Recently, officials from the Centers for Disease Control (CDC) released guidance regarding influenza vaccination for the upcoming 2011-2012 influenza season. This included information about the anticipated strains of influenza virus during this year’s season, recommendations for special groups of individuals, and announced the release of a flu vaccine delivery method. Here are the highlights from that update:
- Predicted strains: Most seasons, the antigens that provide protection in flu vaccine are changed to keep up with the influenza viruses as they evolve. This year, however, the predicted strains of influenza virus likely to affect Americans are as they were for last year (A/California/7/2009 (H1N1)-like virus; A/Perth/16/2009 (H3N2)-like virus; and B/Brisbane/60/2008-like virus).
Accordingly, the vaccine is unchanged from last year. This does not mean, however, that people who received flu immunization last year are adequately protected this year. The levels of protective antibody against influenza viruses can decline over the course of a year, so even people who got a flu vaccine last year should be vaccinated again this year to make sure that they are optimally protected.
- Children: The CDC recommends that annual flu immunization should begin at 6 months of age. Children aged 6 months through 8 years need 2 doses of influenza vaccine, administered a minimum of 4 weeks apart, during their first season of vaccination to optimize immune response. Because the 2011-2012 vaccine strains are unchanged from the 2010-2011 vaccine strains, children in this age group who received at least one dose of the 2010-2011 seasonal vaccine will require only one dose of the 2011-2012 vaccine.
- Pregnant women: The CDC is making a special effort to see that pregnant women receive flu vaccine. Pregnant women and children younger than 6 months of age are at higher risk for severe illness from influenza. Vaccination during pregnancy has the double benefit of decreasing the risk for illness in the mother as well as the risk of influenza and its complications in infants during the first 6 months of life.
- Egg Allergy: Two types of vaccine are used for influenza immunization. The injectable form (“flu shot”) uses an inactivated vaccine that contains viruses that have been killed. A second type, given as a nasal spray, is made with live, butweakened flu viruses. Both vaccines are produced using eggs and can cause allergic reactions in someone with an egg allergy. For those individuals who have had only a mild reaction to eggs, such as hives, the CDC advises that they receive the flu shot rather than the intranasal form. A healthcare provider familiar with the manifestations of egg allergy should administer the injection and the recipient should be observed for at least 30 minutes afterward. People who have had a previous severe allergic reaction to eggs or from influenza vaccine should not receive flu vaccine. Severe reactions include swelling of the face or throat, respiratory distress, lightheadedness and recurrent vomiting. These individuals are at greater risk for severe reactions, including anaphylaxis, with re-exposure to egg proteins contained in the flu vaccine
- New preparation: In addition to the traditional flu shot and the intranasal preparation, there is a new type of flu shot that is delivered just beneath the skin (Fluzone Intradermal, Sanofi Pasteur). This intradermal flu vaccine uses an ultra-thin needle and may be preferable for people who don’t like shots. This type of vaccine has been approved for adults 18 through 64 years of age and is equally effective as the regular flu shot.
Last year, the CDC made the recommendation that everyone 6 months and older should receive the flu vaccine annually. The influenza vaccine will keep you from getting sick from the virus strains contained in the vaccine and it can make your illness milder if you get a related but different strain of the influenza virus. Since it takes about two weeks following vaccination for antibodies to develop in the body and provide protection against influenza virus infection, it’s a good idea to be vaccinated as soon as the vaccine becomes available, rather than waiting for flu season’s first outbreak.