Influenza Vaccination: A Summary for Clinicians

Who Should Get Vaccinated?

Everyone 6 months of age and older should get an influenza (flu) vaccine every season with rare exception. CDC’s Advisory Committee on Immunization Practices has made this recommendation since the 2010-11 influenza season.

Vaccination to prevent flu is particularly important for people who are at high risk of developing serious flu complications. See People at High Risk of Developing Flu-Related Complications for a full list of age and health factors that confer increased risk.

More information is available at Who Should Get Vaccinated Against Influenza.

What are the influenza vaccine options this season?

Yes. There are different influenza vaccine manufacturers and multiple influenza vaccine products licensed and recommended for use in the United States.

CDC recommends use of any licensed, age-appropriate influenza vaccine during the 2019-2020 influenza season, including inactivated influenza vaccine [IIV], recombinant influenza vaccine [RIV], or live attenuated influenza vaccine (LAIV). No preference is expressed for any influenza vaccine over another. Both trivalent (three-component) and quadrivalent (four-component) influenza vaccines will be available.

Trivalent influenza vaccines include:

Quadrivalent flu vaccines include:

  • Standard-dose quadrivalent influenza shots that are manufactured using virus grown in eggs.  These include Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, and Fluzone Quadrivalent. Different influenza shots are licensed for different age groups. Some are licensed for children as young as 6 months of age. Most influenza shots are given in an arm muscle with a needle. One quadrivalent influenza shot (Afluria Quadrivalent) can be given either with a needle (for people aged 6 months and older) or with a jet injector (for people aged 18 through 64 years only).
  • quadrivalent cell-based influenza shot (Flucelvax Quadrivalent) containing virus grown in cell culture, which is licensed for people 4 years and older. This season, all four of the vaccine viruses used in Flucelvax have been grown in cells, making the vaccine totally egg-free.
  • Recombinant quadrivalent influenza shot (Flublok Quadrivalent), an egg-free vaccine, approved for people 18 years and older.

There are many vaccine options to choose from, but the most important thing is for all people 6 months and older to get an influenza vaccine every year. If you have questions about which vaccine is best for you, talk to your doctor or other health care professional. More information on approved influenza vaccines for the 2019-2020 influenza season, and age indications for each vaccine are available in CDC’s Table: U.S. Influenza Vaccine Products for the 2019-20 Season

Are any of the available flu vaccines recommended over others?

No. For the 2019-2020 influenza season, CDC and its Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for everyone 6 months and older with any licensed age-appropriate influenza vaccine including inactivated influenza vaccine (IIV), recombinant influenza vaccine (RIV4) or live attenuated influenza vaccine (LAIV4) with no preference expressed for any one vaccine over another.

When should I get vaccinated?

You should get a flu vaccine before flu viruses begins spreading in your community, since it takes about two weeks after vaccination for antibodies to develop in the body and provide protection against flu. Make plans to get vaccinated early in fall, before flu season begins. CDC recommends that people get a flu vaccine by the end of October. Getting vaccinated later, however, can still be beneficial and vaccination should continue to be offered throughout the flu season, even into January or later.

Getting vaccinated early (for example, in July or August) is likely to be associated with reduced protection against flu infection later in the flu season, particularly among older adults.

Children who need two doses of vaccine to be protected should start the vaccination process sooner, because the two doses must be given at least four weeks apart.

Vaccination for Children

 

Different influenza vaccines are approved for use in different age groups. In addition, some vaccines are not recommended for certain groups of people. Factors that can determine a person’s suitability for vaccination, or vaccination with a particular vaccine, include a person’s age, health (current and past) and any allergies to influenza vaccine or its components.

Vaccination for Adults

Everyone 6 months of age and older are recommended to get the flu vaccine, including even the healthiest adults. Vaccination is especially important for people at high risk of serious influenza complications or people who live with or care for people at higher risk for serious complications.

Persons working in health care settings also should be vaccinated annually against influenza. Vaccination of health care professionals has been associated with reduced work absenteeism and with fewer deaths among nursing home patients.

People Who Should Not Be Vaccinated

People who have had a severe reaction to an influenza vaccination, and children younger than 6 months of age should not be vaccinated.

People who are moderately or severely ill with or without fever should usually wait until they recover before getting flu vaccine.

A history of Guillain-Barré Syndrome (GBS) within 6 weeks following receipt of influenza vaccine is a precaution for the use of influenza vaccine. Such individuals have a risk of recurrence of GBS with subsequent vaccination, and if not at high risk of severe influenza complications should generally not be vaccinated. However, while data are limited, the established benefits of influenza vaccination might outweigh the risks for many people who have a history of GBS and who also are at high risk for severe complications from influenza.

See Table 1: Influenza vaccines, contraindications and precautions in the 2016-2017 ACIP Influenza Vaccine Recommendations for more information.

Different influenza (flu) vaccines are approved for use in different age groups. In addition, some vaccines are not recommended for certain groups of people. Factors that can determine a person’s suitability for vaccination, or vaccination with a particular vaccine, include a person’s age, health (current and past) and any allergies to flu vaccine or its components.

Vaccination of People with a History of Egg Allergy

Most influenza vaccines are produced by growing influenza virus in embryonated chicken eggs, and therefore contain trace amounts of egg protein. See Persons with a History of Egg Allergy for complete information and an algorithm to guide decision-making for vaccination of persons with egg allergy.

All vaccines should be administered in settings in which personnel and equipment for rapid recognition and treatment of anaphylaxis are available.

A previous severe allergic reaction to influenza vaccine, regardless of the component suspected to be responsible for the reaction, is a contraindication to future receipt of the vaccine.

Special Consideration Regarding Egg Allergy

People with egg allergies can receive any licensed, recommended age-appropriate influenza (flu) vaccine (IIV, RIV4, or LAIV4) that is otherwise appropriate.  People who have a history of severe egg allergy (those who have had any symptom other than hives after exposure to egg) should be vaccinated in a medical setting, supervised by a health care provider who is able to recognize and manage severe allergic reactions.

Influenza Vaccines and Use of Influenza Antiviral Medications
  • Administration of inactivated influenza vaccine to persons receiving influenza antiviral drugs for treatment or chemoprophylaxis is acceptable.
  • Live-attenuated influenza vaccine should not be administered until 48 hours after cessation of influenza antiviral therapy.
  • If influenza antiviral medications are administered within 2 weeks after receipt of live-attenuated influenza vaccine, the vaccine dose should be repeated 48 or more hours after the last dose of antiviral medication.
Concurrent Administration of Influenza Vaccine With Other Vaccines
  • Inactivated vaccines do not interfere with the immune response to other inactivated vaccines or to live vaccines.
  • Inactivated or live vaccines can be administered simultaneously with live-attenuated influenza vaccine.
  • However, after administration of a live vaccine, at least 4 weeks should pass before another live vaccine is administered.
For Your Patients

VIS are information sheets produced by CDC that explain both the benefits and risks of a vaccine to vaccine recipients.