Influenza Vaccination: A Summary for Clinicians

Who Should Be Vaccinated?

Everyone 6 months and older in the United States should get an influenza (flu) vaccine every season with rare exception. CDC’s Advisory Committee on Immunization Practices has made this “universal” recommendation since the 2010-2011 flu season.

Vaccination to prevent flu and its potentially serious complications is particularly important for people who are at higher risk of developing serious flu complications. A full list of age and health factors that confer increased risk is available at People at Higher Risk of Developing Flu-Related Complications.

More information is available at Who Needs a Flu Vaccine.

What are the influenza vaccine options this season?

For people younger than 65 years, CDC does not preferentially recommend any licensed, age-appropriate influenza (flu) vaccine over another during the 2022-2023 flu season. Options for this age group include inactivated influenza vaccine [IIV], recombinant influenza vaccine [RIV], or live attenuated influenza vaccine (LAIV), with no preference for any flu vaccine over another.

New for this season: For people 65 years and older, there are three flu vaccines that are preferentially recommended over standard-dose, unadjuvanted flu vaccines. These are Fluzone High-Dose Quadrivalent vaccineFlublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine. More information is available at Flu & People 65 Years and Older.

All flu vaccines for the 2022-2023 season are quadrivalent vaccines, designed to protect against four different flu viruses, including two influenza A viruses and two influenza B viruses. Different vaccines are licensed for use in different age groups, and some vaccines are not recommended for some groups of people.

Available flu vaccines include:

  • Standard-dose flu shots that are manufactured using virus grown in eggs. Several different brands of standard dose flu shots are available, including Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, and Fluzone Quadrivalent. These vaccines are approved for use in children as young as 6 months. Most flu shots are given in the arm (muscle) with a needle. Afluria Quadrivalent can be given either with a needle (for people 6 months and older) or with a jet injector (for people 18 through 64 years only).
  • cell-based flu shot (Flucelvax Quadrivalent) containing virus grown in cell culture, which is approved for people 6 months and older. This vaccine is completely egg-free.
  • recombinant flu shot (Flublok Quadrivalent) which is a completely egg-free flu shot that is made using recombinant technology and is approved for use in people 18 years and older. This shot is made without flu viruses and contains three times the antigen (the part of the vaccine that helps your body build up protection against flu viruses) than other standard-dose inactivated flu vaccines, to help create a stronger immune response.
  • An egg-based high dose flu shot (Fluzone High-Dose Quadrivalent), which is approved for use in people 65 years and older. This vaccine contains four times the antigen (the part of the vaccine that helps your body build up protection against flu viruses) than other standard-dose inactivated flu vaccines, to help create a stronger immune response.
  • An egg-based adjuvanted flu shot (Fluad Quadrivalent), which is approved for people 65 years and older. This vaccine is made with an adjuvant (an ingredient that helps create a stronger immune response).
  • An egg-based live attenuated flu nasal spray vaccine (FluMist Quadrivalent) made with attenuated (weakened) live flu viruses, which is approved for use in people 2 years through 49 years. This vaccine is not recommended for use in pregnant people, immunocompromised people, or people with certain medical conditions.

Are any of the available influenza vaccines recommended over others?

Yes, for some people. There are three flu vaccines that are preferentially recommended for people 65 years and older. These are Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine. This recommendation was based on a review of available studies which suggests that, in this age group, these vaccines are potentially more effective than standard dose unadjuvanted flu vaccines. There is no preferential recommendation for people younger than 65 years.

What if a preferentially recommended flu vaccine is not available?

If none of the three flu vaccines preferentially recommended for people 65 years and older is available at the time of administration, people in this age group should get any other age-appropriate flu vaccine instead.

When should I get vaccinated?

For most people who need only one dose of flu vaccine for the season, September and October are generally good times to be vaccinated against flu. Ideally, everyone should be vaccinated by the end of October. Additional considerations concerning the timing of vaccination for certain groups of people include:

  • Most adults, especially those 65 years and older, and pregnant people in the first or second trimester should generally not get vaccinated early (in July or August) because protection may decrease over time. However, early vaccination can be considered for any person who is unable to return at a later time to be vaccinated.
  • Some children need two doses of flu vaccine. For those children it is recommended to get the first dose as soon as vaccine is available, because the second dose needs to be given at least four weeks after the first. Vaccination during July and August also can be considered for children who need only one dose.
  • Vaccination during July and August also can be considered for people who are in the third trimester of pregnancy during those months, because this can help protect their infants for the first few months after birth (when they are too young to be vaccinated).

Vaccination for Children

Children 6 months of age and older are recommended to get an annual influenza vaccine. Children younger than 5 years old—especially those younger than 2—are at higher risk of developing serious influenza-related complications. An influenza vaccine is the best way to reduce the risk of getting sick with flu and developing any of the potentially that can result. Flu vaccination also can reduce the spread of flu to others.

Children can get vaccinated as soon as flu vaccines become available—even if this is in July or August. Children 6 months to 8 years of age receiving their first influenza vaccine, who have not previously received a total of two or more doses in their lives, or whose influenza vaccination history is unknown need two doses. For those children it is recommended to get the first dose as soon as vaccine is available, because the second needs to be given at least four weeks after the first.

For more information visit Flu & Young Children.

Vaccination for Adults

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

Different influenza (flu) vaccines are approved for use in people 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. More information is available at Who Should and Who Should NOT get a Flu Vaccine.

Recommendations for Vaccination of Persons with Egg Allergy

People with egg allergy may receive any vaccine (egg-based or non-egg-based) that is otherwise appropriate for their age and health status. Previously, it was recommended that people with severe allergy to egg (those who have had any symptom other than hives with egg exposure) be vaccinated in an inpatient or outpatient medical setting. Beginning with the 2023-2024 season, additional safety measures are no longer recommended for flu vaccination of egg-allergic persons beyond those recommended for receipt of any vaccine, regardless of the severity of previous reaction to egg. All vaccines should be administered in settings in which personnel and equipment needed for rapid recognition and treatment of allergic reactions are available.

People with Allergies to Vaccine Components, or Allergic Reactions to Influenza Vaccines

A previous severe allergic reaction to a component of an influenza vaccine (with the exception of egg protein) is a contraindication to receipt of that vaccine and vaccines containing that component.  Vaccine components can be found in package inserts.

For people who have had an allergic reaction to a previous dose of an influenza vaccine, future receipt of that vaccine is contraindicated. For other influenza vaccines, there will either be a contraindication or a precaution to future receipt. Whether another influenza vaccine has a contraindication or precaution depends upon what vaccine was associated with the severe allergic reaction. Current ACIP recommendations has further guidance. If vaccination is elected when a precaution is present, it should occur in a medical setting under supervision of a provider who can recognize and manage a severe allergic reaction. Providers can also consider consultation with an allergist in such cases to help identify the vaccine component responsible for the severe allergic reaction.

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.

Use of LAIV4 for persons who are receiving or who have recently received influenza antiviral medications has not been studied. However, influenza antiviral medications might interfere with the action of LAIV4 because this vaccine contains live influenza viruses.  The exact period of time during which this might occur is not known. Based upon the half-lives of the different medications, interference might be possible

    • From 48 hours before to two weeks after LAIV4 administration for oseltamivir and zanamivir,
    • From 5 days before to two weeks after LAIV4 administration for oseltamivir and peramivir, and
    • From 17 days before to two weeks after LAIV4 administration for baloxavir

People who receive these medications during these periods before or after receipt of LAIV4 should be revaccinated with another appropriate influenza vaccine. Time periods for which interference might be possible could be longer than those listed in the setting of medical conditions that delay clearance of medications.

Concurrent Administration of Influenza Vaccine with Other Vaccines

Inactivated and recombinant influenza vaccines may be administered concurrently or sequentially with other live or inactivated vaccines. Injectable vaccines given simultaneously should be administered at separate anatomic sites.

LAIV4 may be administered simultaneously with other inactivated or live vaccines. If not given simultaneously, then LAIV4 and other live vaccine should be spaced at least 4 weeks apart.

Current guidance for the use of COVID-19 vaccines states that these vaccines may be administered with influenza vaccines.  Providers should refer to current CDC and Advisory Committee on Immunization Practices (ACIP) recommendations and guidance for the use of COVID-19 vaccines  for up-to-date information on administration of these vaccines with other vaccines.

What is CDC’s Position on Mandating Flu Vaccination for Health Care Workers?

The findings of a CDC review of related published literature indicate that influenza vaccination of health care personnel can enhance patient safety. 1,2

CDC conducts science-based investigations, research, and public health surveillance both nationally and internationally. CDC adopts recommendations that are made by the Advisory Committee for Immunization Practices. These recommendations may be considered by state and other Federal agencies when making or enforcing laws. CDC also has infection control recommendations for health care settings. However, CDC does not issue any requirements or mandates for state agencies, health systems, or health care workers regarding infection control practices, including influenza vaccination or the use of masks.

Some employers require certain immunizations. Hospitals, for example, may require some staff to get a flu vaccine or hepatitis B vaccine or take other precautions such as the use of masks.

To find out more about the laws in your state and  to contact your state health department through Public Health Resources: State Health Departments.

State Immunization Laws for Healthcare Workers and Patients and Vaccines and Immunizations: Basics and Common Questions National Center for Immunization and Respiratory Diseases have more information. For more information, updates, and access to free materials to assist with educating staff and patients about the impact of influenza and the benefits of vaccination, visit CDC Seasonal Influenza (Flu) or call the National Immunization Hotline at (800) 232-2522 (English), (800) 232-0233 (Español), or (800) 243-7889 (TTY).

More Information

For Your Patients

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