FAQs About the Seasonal Flu Vaccine
- What is flu vaccine?
- Who should get flu vaccine and when?
- Who should not get the flu vaccine? Who should proceed with caution?
- What are the side effects of the flu vaccine?
What is flu vaccine?
The standard flu shot vaccine (or, the "flu shot") is made from flu viruses that have been grown on fertilized chicken eggs. The viruses are killed during manufacturing, a process known as “inactivation.” These inactivated viruses are a source of proteins or antigens that trigger a protective antibody response when the vaccine is injected into the arm or thigh muscle. Antibodies against flu viruses begin to appear one to two weeks after getting the flu shot and last for months, and sometimes even up to one year.
The standard flu shot is the main flu vaccine that will be offered at PAMF for the 2016 to 2017 season.
Two other flu vaccines will also be available to certain patients:
1) Fluzone High-Dose: Fluzone High-Dose vaccine, a flu shot with four times the antigen dose per strain of the standard flu vaccine, is approved only for people 65 years of age or older.
2) Flublok: Flublok is a recombinant flu vaccine manufactured without the use of eggs. It is indicated for people 18 years or older who are highly allergic to eggs. It is available only in our Allergy Departments.
Important Note: The Centers for Disease Control and Prevention (CDC) does not recommend the intra-nasal flu vaccine FluMist for this season, therefore we will not be offering this vaccine at PAMF.
PAMF has transitioned from trivalent to quadrivalent flu vaccines (containing two A strains and two B strains) with the exception of Fluzone High-Dose and Flublok which are still trivalent (two A strains and one B strain). The second B strain was added to quadrivalent vaccines by manufacturers because predicting which flu B strain would circulate in any given season proved difficult. While this is a modest change, scientists hope it will result in increased protection against the flu in coming years. The higher dose of antigens in Fluzone High-Dose vaccine produces higher antibody levels in patients 65 years or older which results in a modest boost in effectiveness compared to the standard-dose vaccine.
Because vaccine strains often change from one year to the next and immunity wanes, flu vaccine must be given every year.
All flu vaccines at PAMF will be Thimerosal-free and latex-free.
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Who should get flu vaccine and when?
The easy answer is that almost everyone 6 months of age and older should get the flu vaccine. They should get the vaccine in September or October, but they can be vaccinated throughout the flu season. Special efforts should be made to vaccinate the following people because they are either at risk for complications from the flu, or they might give the flu to someone who is at risk, incuding:
- Women who are or will be pregnant during the flu season and those up to two weeks post-partum â€“ the World Health Organization places a very high priority on vaccinating pregnant women
- Children younger than 5 years, especially children under age 2
- Children on chronic aspirin therapy
- People 50 years and older
- Persons who are morbidly obese
- Native American and Alaskan natives
- People of any age with certain chronic medical conditions
- People who live in nursing homes and other long-term care facilities
- People who live with or care for those at high risk for complications from flu, including:
- Health care workers
- Household contacts of persons at high risk for complications from the flu
- Household contacts and out of home caregivers of children less than 6 months of age (these children are too young to be vaccinated
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Who should not get the flu vaccine? Who should proceed with caution?
Flu vaccine is extremely safe for the vast majority of people, including breastfeeding and pregnant women (pregnant women should receive the flu shot, but should not get the FluMist nasal spray vaccine (FluMist will not be offered at PAMF this season learn more on the CDC website).
However, some groups should exercise caution:
- People with a history of severe allergic reaction to the flu vaccine or its components should not get the flu vaccine.
- People with a severe allergy to eggs should consult an allergist.(Flubok may be considered if the patient is 18 years of age or older.)
- People with milder allergic reactions to eggs (such as hives only) should speak with their vaccine or health care provider first. (Usually the standard flu shot can be administered, followed by at least 15 minutes of observation. As an alternative, Flublok vaccine, which is not egg-based, can be given by an allergist if the patient is 18 years of age or older).
- Anyone with moderate to severe acute illness should delay flu vaccination until resolution of the illness.
- Children under 6 months of age should not get the flu vaccine because it is ineffective in this age group (instead, their household contacts and caretakers should get vaccinated).
- People with a history of Guillain-Barre syndrome should consult their doctor before receiving the flu vaccine.
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What are the side effects of the flu vaccine?
The flu vaccine rarely causes serious adverse effects. The most common reaction to the flu shot is mild soreness at the site of injection which is well tolerated. Flu-like symptoms, such as fever and muscle aches, occasionally occur six to 12 hours after receiving the flu shot and last one to two days. However, these symptoms are very rare.
Guillain-Barre syndrome (GBS), an acute paralytic illness, was linked to the swine flu vaccine of 1976. Since 1976, studies have failed to show a similar association between flu vaccines and GBS. It is estimated that at most one excess case of GBS per million people vaccinated may be attributable to the flu vaccine. The extremely low incidence of GBS stands in contrast to the many hospitalizations and deaths prevented by the flu vaccine. Moreover, influenza itself is known to cause GBS and the flu vaccine may be protective. However, anyone who has had GBS within six weeks of flu vaccination should speak with their physician first before receiving flu vaccine.
For more information, visit the CDC web site and these pages on the PAMF.
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