FROM VACCINE
A school-based trivalent inactivated influenza vaccination program had a major impact on reducing school outbreaks of influenza in the Beijing area, said Yang Pan, PhD, of the Institute for Infectious Disease and Endemic Disease Control, Beijing Center for Disease Prevention and Control, and associates.
School-based trivalent inactivated influenza vaccination programs generally occurred Oct. 15-Nov. 30 each year since 2007, with greater than 50% vaccination coverage. In an 11-year retrospective study of school outbreaks of influenza in elementary, middle, and high schools in the Beijing area during Sept. 1, 2006-March 31, 2017, there were 286 febrile outbreaks in schools, involving 6,863 children.
A total of 81% were caused by influenza A/B virus (231 outbreaks), including influenza A(H1N1)pdm09 (58 outbreaks), A(H3N2) (123 outbreaks), B(Victoria) (46 outbreaks), and B(Yamagata) (4 outbreaks). A total of 17 outbreaks were negative for flu testing, and 38 failed in testing because samples were unavailable.
During the 11 years, a mismatch between circulating strains and vaccine strains was identified in two influenza seasons, such as “the A(H3N2) 3C.1 (vaccine strain)-A(H3N2) 3C.3a (circulating strains) mismatch in 2014-2015, the B(Yamagata) Clade 2 (vaccine strain)-B(Yamagata) Clade 3 (circulating strain) mismatch in the 2014-2015 influenza season, and B(Yamagata) (vaccine strain)-B(Victoria) (circulating strains) mismatch in 2015-2016,” they reported.
A combination of high flu vaccine coverage because of school-based vaccinations and a good vaccine match reduced influenza outbreaks in schools by 89% (odds ratio, 0.111), Dr. Pan and associates concluded.
“The school-based influenza vaccination program has been in operation for nearly 10 years in the Beijing area, is unique in China, and is one of the few school-based influenza programs in the world,” the researchers explained. “These data can inform and improve vaccination policy locally and nationally.”
Read more in Vaccine (2017 Nov 8. doi: 10.1016/j.vaccine.2017.10.096 ).
