Quadrivalent Influenza Vaccine
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- What is quadrivalent flu vaccine?
- Why was quadrivalent flu vaccine developed?
- Who can get quadrivalent flu vaccine?
- Who shouldn’t get quadrivalent flu vaccine?
- Are any of the available flu vaccines recommended over the others?
- How much of the flu vaccines for the United States during 2018-2019 will be quadrivalent?
- Are quadrivalent flu vaccines safe?
- What should people do if they can’t find quadrivalent vaccine?
- Will quadrivalent flu vaccine be more expensive than trivalent flu vaccines?
- Egg Allergy
The quadrivalent flu vaccine is designed to protect against four different flu viruses; two influenza A viruses and two influenza B viruses.
For years, flu vaccines were designed to protect against three different flu viruses (trivalent vaccines). Trivalent vaccines include an influenza A (H1N1) virus, an influenza A (H3N2) virus and one influenza B virus. Experts had to choose one B virus, even though there are two different lineages of B viruses that both circulate during most seasons. This meant the vaccine may not protect as well against the group of B viruses not included in the vaccine. Adding another B virus to the vaccine aims to give broader protection against circulating flu viruses.
Different vaccines are approved for different age groups. There is a quadrivalent flu shot that can be given to children as young as 6 months of age. Other quadrivalent flu shots are approved for people 3 years and older. More information on approved flu vaccines for the 2018-2019 flu season, and age indications for each vaccine are available in CDC’s Table: U.S. Influenza Vaccine Products for the 2018-19 Season.
The quadrivalent nasal spray vaccine is approved for use in non-pregnant individuals, 2 years through 49 years of age. People with some medical conditions should not receive the nasal spray flu vaccine.
Different flu vaccines are approved for use in different age groups. In addition, some vaccines are not recommended for certain groups. 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.
For the 2018-2019 flu season, the Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for everyone 6 months and older with any licensed age-appropriate flu 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.
Of the 163 to 168 million doses of influenza vaccine projected to be available for the 2018-2019 season, manufacturers estimate that 114 million to 124 million doses will be quadrivalent flu vaccine.
Yes. Flu vaccines that protect against four flu viruses are made in the same way as the flu vaccines that have been around for years that protect against three flu viruses. The difference is the added protection against another flu virus. Studies have shown that vaccines made to protect against four flu viruses have a safety profile similar to seasonal flu vaccines made to protect against three viruses, with similar—mostly mild—side effects. Hundreds of millions of people have safely gotten flu vaccines that protect against three flu viruses. Like all seasonal flu vaccines, vaccines that protect against four flu viruses are monitored for their safety and effectiveness.
Quadrivalent vaccine cannot cause influenza illness because the vaccine viruses used to make it are ‘inactivated’ (killed) or attenuated (weakened).
For information about flu vaccine side effects, see “Can the flu vaccine give me the flu?”
Don’t delay getting vaccinated if you cannot locate a quadrivalent vaccine. The important thing is to get vaccinated against influenza. Find flu vaccine near you using the vaccine finder at http://vaccine.healthmap.org/. Call ahead to ask about availability if you are interested in a specific type of vaccine.
Quadrivalent flu vaccines may cost more than trivalent vaccines. Ask your insurance provider or doctor to find out how much you may need to pay and how much of the cost is covered by insurance.
People with egg allergies can receive any licensed, recommended age-appropriate influenza 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.
- Page last reviewed: October 2, 2018
- Page last updated: October 2, 2018
- Content source:
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases (NCIRD)
- Page maintained by: Office of the Associate Director for Communication, Digital Media Branch, Division of Public Affairs