H1N1 Influenza Virus Vaccine and its Side Effects

H1N1 influenza virus vaccine

What is H1N1 Influenza Virus Vaccine?

H1N1 influenza virus vaccine is used to prevent infection caused by the pandemic 2009 H1N1 influenza virus. H1N1 influenza is sometimes called “swine flu” because it originated in pigs. You cannot become infected with H1N1 influenza from eating pork products.

The injectable H1N1 influenza virus vaccine is a “killed virus” vaccine. H1N1 influenza virus vaccine is also available in a nasal spray form, which is a “live virus” vaccine.

Differences Between the H1N1 and Regular Flu Vaccine
The difference between regular flu vaccines and H1N1 vaccines is the virus that is used in the manufacturing process. Regular flu vaccine does not contain components of the 2009 H1N1 virus. Regular flu vaccines do not protect against H1N1, and H1N1 vaccines will not protect against the regular flu.

H1N1 Vaccine Immunization Schedule

  • Minimum age to administer this vaccine is 6 months.
  • For kids of age 6 months to 9 years: 2 doses with 4 weeks apart
  • For age above 9 years: Single dose
  • Annual re-vaccination with single dose


It will take about a week to 10 days for the shots to provide protection. H1N1 vaccines should be as safe and as effective as the regular seasonal flu vaccines.

Side Effects

Side effects of intra-nasal vaccine can include a runny nose, headache, wheezing, vomiting, muscle aches, fever, headache, sore throat, and cough.

Side effects of injection are as follows:
Serious side effects: Call your doctor immediately if you have
  • weakness, numbness or tingly feeling in your feet and spreading upward;
  • problems with vision, speech, swallowing, or bladder and bowel functions;
  • severe lower back pain;
  • slow heart rate, trouble breathing, feeling like you might pass out;
  • high fever; or
  • unusual bruising or bleeding.
Less serious side effects can last a day or two after you receive this vaccine and may include:
  • runny or stuffy nose;
  • low fever;
  • sore throat;
  • loss of appetite;
  • headache, tired feeling; or
  • muscle pain.
This is not a complete list of side effects and others may occur.