Each year, the U.S. Centers for Disease Control and Prevention (CDC) issues guidelines outlining the type of influenza vaccine recommended for specific groups of individuals sorted by age, medical status and other factors. In 2009, the CDC carried out campaigns to encourage both seasonal and H1N1 influenza vaccinations, so many people were immunized twice. For the 2010-2011 flu season, the CDC has endorsed one combination influenza vaccine for most Americans, according to Flu.gov.
Features
All influenza vaccines approved for the 2010-2011 flu season contain the same three viruses: the H1N1 virus that caused the 2009-2010 flu epidemic, a strain of influenza B that was common during the 2009-2010 flu season and an H3N2 virus that infection control experts expect to see during the 2010-2011 flu season.
Types
Influenza vaccines for the 2010-2011 flu season can be classified as either inactivated vaccines made with killed viruses or live, attenuated vaccines containing weakened live flu viruses. Traditional flu shots contain inactivated viruses, and are available in both a regular dose and a new high-dose product called Fluzone. Live influenza vaccine is delivered in an intranasal spray.
Which Vaccine?
Everyone 6 months of age or older should be immunized against influenza as soon as the vaccine is available for the 2010-2011 flu season. Most people are good candidates for a flu shot containing the inactivated virus, according to Flu.gov. The live intranasal vaccine is contraindicated in children under the age of 2 years, pregnant women, individuals with chronic diseases such as asthma and arthritis and anyone over the age of 49 years. Fluzone, which contains four times the amount of inactive virus as a traditional flu shot, is a good option for people over the age of 65 who typically have weaker immune systems than younger adults.
Misconceptions
Some people believe they're already protected against H1N1 influenza because they were vaccinated in 2009 or they were diagnosed with an H1N1 infection. The CDC says these individuals should still be vaccinated with a 2010-2011 influenza vaccine to ensure good protection against H1N1 and new strains of seasonal flu.
Tip
Flu.gov publishes a user-friendly table that outlines the type of influenza vaccine recommended for people of different ages and those with chronic medical conditions.
Warning
All forms of influenza vaccine are grown in eggs, so there is no safe form for people with severe egg allergies, according to the CDC.
