Flu viruses are always changing. Each year, experts study thousands of flu virus samples from around the world to figure out which viruses are making people sick and how these viruses are changing. With this information, they forecast which three viruses are most likely to make the most people sick during the next flu season. These strains are then used to make the flu vaccine for the next flu season.
This year’s three flu strains included in the vaccine remain the same as last year’s vaccine:
* A/California/7/2009 (H1N1)-like virus
* A/Perth/16/2009 (H3N2)-like virus
* B/Brisbane/60/2008-like virus)
As noted above, this year's seasonal flu vaccine will again include the Novel 2009 H1N1 flu strand (A.K.A. A/California/7/2009 (H1N1)-like virus) which was used during the global pandemic and which was also included in last year's flu vaccine. This means your child will only need to get vaccinated with one type of flu immunization this year.
However, if your child is under 9 years of age AND did not receive the seasonal flu vaccine last year (the 2010-2011 flu vaccine), they will need to get 2 immunizations this year. This rule applies to both the nasal flumist and the injectable vaccine.
Flu shots given prior to the 2010-2011 flu vaccine (including the single strand Novel 2009 H1N1 vaccine) do not factor into this year's decision making tree. Please note that this is a different policy from previous years.
Here is a decision tree to help you know how many flu vaccines your child needs this year (you must answer both questions in the order shown):
Is your child 9 years or older?
Yes: Only one immunization is needed this year.
No: Go to the next question -->
Did your child receive at least one 2010-2011 seasonal flu vaccine?
Yes: Only one immunization is needed this year.
No: Two immunizations are needed this year.
If your child needs 2 flu vaccines this year, they should be spaced apart by a minimum of 4 weeks. There is no deadline by which the 2nd flu vaccine needs to be completed, but once the minimum 4 weeks has passed, the sooner the better.
Yearly flu vaccination should begin in September or as soon as the vaccine is available and continue throughout the influenza season, as late as March or beyond. The timing and duration of influenza seasons vary.
While influenza outbreaks can happen as early as October, most of the time influenza activity peaks in February or later. About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body.
In general, it is best to get your flu shot a.s.a.p. because you never know when the flu season will start!
For more information on the flu vaccine from the CDC click on this link.
