Listen to the CDC–Get a Flu Shot

The impending fall and cooler temperatures are already bringing news reports on the upcoming flu season and the importance of getting vaccinated.  Along with those reports, however, are opponents warning against the dangers of the vaccines, citing the ineffectiveness of recent flu vaccines, particularly with the 2012-2013 season. For some, the decision to get vaccinated is a no-brainer.  For others, it may not be that simple.


The CDC and HHS recommend a flu shot for everyone over the age of 6 months. It is particularly important for individuals to be vaccinated if they are or someone in their household is susceptible to complications from the flu; those at higher risk include children and infants, pregnant women, seniors, the disabled,people with chronic conditions such as asthma, arthritis, or diabetes and people traveling or living abroad or if they live with someone who is susceptible.

Vaccine Effectiveness

Just how effective a vaccine will be against influenza varies widely and is largely up to interpretation.  There is no way to know in advance how bad a flu season will be or how effective that year’s vaccine will be to prevent it. The components of the vaccine for any given year are determined based on the main flu strains that are projected to be the most prevalent. The 2013-2014 trivalent vaccine, for example, contains the following strains: (1) an A/California/7/2009 (H1N1)pdm09-like virus; (2) an A(H3N2) virus antigenically like the cell-propagated prototype virus A/Victoria/361/2001; and (3) a B/Massachusetts/2/2012-like virus. A quadrivalent vaccine also contains a B/Brisbane/60/2008-like virus. Last year’s vaccine contained two similar strains, A/California/7/2009 (H1N1)-like virus and an  A/Victoria/361/2011 (H3N2)-like virus, but differed with regard to the third,  which was a B/Wisconsin/1/2010-like virus.

Flu vaccines are generally between 60 to 70 percent effective in preventing influenza in all age groups, according to the CDC. However, figures reported by the media may have been adjusted to a certain age or risk group, and not interpreted correctly by the reports. That is why the vaccine effectiveness was as low as nine percent for the 2012-2013 flu season, as reported by the media.

In February 2013, the CDC reported that the overall effectiveness of the 2012-2013 vaccine was  56 percent. When the effectiveness was adjusted for individuals over the age of 65, it was estimated to be 27 percent. The nine percent effectiveness reported in the media was, in fact, the effectiveness of only one of the components of the 2012-2013 vaccine (flu A–H3N2) for the elderly.

Manufacturers and Brand Names

There are are 8 lots of vaccines, in a shot or nasal mist form, being distributed by manufacturers this year.  Those include: (1) AFLURIA (CSL Limited); (2) Fluarix (GlaxoSmithKline Biologicals); (3) Fluarix – Quadrivalent (GlaxoSmithKline Biologicals); (4) FluLaval (ID Biomedical Corp. of Quebec); (5) FluMist Quadrivalent (MedImmune, LLC); (6) Fluvirin (Novartis Vaccines and Diagnostics Limited); (7) Fluzone (Sanofi Pasteur, Inc.); and (8) Fluzone Quadrivalent (Sanofi Pasteur, Inc.). The CDC estimates that there are between 135 and 139 million doses of the flu vaccine that will be produced for this flu season, with nearly 80 percent of those being trivalent vaccines.

Coverage of Vaccine

Medicare covers one flu shot for Medicare beneficiaries each flu season, starting in the fall. .  If the provider accepts assignment from Medicare for giving the shot, there is no charge to the beneficiary. Coverage of flu vaccines may be provided by private health insurance, particularly under the Affordable Care Act  (P.L. 111-148) coverage of preventive services. If insurance does not cover the vaccine, it is often available at pharmacies at low cost.

A post discussing the 2012-2013 flu vaccine appeared in this blog in August 2012.