PIC QUESTION OF THE WEEK: 9/21/09 Q: Please provide some basic information on the 2009 H1N1 monovalent vaccine. A: On September 16, 2009, both an inactivated intramuscular vaccine and a live intranasal solution were licensed to protect against novel influenza A (H1N1) virus infection. The inactivated vaccine is expected to be available in early to mid-October and will be manufactured by four companies - CSL Limited, MedImmune LLC, Novartis Vaccines and Diagnostics Limited, and Sanofi Pasteur Inc. The nasal product may not be available as quickly. CDC’s Advisory Committee on Immunization Practices (ACIP) has recently provided preliminary guidelines on use of the vaccine. Patient categories considered at highest risk for acquiring and transmitting this infectious virus include: Pregnant women (regardless of trimester) Persons who live with or provide care for infants aged <6 months (e.g., parents, siblings, and daycare providers) Health-care and emergency medical services personnel Persons aged 6 months – 24 years Persons aged 25 – 64 years who have medical conditions that put them at higher risk for influenza-related complications (see list of medical conditions in the CDC link attached below) In the event vaccine supply is insufficient, subsets of some of these target categories will receive priority.
The following is a brief summary of other important aspects of the 2009 H1N1 monovalent vaccine: Immunization with the standard seasonal influenza vaccine offers little to no protection against the novel H1N1 virus Two doses of vaccine (separated by 21 days) may be required for children and young adults Seasonal and H1N1 2009 vaccines can be administered at the same time, but in different anatomical sites; simultaneous administration of the live formulations of each vaccine is not recommended Candidates for seasonal influenza vaccine should receive their dose as quickly as possible and not wait until the new H1N1 vaccine is available Thus far, adverse reactions to the vaccine have been minimal The vaccine will be available in formulations with and without the preservative thimerosal Antiviral treatment with oseltamivir (Tamiflu®) or zanamivir (Relenza®) follows the same guidelines as seasonal influenza and should be reserved for patients hospitalized due to influenza or at high risk for influenza-related complications.
The reader is referred to the attached CDC links for additional information on both the influenza A (H1N1) and seasonal influenza vaccines as well as the administration of antiviral medication.
References: Centers for Disease Control and Prevention. Use of influenza A (H1N1) 2009 monovalent vaccine. http://www.cdc.gov/mmwr/PDF/rr/rr5810.pdf. Accessed September 12, 2009. Centers for Disease Control and Prevention. Prevention and control of seasonal influenza with vaccines. http://www.cdc.gov/mmwr/PDF/rr/rr5808.pdf. Accessed September 12, 2009. Centers for Disease Control and Prevention. Updated interim recommendations for the use of antiviral medications in the treatment and prevention of influenza for the 2009-2010 season. http://www.cdc.gov/h1n1flu/recommendations.htm. Accessed September 15, 2009. Photo by: mamaluna1: used under Creative Commons License; http://www.flickr.com/photos/blumoonmama/3753094455/ (Accessed September 16, 2009)
Ashley M. Varhol and Ryan J. Genova, Pharm.D. Candidates The PIC Question of the Week is a publication of the Pharmaceutical Information Center, Mylan School of Pharmacy, Duquesne University, Pittsburgh, PA 15282 (412.396.4600).