Hello, I am Dr. Tim Uyeki from CDC's Influenza Division. I am pleased to speak with you today as part of the CDC Expert Commentary Series on Medscape.
The 2012-2013 influenza vaccination recommendations share many similarities with recommendations from previous influenza seasons, but there are a few changes that I would like to highlight. Briefly, I am going to talk about influenza vaccine composition, vaccine options, the child dosing recommendation, and vaccination for those with egg allergies. Before we get started, I would like to point out that the annual "universal" influenza vaccination recommendation for everyone 6 months of age and older continues this season.
All influenza vaccines available in the United States this season are trivalent, containing 3 antigens, including 2 influenza A strains and 1 influenza B strain. The 2012-2013 influenza vaccine composition is different from influenza vaccines for the last 2 seasons, with changes to 2 of the 3 strains. Although the H1N1 strain remains the same, the H3N2 and B components of the vaccine are different from strains used in the northern hemisphere influenza vaccines in recent seasons. These changes were made on the basis of global surveillance data on circulating influenza virus strains.
Influenza Vaccine Options
The vaccination options are similar to last year. There are 3 trivalent inactivated vaccines (TIV), as well as a live attenuated influenza virus vaccine (LAIV), the nasal spray vaccine. Thimerosal-free vaccines will be available. There is no preferential recommendation for any of the formulations of TIV or LAIV for healthy, nonpregnant individuals ages 2-49 years, but clinicians should note the recommended age groups and possible contraindications for each formulation. The 2012-2013 "Influenza Vaccine Recommendations" provided by the Advisory Committee on Immunization Practices (ACIP) should also be consulted.
The trivalent inactivated vaccine is approved for use in patients 6 months and older, including those with high-risk medical conditions and pregnant women. Different formulations of this vaccine are available from various manufacturers, and age indications vary by manufacturer, so refer to the package inserts to ensure that the vaccine is suitable for your patient's age.
The high-dose TIV was introduced in 2010 for people 65 years and older. It contains 4 times the amount of antigen as other influenza vaccines and is administered intramuscularly.
The intradermal influenza vaccine was approved in 2011 for use in people aged 18-64 years. The intradermal vaccine contains less antigen than either of the other TIV formulations but induces a similar immune response. It is administered with a prefilled syringe into the dermal layer of the skin with a much smaller needle.
Finally, LAIV for intranasal spray administration, is available for healthy, nonpregnant people 2-49 years.
In February 2012, the US Food and Drug Administration approved a new quadrivalent LAIV, called Flu Mist Quadrivalent (MedImmune, LLC; Gaithersburg, Maryland). However, this vaccine is not anticipated to be available until the 2013-2014 influenza season. Inactivated quadrivalent influenza vaccines are currently in development. ACIP will address specifics pertaining to any new influenza vaccines once they are approved and become commercially available.
Child Dosing Recommendations
Now I will talk about the child dosing recommendation for this season. Similar to influenza vaccination recommendations for children in previous years, young children aged 6 months to 8 years who have never been vaccinated against influenza require 2 doses of influenza vaccine, administered at least 4 weeks apart, for full protection. For the last several seasons, some children who received 2 doses previously have needed another 2 doses to be adequately protected against 2009 H1N1 virus, the same virus that caused the most recent influenza pandemic, which is expected to circulate again this season. The 2009 H1N1 antigen was present in the seasonal influenza vaccines for the 2 previous seasons (2010-2011 and 2011-2012) and was also present in the 2009 H1N1 monovalent vaccine. For this season, ACIP recommends 2 approaches for determining the number of doses needed for children in this age group, both of which are acceptable.
The first approach takes into consideration only doses of seasonal influenza vaccine received since July 1, 2010. This approach has the advantage of simplicity, particularly if ascertaining vaccination history before the 2010-2011 season is difficult. Using this approach, children aged 6 months to 8 years need only 1 dose of vaccine in 2012-2013 if they received a total of 2 or more doses of seasonal vaccine since July 1, 2010. Children who have not received 2 or more doses of seasonal vaccine since July 1, 2010, require 2 doses in 2012-2013.
If adequate vaccination history from before the 2010-2011 season is available, the second approach may be used. By this approach, if a child aged 6 months to 8 years is known to have received at least 2 seasonal influenza vaccines during any previous season, and at least 1 dose of a 2009(H1N1)-containing vaccine (either the 2010-2011 or 2011-2012 seasonal vaccine or the monovalent 2009 [H1N1] vaccine), then the child needs only 1 dose for 2012-2013. Using this approach, children aged 6 months to 8 years need only 1 dose of vaccine in 2012-2013 if they have received any of the following:
2 or more doses of seasonal influenza vaccine since July 1, 2010; or
2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009 (H1N1) vaccine; or
1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010.
If vaccination status is unknown for children in this age group, administer 2 doses of seasonal influenza vaccine. An algorithm should be used guide you when considering influenza vaccination for children 6 months to 8 years of age (Figure).
Figure. Child dosing algorithm showing influenza vaccine dosing for children aged children 6 months to 8 years in the United States, during the 2012-2013 influenza season. Children are recommended to receive 2 doses this season, even if 2 doses of seasonal influenza vaccine were received before the 2010-2011 season.
Egg Allergy and Other Considerations
Beginning with the 2011-2012 season, the ACIP recommended that people with mild allergies to egg -- specifically, those who experience only hives in response to egg exposure -- should receive influenza vaccine. This recommendation continues for 2012-2013. People who have experienced only hives after consuming eggs should receive TIV intramuscularly as long as they are treated by a healthcare provider who is familiar with the potential manifestations of egg allergies and can be observed by a healthcare professional for at least 30 minutes after receiving each dose. LAIV should not be used in patients with allergy to eggs.
As a final note, CDC would like to stress the importance of the provider recommendation. Research supports the notion that vaccination recommendations from the patient's healthcare provider are more effective in increasing patient acceptance of vaccination than any other influencing factor.
CDC offers many free resources, including brochures, posters, and fact sheets, to help you educate your patients about influenza and influenza vaccines. Some of these materials can be ordered and shipped directly to your location, and others are available online for downloading to an office printer. We also encourage you to use our prepared social media tools, which can be added to your Website. Visit www.cdc.gov/flu, and select the "Free Resources" link to access these materials. Send an email to fluinbox@cdc.gov if you have questions or would like to receive flu-related updates directly from CDC.
Web Resources
CDC: Recommendations of the Advisory Committee on Immunization Practices
Dr. Tim Uyeki is Deputy Chief for Science in the Epidemiology and Prevention Branch of the Centers for Disease Control and Prevention's (CDC) Influenza Division. Since 1998 he has worked on the epidemiology, prevention, and control of interpandemic, zoonotic, and pandemic influenza in the United States and worldwide for CDC. Dr. Uyeki serves as a consultant to the World Health Organization (WHO) on clinical and epidemiologic issues related to seasonal, zoonotic, and pandemic influenza.
After completing his undergraduate work at Oberlin College, Dr. Uyeki earned master's degrees in public policy and public health (epidemiology) from the University of California, Berkeley, and a medical degree from Case Western Reserve University School of Medicine. Dr. Uyeki completed residencies in pediatrics at the University of California, San Francisco (UCSF), and in preventive medicine at UCSF-UC Berkeley. He then completed a 2-year Epidemic Intelligence Service applied epidemiology fellowship at CDC.
Board-certified in pediatrics, preventive medicine, and public health, Dr. Uyeki serves as an associate clinical professor in the Department of Pediatrics at the University of California, San Francisco. He is also an adjunct associate professor in the Hubert Department of Global Health at Emory University's Rollins School of Public Health.
