Sex: U
Vaccine: FLUX
Symptoms: Encephalitis
Clinical narrative: This case was reported in a literature article and described the occurrence of encephalitis in a child subject who received Flu seasonal TIV Quebec. On an unknown date, less than a month after receiving Flu seasonal TIV Quebec, the subject developed encephalitis. Serious criteria included GSK medically significant and other: as per author. The outcome of encephalitis was unknown. The investigator considered that there was a reasonable possibility that the encephalitis may have been caused by Flu seasonal TIV Quebec. Additional information was provided: This case was reported in a literature article and described the occurrence of encephalitis in a child of unspecified gender aged 6 months who was vaccinated with unspecified trivalent inactivated influenza vaccine (IIV3) (manufacturer unknown). The patient was part of weekly post licensure surveillance conducted between 29 June 2014 to 9 April 2015 for seven prespecified adverse events (acute disseminated encephalomyelitis, anaphylaxis, Bell's Palsy, encephalitis, Guillain-Barre syndrome, febrile seizures, and transverse myelitis) following receipt of influenza vaccines during the 2014-2015 seasons in the Vaccine Safety Datalink using the electronic health record data from multiple integrated healthcare organizations. This surveillance aimed to evaluate the safety of influenza vaccines annually administered to people greater than or equal to 6 months. In this surveillance, adverse event outcomes were monitored following only the first doses for all influenza vaccines. The outcomes monitored were clinically well defined with relatively acute onset, and serious enough to results in a medical visit. In this surveillance, the post-vaccination risk intervals for each outcome were chosen based on their biologic plausibility and the prior literature. No information on patient's medical history or family history or concurrent condition or concomitant medication was provided. On an unspecified date during 2014-2015 season, the patient received 1st dose of IIV3 (administration route and site unspecified; batch number not provided). The trivalent IIV (IIV3) for 2014-2015 contained antigens from an A/California/7/2009 (H1N1)-like virus, an H3N2 virus antigenically like the cell-propagated prototype virus A/Victoria/361/ 2011, a B/Massachusetts/2/2012-like virus. On an unspecified date, between 1 and 21 days after vaccination with IIV3, the patient was detected in the surveillance with encephalitis. This case was considered serious due to author reported seriousness. Treatment was unknown. The outcome for the event was not reported. The authors considered the event of encephalitis related to IIV3. The authors concluded "In summary, an elevated risk of febrile seizures in the 0-1 days following the first dose IIV3 was identified during the 2014-2015 season in children aged 6-23 months in the VSD. In an analysis combining the data from two seasons the relative risk of febrile seizures comparing exposed to unexposed time periods was significantly elevated for IIV3 and IIV4 with concomitant PCV13 vaccination and not for IIV3 or IIV4 alone. Similar findings have been observed in previous seasons. No new safety concerns were identified in influenza vaccine safety surveillance during 2013-2014 and 2014-2015 seasons in the VSD. The VSD will continue to monitor the safety of influenza vaccines in future influenza seasons". This is 1 of the 4 valid cases reported in the same literature article.