Uptake and Effectiveness of a Trivalent Inactivated Influenza Vaccine in Children in Urban and Rural Kenya, 2010 to 2012

Pediatr Infect Dis J. 2016 Mar;35(3):322-9. doi: 10.1097/INF.0000000000001035.

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.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Case-Control Studies
  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • History, 21st Century
  • Humans
  • Infant
  • Influenza Vaccines / adverse effects
  • Influenza Vaccines / immunology*
  • Influenza, Human / prevention & control*
  • Kenya / epidemiology
  • Male
  • Mass Vaccination
  • Outcome Assessment, Health Care
  • Population Surveillance
  • Rural Population*
  • Urban Population*

Substances

  • Influenza Vaccines