Live attenuated influenza vaccine

Live attenuated influenza vaccine (LAIV) is a type of influenza vaccine in the form of a nasal spray that is recommended for the prevention of influenza. In June 2016 the CDC stopped recommending the use of LAIV as its effectiveness has appeared to have decreased between 2013 and 2016, but this recommendation was reversed in February 2018 for the 2018-2019 influenza season. Live attenuated influenza vaccine (LAIV) is a type of influenza vaccine in the form of a nasal spray that is recommended for the prevention of influenza. In June 2016 the CDC stopped recommending the use of LAIV as its effectiveness has appeared to have decreased between 2013 and 2016, but this recommendation was reversed in February 2018 for the 2018-2019 influenza season. It is an attenuated vaccine, unlike most influenza vaccines, which are inactivated vaccines. LAIV is administered intranasally, while inactivated vaccines are administered by intramuscular injection. LAIV is sold under the trade name FluMist in the United States and Canada, and Fluenz in Europe. FluMist is manufactured by MedImmune and was first introduced in 2003. In 2016 the CDC recommended that LAIV not be used for the 2016-2017 flu season and instead another type of influenza vaccine be used. This is due to the poor effectiveness of this type of vaccine between 2013 and 2016 with it being non effective during the 2015-2016 season. A 2012 review found that LAIV prevents influenza in about one out of six children under six it is given to. It was believed to prevent about 50% more cases of flu than the flu shot in younger children. In those less than 2 years old evidence the evidence was however unclear. Why there appears to be a decrease in effectiveness is unknown. However, in February 2018, the CDC Advisory Committee on Immunization Practices (ACIP) reinstated the use of LAIV for the 2018-2019 flu season. The inactivated and recombinant influenza vaccines are no longer preferred by ACIP over LAIV.