low grade)
• Aches

If these problems occur, they begin soon after vaccination and are mild and short-lived. Almost all people who receive influenza vaccine have no serious problems from it. However, on rare occasions, flu vaccination can cause serious problems, such as severe allergic reactions. 

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Information compiled from CDC sources | Updated February 04, 2025

CDC Sources:

2025 Summary of Recommendations of the Advisory Committee on Immunization Practices (ACIP)
Key Facts About Seasonal Flu Vaccine
Children & Influenza (Flu)
Vaccine Effectiveness - How Well Do the Flu Vaccines Work?