Each year brings a new cold and flu season. As a pharmacist it's good to know what lies ahead.
Flu season is unpredictable and changes from season to season. In the U.S. the flu normally peaks in January or February, but you can see flu activity begin as early as October and continue until May.
According to the Centers for Disease Control
, manufacturers have projected that they will produce between 135 million and 139 million doses of influenza vaccine for use in the U.S. during the 2013-2014 influenza season. An estimated 30 million to 32 million of these does will be quadrivalent flu vaccine. The rest will be trivalent flu vaccine.
What flu viruses does this season's vaccine protect against?
Flu vaccines are designed to protect against the influenza viruses that experts predict will be the most common during the upcoming flu season. There are three kids of influenza viruses that commonly circulate among people today: Influenza A (H1N1) viruses, influenza A (H3N2) viruses, and influenza B viruses. Each year, these viruses are used to produce seasonal influenza vaccine.
The 2013-2014 trivalent influenza vaccine is made from the following three viruses:
- an A/California/7/2009 (H1N1)pdm09-like virus;
- an A(H3N2) virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011;
- a B/Massachusetts/2/2012-like virus.
It is recommended that the quadrivalent vaccine containing two influenza B viruses include the above three viruses and a B/Brisbane/60/2008-like virus.
How effective is the flu vaccine?
Inactivated influenza vaccine effectiveness (VE) can vary from year to year and among different age and risk groups.
How long does a flu vaccine protect me from getting the flu?
Multiple studies conducted over different seasons and across vaccine types and influenza virus subtypes have shown that the body's immunity to influenza viruses declines over time. The decline in antibodies is influenced by several factors, including the antigen used in the vaccine, age of the person being vaccinated, and the person's general health.
The CDC recommends a yearly flu vaccine for everyone 6 months of age and older. Flu vaccines are offered in many locations, including most local pharmacies
or urgent care clinics.
Read more at: CDC