Influenza in mammals, particularly humans, can be caused by different strains of viruses.  H3N2 is a virus type that can cause seasonal influenza.  In fact, H3N2 has been causing more cases of seasonal flu in each successive year.

Seasonal influenza is a major problem for people all over the world, especially in America, every single year. This is because different strains and mutations of the influenza virus like H1N1, H3N2, and H1N2 all require a slight variation of the flu vaccine.

For example, separate vaccine serums are developed in the North and South Hemispheres year to year.  However, the strain of H3N2 has been one of the most prevalent and commonly found strains in many regions.  In addition, certain drugs that are typically prescribed to treat the H3N2 strain of the seasonal flu have begun to be less effective.  This is because the H3N2 strain has increased resistance to these drugs from 1% resistance in 1994 to 91% in 2005.

Global health officials need to be able to determine the source of different strains of seasonal influenza in order to properly determine which strain will be the most prevalent the following year.  This is critical because the proper vaccines and treatment medications can be manufactured to prevent a large-scale breakout of seasonal influenza.

While around 36,000 Americans are killed each year due to the seasonal flu and complications following the illness, the disease usually affects young adults and children the most frequently.  This is especially true with pandemic strains of influenza.  However, the H3N2 strain of the virus traditionally affects the elderly, those over the age of 65, more often.  People in this age group are consequently more likely to be hospitalized and potentially die at a greater rate than their younger counterparts.

The H3N2 strain of the seasonal flu has affected the world, just not North America.  In 2003 and 2004, the Fujian Flu affected certain areas of Asia.  This particular case was caused by both H3N2 and another strain of bird flu called H5N1.  This was one of the most severe cases of season flu in this particular area of the People’s Republic of China in recent history.  This led to a vaccine with more of a focus on the H3N2 strain of influenza for the next year (2004 – 2005).

The H1N1 strain of influenza has gotten the majority of main stream media coverage in the United States, but the H3N2 virus is just as dangerous if the proper vaccinations and preparations cannot be made in advance of flu season.