Millions of doses of seasonal flu vaccine have been distributed every year for many years and have a long and well-established safety record. All flu vaccines licensed in the U.S. – both seasonal and 2009 H1N1 – are produced in eggs and they do not contain adjuvants, which are additives that help generate a stronger immune response to the vaccine.
Each manufacturer of the 2009 H1N1 flu vaccine is using the same, well-established licensed manufacturing and testing processes that are used to make seasonal flu vaccines.
As with all vaccines, the CDC and the Food and Drug Administration (FDA) are closely monitoring any side effects associated with seasonal and 2009 H1N1 flu vaccines. Vaccine safety is always monitored as part of any vaccination program.
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Side effects
Immunizations, like any medication, can cause adverse reactions. Serious adverse reactions are rare. Side effects may be by chance or caused by vaccination. The most common side effects are mild and may include:
Flu shot
Soreness, redness, tenderness or swelling where the shot was given; low grade fever; and aches.
If these problems occur, they begin soon after the shot was administered, are usually mild, and usually last 1 to 2 days. Almost all people who receive the flu vaccine have no serious problems from it. However, on rare occasions, flu vaccination can cause serious problems, such as severe allergic reactions.
Nasal spray
In children: Runny nose; wheezing; headache; vomiting; muscle aches and fever.
In adults: Runny nose; headache; sore throat; and cough.
Seasonal flu vaccines are safe when they are administered properly. However, vaccines, like any medication, carry some risks. The CDC anticipates that the safety of the 2009 H1N1 vaccines will be similar to seasonal flu vaccines.
Click below for additional vaccine resources:
Thimerosal-Containing Influenza Vaccine
Influenza Vaccine Production, Supply & Distribution in the U.S.