- Category: Influenza
- Published on Tuesday, 30 August 2011 00:00
- Written by Liz Highleyman
The U.S. Centers for Disease Control and Prevention (CDC) recently recommended that everyone age 6 and older should be vaccinated against influenza, even though the 3 flu strains included in this year's vaccine -- including pandemic H1N1 "swine" flu -- are the same as last year's.
As described in the August 26, 2011, issue of Morbidity and Mortality Weekly Report, the CDC's Advisory Committee on Immunization Practices (ACIP) advised that all eligible individuals should receive this season's vaccine, which offers protection against the H1N1 and H3N2 strains of influenza A, as well as an influenza B strain. While these are the same strains in last year's vaccine, protection can wane over time, leading to the recommendation for re-vaccination.
"To permit time for production of protective antibody levels, vaccination should optimally occur before onset of influenza activity in the community, and providers should offer vaccination as soon as vaccine is available," the committee advised.
Groups especially targeted for vaccination include healthcare workers and pregnant women, who tend to experience more severe influenza symptoms.
A number of vaccines are expected to be available for the 2011-2012 season, all of which contain the same 3 influenza antigens. These include a newly approved intradermal formulation of the trivalent inactivated Fluzone vaccine for adults aged 18-64 years. A higher-dose Fluzone formulation is available for people age 65 and older. Healthy children and adults age 2-49 years, excluding pregnant women, may receive the intranasal FluMist live attenuated vaccine.
HIV positive people should receive an inactivated flu vaccine rather than a live attenuated formulation, but those with advanced immunodeficiency may have a poor response.
Children age 6 months to 8 years should receive 2 doses of influenza vaccine, administered a minimum of 4 weeks apart, during their first season of vaccination. But children can receive only 1 dose this year if they had at least 1 dose last year, the committee said.
The MMWR report discusses new recommendations regarding vaccination for people with egg allergies, since standard vaccines are prepared by growing influenza virus in eggs. Individuals who have developed hives after exposure to eggs can receive a trivalent inactivated vaccine (but not a live attenuated vaccine) and should be vaccinated by a healthcare provider familiar with egg allergies and observed for at least 30 minutes. People who have had more severe allergic reactions to eggs should be managed by clinicians with allergy expertise in a facility that can treat anaphylactic shock. A previous severe allergic reaction to a flu vaccine is a contraindication for further vaccinations.
L Grohskopf, T Uyeki, J Bresee, et al. Prevention and Control of Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2011. Morbidity and Mortality Weekly Report 60(33):1128-1132 (full text). August 26, 2011.