AAP: LAIV not effective against influenza A H1N1 viruses in children 2 through 8 years during the 2013-?14 influenza season

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NEWS AND FEATURES

Copyright ? 2014, The American Academy of Pediatrics

LAIV not effective against influenza A H1N1 viruses in children 2 through 8 years during the 2013-?14 influenza season

New observational data from the U.S. Flu Vaccine Effectiveness Network and two additional studies conducted during the 2013-?14 influenza season unexpectedly showed that the live attenuated influenza vaccine (LAIV) was not effective against the influenza A H1N1 pandemic strain (H1N1 pdm09) virus when compared with inactivated influenza vaccine (IIV) in children 2 through 8 years of age. Specifically, children 2 through 8 years immunized with LAIV were not protected against H1N1 pdm09.

The data were presented at the Oct. 29 meeting of the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC).

Estimates of vaccine effectiveness during the 2011-?12 and 2012-?13 influenza seasons suggested that LAIV effectiveness was similar, but not superior to IIV against influenza A H3N2 and influenza B viruses. These findings are contrary to earlier studies that had suggested superior efficacy of LAIV in children ages 2 years through 8 years.

Additional data are needed to understand the poor effectiveness of LAIV against influenza A H1N1 viruses during the 2013-?14 season and to determine possible implications for the 2015-?16 influenza season. The CDC and the Academy are exploring the issue of vaccine effectiveness, including working with the manufacturer of LAIV (MedImmune).


Interim AAP guidance for the 2014-?15 season

The CDC has not changed its recommendations for the preferential use of LAIV in healthy children 2 through 8 years of age for this season. The Academy, unlike the CDC, did not express a preference for LAIV for this influenza season (http://pediatrics.aappublications.org/content/134/5/e1503). In light of the recent effectiveness estimates, the Academy is providing additional interim guidance:

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http://aapnews.aappublications.org/content/early/2014/11/06/aapnews.20141106-1

 

[Emily]

Re: AAP: LAIV not effective against influenza A H1N1 viruses in children 2 through 8 years during the 2013-?14 influenza season

http://seattletimes.com/html/localnews/2025183237_flumistxml.html

Originally published December 6, 2014 at 3:20 PM | Page modified December 7, 2014 at 11:16 AM
Vaccine problems may signal rocky flu season



By JoNel Aleccia

Seattle Times health reporter

...

The problem with FluMist is different. Scientists still don?t know why the vaccine failed almost completely to protect against the H1N1 swine-flu strain last year, particularly in the youngest patients.

?This was very surprising,? said Mike Jackson, a scientific investigator at Group Health Research Institute in Seattle, one of five sites across the country that routinely conduct vaccine-effectiveness checks for the CDC. ?It?s really quite different from the way this specific vaccine performed in the last couple years.?

In fact, CDC officials were so confident about the nasal spray, which uses a live but weakened virus, that in June they recommended that it be the first choice for kids ages 2 to 8 for the 2014-2015 season...