SERIOUSNESS CRITERIA OTHER: IMPORTANT MEDICAL EVENT. Initial unsolicited report received from the literature on 30-Oct-2017. This case is linked with case 2017SA218009 (same reporter). Background. Some studies have found a higher frequency of fever with trivalent live attenuated influenza vaccine (LAIV) than with inactivated influenza vaccine (IIV), but quadrivalent LAIV has not been assessed. Understanding fever is important for safety reviews and for parents and providers. In addition, there have been only a limited number of studies in which text messaging was used for vaccine adverse-event (AE) surveillance. Methods. We conducted a prospective observational study in 3 community clinics to assess post-influenza vaccination fever in 24- to 59-month-olds during the 2013-2014 season. Enrolled families of children who received quadrivalent LAIV (LAIV4) or IIV (trivalent IIV3 or quadrivalent IIV4) replied to text messages that assessed their temperature on vaccination night and the next 10 nights (days 0 to 10); missing data were collected via telephone and a diary. We compared frequencies of fever (temperature 100.4 degree F) according to vaccine group on days 0 to 2 and 3 to 10 by using ?2 and multivariate log-binomial regression adjusted for age, previous influenza vaccination, and vaccine coadministration. We also assessed outcomes using all sources versus only text messages. Results. Most (84.1% [n = 540]) eligible parents enrolled. Fever frequencies on days 0 to 2 did not differ between LAIV4 and any IIV (3.8% vs 5.7%, respectively; adjusted relative risk [aRR] [95% confidence interval], 0.60 [0.25-1.46]), between LAIV4 and IIV4 (4.2% vs 7.1%, respectively; aRR, 0.58 [0.19-1.72]), or between IIV4 and IIV3 (7.1% vs 6.0%, respectively; aRR, 1.02 [0.30-3.46]). The findings were similar when all data sources versus text-message data alone were used. There were no significant differences on days 3 to 10. Conclusions: Post vaccination fever frequencies were low overall and did not differ according to influenza vaccine type during the 2013 2014 influenza seasons. The similarity of results when data were limited to text messages lends support to its use for surveillance of vaccine adverse events. This case involves a patient (age between 37 months to 59 months, gender not reported), who was vaccinated with INFLUENZA VACCINE (QUADRIVALENT IIV) (batch number, expiry date, dose, route were not reported) on an unknown date (in between September 2013 and April 2014). Patient's medical history and concomitant medication was not reported. On an unknown date in between day 3 to day 10 post vaccination, patient had fever (temperature greater than or equal to 102.2 degree F), five days after the vaccination, patient had an ambulatory care visit for an upper respiratory infection/allergy (started from an unknown date, after the vaccination) and ten days after the vaccination, patient had a visit on pediatric emergency department (PED) for pharyngitis/asthma (started from an unknown date, after the vaccination). Patient's other laboratory and corrective treatment was not reported. Outcome for the events were not reported. Upon internal review the case was considered as serious because of important medical event: upper respiratory infection. Documents held by sender: none. Sender's Comments: The patient experienced Upper respiratory infection, pharyngitis, suspected allergy and suspected asthma post vaccination with IIV4 (Quadrivalent inactivated influenza vaccine). Time to onset was compatible. No information regarding patient's medical history or tolerance to previous vaccinations was reported. There could be multiple etiologies for the vents ranging from infection via alternate sources to preexisting etiologies. Alternate etiologies should be ruled out before assessing the case. Based upon reported information the role for the vaccine cannot be assessed.