How do flu vaccines work?

Flu vaccines (the flu shot and the nasal-spray flu vaccine) cause antibodies to develop in the body. These antibodies provide protection against infection with the viruses that are in the vaccine.

The seasonal flu vaccine protects against three influenza viruses that research indicates will be most common during the upcoming season. The 2011-2012 flu vaccine provides protection against the three main viruses that research indicates will cause the most illness this season. The 2011-2012 flu vaccine will protect against an influenza A (H1N1) virus, an influenza A (H3N2) virus and an influenza B virus.

About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body.

Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

Before the flu vaccine was first developed in the 1930s and widely used in the 1950s, influenza was a global killer. Doctors have been struggling with treating this disease since its first recorded outbreak in the 1500s. Many of us who currently get the flu experience its typical symptoms: cough, fever, sore throat, fatigue, soreness, and chills. However, it can quickly escalate, leading to bronchitis, pneumonia, heart failure, and death—especially in infants and the elderly.

One notable influenza epidemic unfolded late in 1918 and through much of 1919. Across the globe, the influenza virus killed 20-40 million people and affected up to 500 million people. It has been often cited as the “worst epidemic in recorded history.”

Doctors knew something innovative had to be done. Some discovered that transfusing blood from someone who had survived influenza into a sick person improved survival, which gave doctors an idea to develop a preliminary version of a vaccine. If we taught our bodies to fight influenza before it actually contracts influenza, survival would skyrocket.

The vaccine further developed with the advent of vaccine technology. It contains a dead, inactive version of the culprit virus, which compels your body to make antibodies against the real virus. Now, thanks to the vaccine, deaths from influenza have dramatically decreased. It’s amazing that a relatively inexpensive shot can save so many lives by preventing illness.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.