Uptake and Effectiveness of a Trivalent Inactivated Influenza Vaccine in Children in Urban and Rural Kenya, 2010 to 2012. Issue 3 (March 2016)

• Record Type: Journal Article
• Authors: Katz, Mark A.; Lebo, Emmaculate; Emukule, Gideon O.; Otieno, Nancy; Caselton, Deborah L.; Bigogo, Godfrey; Njuguna, Henry; Muthoka, Philip M.; Waiboci, Lilian W.; Widdowson, Marc-Alain; Xu, Xiyan; Njenga, Moses K.; Mott, Joshua A.; Breiman, Robert F.
• Is Part Of: Pediatric infectious disease journal. Volume 35:Issue 3(2016)
• Publication Date: 2016-03
• Subjects: influenza -- vaccine -- effectiveness -- respiratory -- Kenya; Communicable diseases in children -- Periodicals; Infection in children -- Periodicals; 618.929
• DOI: 10.1097/INF.0000000000001035
• Languages: English
• ISSNs: 0891-3668

Abstract

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.