title: Uptake and Effectiveness of a Trivalent Inactivated Influenza Vaccine in Children in Urban and Rural Kenya, 2010 to 2012.
abstract: BACKGROUND
  In Africa, recent surveillance has demonstrated a high burden of influenza, but influenza vaccine is rarely used. In Kenya, a country with a tropical climate, influenza has been shown to circulate year-round, like in other tropical countries.
  
  
  METHODS
  During 3 months in 2010 and 2011 and 2 months in 2012, the Kenya Medical Research Institute/Centers for Disease Control and Prevention-Kenya offered free injectable trivalent inactivated influenza vaccine to children 6 months to 10 years old in 2 resource-poor communities in Kenya-Kibera and Lwak (total population ~50,000). We conducted a case-control study to evaluate vaccine effectiveness (VE) in preventing laboratory-confirmed influenza associated with influenza-like illness and acute lower respiratory illness.
  
  
  RESULTS
  Of the approximately 18,000 eligible children, 41%, 48% and 51% received at least 1 vaccine in 2010, 2011 and 2012, respectively; 30%, 36% and 38% were fully vaccinated. VE among fully vaccinated children was 57% [95% confidence interval (CI): 29% to 74%] during a 6-month follow-up period, 39% (95% CI: 17% to 56%) during a 9-month follow-up period and 48% (95% CI: 32% to 61%) during a 12-month follow-up period. For the 12-month follow-up period, VE was statistically significant in children <5 years and in children 5 to <10 years old (50% and 46%, respectively).
  
  
  CONCLUSIONS
  In Kenya, parents of nearly half of the eligible children <10 years old chose to get their children vaccinated with a free influenza vaccine. During a 12-month follow-up period, the vaccine was moderately effective in preventing medically attended influenza-associated respiratory illness.
authors.affiliation: From the *US Centers for Disease Control and Prevention-Kenya; †Ministry of Public Health and Sanitation, Government of Kenya; ‡Kenya Medical Research Institute/Centers for Disease Control-Kenya; §University of Nairobi, Nairobi, Kenya; ¶Centers for Disease Control and Prevention-Atlanta; and ‖Emory University, Atlanta, Georgia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Katz
authors.forename: Emmaculate
authors.initials: E
authors.lastname: Lebo
authors.forename: Gideon O
authors.initials: GO
authors.lastname: Emukule
authors.forename: Nancy
authors.initials: N
authors.lastname: Otieno
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Caselton
authors.forename: Godfrey
authors.initials: G
authors.lastname: Bigogo
authors.forename: Henry
authors.initials: H
authors.lastname: Njuguna
authors.forename: Philip M
authors.initials: PM
authors.lastname: Muthoka
authors.forename: Lilian W
authors.initials: LW
authors.lastname: Waiboci
authors.forename: Marc-Alain
authors.initials: MA
authors.lastname: Widdowson
authors.forename: Xiyan
authors.initials: X
authors.lastname: Xu
authors.forename: Moses K
authors.initials: MK
authors.lastname: Njenga
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Mott
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
mesh_terms: D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D049674:History, 21st Century; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D007630:Kenya / Q000453:epidemiology; D008297:Male; D032541:Mass Vaccination; D017063:Outcome Assessment, Health Care; D011159:Population Surveillance; D012424:Rural Population; D014505:Urban Population
chemical_list: D007252:Influenza Vaccines