A US postmarketing evaluation of the frequency and safety of live attenuated influenza vaccine use in nonrecommended children younger than 5 years: 2009-2010 season

► LAIV is not recommended for children <24 months or those 24 through 59 months with asthma, recurrent wheezing, or immunocompromise. ► LAIV use in nonrecommended children was low compared with recommended populations. ► Among nonrecommended cohorts studied, use was greatest in those with recurrent wheezing. ► No excess in hospitalizations or ED visits within 42 days of vaccination was seen in nonrecommended populations. ► Few nonrecommended children were vaccinated with LAIV, precluding quantification of rare events.