The Centers for Disease Control and Prevention (CDC) announced that the flu shot available to the public this year is a much better match for the flu virus that is expected to circulate during this year's flu season. Last season’s vaccine did not protect against a particular strain of H3N2 flu virus – known as the "Switzerland variant” – causing the vaccine's effectiveness rate against the H3N2 strain to be only about 13 percent.

In an effort to get it right in 2015, scientists scrutinized 199 flu specimens collected in the United States and elsewhere between May 24 and Sept. 5. The majority of those specimens were H3N2 viruses and all were built in a way that should make them vulnerable to this year’s vaccines, according to the CDC’s latest Morbidity and Mortality Weekly Report (MMWR).

In the United States, annual influenza vaccination is recommended for all persons aged 6 months and older who do not have contraindications. Manufacturers of the vaccine expect this season to see the largest supply of influenza vaccine distributed in the United States during one season with the exception of the 2009 pandemic.

To see the CDC MMWR on flu vaccine for 2015, click here.