Comparing performance of year-round and campaign-mode influenza vaccination strategies among children aged 6-23 months in Kenya: 2019-2021

Jeanette Dawa; Rose Jalang'o; Harriet Mirieri; Rosalia Kalani; Doris Marwanga; Kathryn E Lafond; Mary Margaret Muriuki; Joyce Ejoi; Faith Chiguba; Shem Patta; Patrick Amoth; Emmanuel Okunga; Collins Tabu; Sandra S Chaves; Malembe S Ebama; Philip Muthoka; Virginia Njenga; Elizabeth Kiptoo; Isaac Jewa; Raphael Mwanyamawi; Joseph Bresee; M Kariuki Njenga; Eric Osoro; Lucy Mecca; Gideon O Emukule

doi:10.1016/j.vaccine.2023.11.036

Comparing performance of year-round and campaign-mode influenza vaccination strategies among children aged 6-23 months in Kenya: 2019-2021

Vaccine. 2023 Dec 16:S0264-410X(23)01380-4. doi: 10.1016/j.vaccine.2023.11.036. Online ahead of print.

Authors

Jeanette Dawa¹, Rose Jalang'o², Harriet Mirieri³, Rosalia Kalani⁴, Doris Marwanga³, Kathryn E Lafond⁵, Mary Margaret Muriuki⁶, Joyce Ejoi⁶, Faith Chiguba⁷, Shem Patta⁷, Patrick Amoth⁸, Emmanuel Okunga⁴, Collins Tabu², Sandra S Chaves⁹, Malembe S Ebama¹⁰, Philip Muthoka⁸, Virginia Njenga⁶, Elizabeth Kiptoo⁶, Isaac Jewa⁷, Raphael Mwanyamawi⁷, Joseph Bresee¹⁰, M Kariuki Njenga¹¹, Eric Osoro¹¹, Lucy Mecca², Gideon O Emukule⁹

Affiliations

¹ Washington State University (WSU) Global Health Kenya, Nairobi, Kenya. Electronic address: jdawa@cartafrica.org.
² National Vaccines and Immunisation Program, Ministry of Health, Kenya.
³ Washington State University (WSU) Global Health Kenya, Nairobi, Kenya.
⁴ Division of Disease Surveillance and Response, Ministry of Health, Kenya.
⁵ Influenza Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA.
⁶ Department of Health, Nakuru County, Kenya.
⁷ Department of Health, Mombasa County, Kenya.
⁸ Ministry of Health, Kenya.
⁹ Influenza Division, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA; Influenza Program, Centers for Disease Control and Prevention, Nairobi, Kenya.
¹⁰ Partnership for Influenza Vaccine Introduction, Task Force for Global Health, Atlanta, GA, USA.
¹¹ Washington State University (WSU) Global Health Kenya, Nairobi, Kenya; Paul G. Allen School of Global Health, Washington State University (WSU), Pullman, WA, USA.

PMID: 38105140
DOI: 10.1016/j.vaccine.2023.11.036

Abstract

Introduction: In 2016, the Kenya National Immunization Technical Advisory Group requested additional programmatic and cost effectiveness data to inform the choice of strategy for a national influenza vaccination program among children aged 6-23 months of age. In response, we conducted an influenza vaccine demonstration project to compare the performance of a year-round versus campaign-mode vaccination strategy. Findings from this demonstration project will help identify essential learning lessons for a national program.

Methods: We compared two vaccine delivery strategies: (i) a year-round vaccination strategy where influenza vaccines were administered throughout the year at health facilities. This strategy was implemented in Njoro sub-county in Nakuru (November 2019 to October 2021) and Jomvu sub-county in Mombasa (December 2019 to October 2021), (ii) a campaign-mode vaccination strategy where vaccines were available at health facilities over four months. This strategy was implemented in Nakuru North sub-county in Nakuru (June to September 2021) and Likoni sub-county in Mombasa (July to October 2021). We assessed differences in coverage, dropout rates, vaccine wastage, and operational needs.

Results: We observed similar performance between strategies in coverage of the first dose of influenza vaccine (year-round strategy 59.7 %, campaign strategy 63.2 %). The coverage obtained in the year-round sub-counties was similar (Njoro 57.4 %; Jomvu 63.1 %); however, more marked differences between campaign sub-counties were observed (Nakuru North 73.4 %; Likoni 55.2 %). The campaign-mode strategy exceeded the cold chain capacity of participating health facilities, requiring thrice monthly instead of once monthly deliveries, and was associated with a two-fold increase in workload compared to the year-round strategy (168 vaccines administered per day in the campaign strategy versus 83 vaccines administered per day in the year-round strategy).

Conclusion: Although both strategies had similar coverage levels, the campaign-mode strategy was associated with considerable operational needs that could significantly impact the immunization program.

Keywords: Coverage; Infants; Influenza vaccine; Policy; Program; Strategy; Target population.