Influenza virus vaccine, H1N1 is used to prevent infection caused by the influenza A (H1N1) 2009 virus. The vaccine works by causing your body to produce its own protection (antibodies) against the disease. It is also known as a "flu shot".

The pandemic influenza strain, or swine flu, that spread globally in 2009 was referred to as H1N1 and the new bird flu currently spreading in China is A H7N9. Most of us can probably understand.

The pandemic influenza strain, or swine flu, that spread globally in 2009 was referred to as H1N1 and the new bird flu currently spreading in China is A H7N9. Most of us can probably.

What are the signs and symptoms of H1N1 influenza? Your child's risk for severe symptoms is higher if he or she is younger than 5 years. A heart or lung disease or weak immune system also increases his or her risk. Your child may have any of the following: Fever and chills Headaches, body aches, earaches, and muscle or joint pain