By Mike McEvoy
The World Health Organization (WHO) officially declared the H1N1 pandemic over on July 10, 2010, transitioning global alert and response activities to “post-pandemic” stage. This does not mean the H1N1 (2009) influenza virus is no longer active, in fact, outbreaks are expected to continue as the virus seems to have transitioned into the dominant flu virus as we enter the 2010 influenza season. Based on its Advisory Committee on Immunization Practices (ACIP), which develops recommendations for seasonal influenza vaccine components and administration, the Centers for Disease Control have decided that the 2010-2011 seasonal flu vaccine will contain A/California/7/2009 (H1N1)-like, A/Perth/16/2009 (H3N2)-like, and B/Brisbane/60/2008-like antigens. The H1N1-like antigen is made from a pandemic 2009 flu virus and is the same antigen used in the H1N1 pandemic vaccines. The H3N2-like antigen is different from the H3N2-like antigen included in the 2009-2010 vaccine, based on worldwide surveillance of current viruses in circulation. The influenza B vaccine strain remains unchanged from the 20092010 flu vaccine. Seasonal flu vaccines normally contain three antigens (2 type A and one type B). The Centers for Disease Control continues to update guidance on who should be vaccinated, based on vaccine safety and observations during the H1N1 pandemic in which children, younger adults and pregnant women seemed particularly susceptible. As of August 2010, seasonal vaccines were available; FireEMS departments should begin making plans to offer vaccination to their members as early as possible. The CDC has also begun updates to their guidance documents on prevention of influenza spread in health care settings, particularly pertaining to use of masks by health care providers. Current (and all future) revisions call for use of plain surgical or procedure masks by health care personnel caring for potentially infectious influenza patients. This is in stark contrast to directives issued in the fall of 2009 which called for N-95 masks.