Assessing Fever Rates in Children Ages 24 to 59 Months After Live Attenuated Influenza Vaccine (LAIV) or Inactivated Influenza Vaccines (IIV) Using Text Messaging for U.S. Influenza Vaccines in 2012-2013 & 2013-2014

In this study, the investigators will prospectively assess fever rates in 24-59 month old patients during days 0-10 after administration of inactivated influenza vaccine (IIV) or live attenuated influenza vaccine (LAIV). Children in one of three study sites who receive these vaccines as part of their routine care can enroll in this study if their parent has the ability to receive and send text messages. Children enrolled in this study will be observed for an eleven day period starting on the day of vaccine administration via a series text messages to their parents.