Photo Credit PHIL
# 5700
Just over 5 months ago - after consultations with public health officials, researchers, and pharmaceutical companies - the World Health Organization released their recommendation for the antigenic composition of this fall’s trivalent flu vaccine.
The decision was to stay with the same mixture as had been used in the 2010-2011 vaccine in the Northern Hemisphere, and as had been selected for 2011 south of the Equator.
• A/California/7/09 (H1N1)-like virus (pandemic (H1N1) 2009 influenza virus)
• A/Perth /16/2009 (H3N2)-like virus
• B/Brisbane/60/2008-like virus
The WHO also posted a full report with their rationale for each strain selection which you can access at:
The short version is: while minor variations have been observed in both the 2009 H1N1 and the seasonal H3N2 viruses over the past year, HI (Hemagglutination inhibition) testing of isolates suggest that the vast majority remain antigenically indistinguishable from the recommended strains.
Given the rapid evolution of influenza strains, and the six month lead time to produce each season’s vaccine, there is always the possibility that one of the strains in circulation may `drift’ antigenically away from the vaccine before the season ends.
Thus far, while some `low reactor’ strains have been detected, the majority of viruses tested appear to be a good antigenic match to the vaccine.
As they do every summer, the FDA has officially announced their approval of formulation, and the manufacturers, of this fall’s flu vaccines.
FDA NEWS RELEASE
For Immediate Release: July 18, 2011
FDA approves vaccines for the 2011-2012 influenza season
The U.S. Food and Drug Administration announced today that it has approved the influenza vaccine formulation for the 2011-2012 vaccine that will be used by the six manufacturers licensed to produce and distribute influenza vaccine for the United States.
Vaccination remains the cornerstone of preventing influenza, a contagious respiratory disease caused by influenza virus strains. The vaccine formulation protects against the three virus strains that surveillance indicates will be most common during the upcoming season and includes the same virus strains used for the 2010-2011 influenza season.
Between 5 percent and 20 percent of the U.S. population develops influenza each year, leading to more than 200,000 hospitalizations from related complications, according to the U.S. Centers for Disease Control and Prevention (CDC). Influenza-related deaths vary yearly, ranging from a low of about 3,000 to a high of 49,000 people.
“Vaccines to prevent seasonal influenza have a long and successful track record of safety and effectiveness in the United States,” said Karen Midthun, M.D., director of FDA’s Center for Biologics Evaluation and Research. “It is important to get vaccinated every year, even if the strains in the vaccine do not change, because the protection received the previous year will diminish over time and may be too low to provide protection into the next year.”
In addition to the important role that health care providers play in recommending influenza vaccination for their patients, influenza vaccination of health care personnel is also important to protect themselves, their patients, their family, and the community from influenza. The FDA urges health care organizations to encourage their members to follow CDC’s Advisory Committee on Immunization Practices (ACIP) recommendations to get vaccinated.
The brand names and manufacturers of the vaccines for the upcoming season are: Afluria, CSL Limited; Fluarix, GlaxoSmithKline Biologicals; FluLaval, ID Biomedical Corporation; FluMist, MedImmune Vaccines Inc.; Fluvirin, Novartis Vaccines and Diagnostics Limited; and Fluzone, Fluzone High-Dose and Fluzone Intradermal, Sanofi Pasteur Inc. Fluzone Intradermal, approved on May 9, 2011, will be available for those ages 18 years through 64 years. This vaccine is delivered into the skin, rather than the muscle, using a very small needle.
As far as who should get the seasonal flu vaccination every year, the CDC recommends:
Who should get vaccinated?
Everyone 6 months and older should get a flu vaccine each year. This recommendation has been in place since February 24, 2010 when CDC’s Advisory Committee on Immunization Practices (ACIP) voted for “universal” flu vaccination in the U.S. to expand protection against the flu to more people. While everyone should get a flu vaccine each flu season, it's especially important that certain people get vaccinated either because they are at high risk of having serious flu-related complications or because they live with or care for people at high risk for developing flu-related complications.
- Pregnant women
- Children younger than 5, but especially children younger than 2 years old
- People 50 years of age and older
- People of any age with certain chronic medical conditions
- People who live in nursing homes and other long-term care facilities
- People who live with or care for those at high risk for complications from flu, including:
- Health care workers
- Household contacts of persons at high risk for complications from the flu
- Household contacts and out of home caregivers of children less than 6 months of age (these children are too young to be vaccinated)
While no vaccine can be claimed to be 100% safe or 100% effective, seasonal influenza vaccines have an excellent safety profile - and most years (depending on the recipient) – provide pretty good protection as well.
Concerns over developing Guillain Barre Syndrome (GBS) as a result of a flu shot have been shown to be overstated (see BMJ: No Substantial Link Between Flu Vaccines And Guillain-Barre Syndrome), and in Lancet: The Influenza - Guillain Barré Syndrome Connection we looked at a study that found you have a far better shot of developing GBS from the flu virus itself.
I’ll be getting my flu shot again this year. I hope you will too.
