What You Need to Know About the 2012-13 Flu Season: This Little Piggy

Within the next few weeks we can expect our first allotment of influenza vaccine to arrive in our offices (if it hasn’t arrived already). Yes, flu vaccination season is upon us sumo wrestling suits.

It is no time to be complacent after an unusually and extremely quiet 2012 flu season. In fact, the CDC is monitoring several recent variant swine strains of Influenza variant known as H3N2v. As of this August 2012, there have been about 154 cases of this variant identified (see CDC Table below).

Table. Case Count: Detected U.S. Human Infections with H3N2v by State since August 2011

States Reporting H3N2v Cases Cases in
2011
Cases in
2012
Hawaii 1
Indiana 2 120
Illinois 1
Iowa 3
Maine 2
Ohio 31
Pennsylvania 3
Utah 1*
West Virginia 2
Total 12 154

The 2012-2013 is a trivalent (containing three strains) vaccine. The strains contained within the vaccine were determined this past February 2012 by the World Health Organization and include:

  • an A/California/7/2009 (H1N1)pdm09-like virus;
  • an A/Victoria/361/2011 (H3N2)-like virus;
  • a B/Wisconsin/1/2010-like virus (from the B/Yamagata lineage of viruses).

According to the CDC, “…while the H1N1 virus used to make the 2012-2013 flu vaccine is the same virus that was included in the 2011-2012 vaccine, the recommended influenza H3N2 and B vaccine viruses are different from those in the 2011-2012 influenza vaccine for the Northern Hemisphere.” 

A constant area of confusion within the healthcare community is when should people receive the vaccine. The CDC addressed this in their last FAQ:

CDC recommends that influenza vaccination begin as soon as vaccine becomes available in the community and continue throughout the flu season. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against influenza, and influenza seasons can begin as early as October. Therefore, CDC recommends that vaccination begin as soon as vaccine becomes available to ensure that as many people as possible are protected before flu season begins.

The CDC has also offered guidance to those planning fairs with live animals and has wonderful free health care provider resources available.

Interestingly, this year the FDA approved the first quadrivalent flu vaccine which will include 2 strains of Influenza A and 2 strains of Influenza B. However, this won’t be available until the next flu season in 2013-2014. The vaccine will be in the form of the FluMist nasal vaccine, which will still be available this year as the trivalent vaccine with the above identified strains.

Both the CDC and WHO have robust reporting and surveillance data dedicated to influenza and should be regular web destinations for clinicians this flu season. Also check out the CDC’s Influenza Twitter feed @CDCFlu for pertinent updates. Finally, a cool tool is Google’s Flu Trends which has been shown to correlate with influenza activity based on people’s search inquiries based upon their location.

Of course, every influenza season is unpredictable. Prevention and preparation at all levels of public health are paramount to minimize the deadly complications from this respiratory virus. There should be adequate supplies of flu vaccine to go around this year, unlike the shortage of 2004. Clinicians and public health providers must be prepared for worst while stressing primary prevention strategies including vaccination.