Near-Complete SARS-CoV-2 Seroprevalence among Rural and Urban Kenyans despite Significant Vaccine Hesitancy and Refusal

• Type of Material: Article
• Authors: Carolyne Nasimiyu, Washington State University; Isaac Ngere, Washington State University WSU; Jeanette Dawa, Washington State University WSU; Patrick Amoth, Kenya Ministry of Health; Ouma Oluga, Nairobi Metropolitan Services; Carol Ngunu, Nairobi Metropolitan Services; Harriet Mirieri, Washington State University; John Gachohi, Washington State University; Moshe Dayan, Washington State University; Nzisa Liku, Washington State University; Ruth Njoroge, Washington State University; Raymond Odinoh, Washington State University; Samuel Owaka, Kenya Medical Research Institute; Samoel A Khamadi, Kenya Medical Research Institute; Samson L Konongoi, Kenya Medical Research Institute; Sudi Galo, County Government of Kakamega; Linet Elamenya, County Government of Kakamega; Marianne Mureithi, University of Nairobi; Omu Anzala, University of Nairobi; Robert Breiman, Emory University; Eric Osoro, Washington State University; Kariuki M Njenga, Washington State University
• Language: English
• Date: 2023-01-01
• Publisher: MDPI
• Publication Version: Final Published Version
• Copyright Statement: © 2022 by the authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/vaccines11010068
• Title of Journal or Parent Work: VACCINES
• Volume: 11
• Issue: 1
• Grant/Funding Information: This research was funded by the US National Institute of Allergy and Infectious Disease/National Institutes of Health (NIAID/NIH), grant number U01AI151799, through the Centre for Research in Emerging Infectious Diseases—East and Central Africa (CREID-ECA), the Consortium of Global International Agricultural Research/International Livestock Research Institute (CGIAR/ILRI) Research Program on Livestock, Rockefeller Foundation, Africa—Centers for Disease Control and Prevention. Carolyne Nasimiyu was supported by the Fogarty International Center and NIAID/NIH under grant number D43TW011519.
• Keywords: Research & Experimental Medicine; vaccine refusal; Immunology; Life Sciences & Biomedicine; Medicine, Research & Experimental; SARS-CoV-2 seroprevalence; vaccine hesitancy; herd immunity; Science & Technology; COVID-19 vaccine
• Research Categories: Health Sciences, Public Health; Health Sciences, Medicine and Surgery

Abstract

Considering the early inequity in global COVID-19 vaccine distribution, we compared the level of population immunity to SARS-CoV-2 with vaccine uptake and refusal between rural and urban Kenya two years after the pandemic onset. A population-based seroprevalence study was conducted in the city of Nairobi (n = 781) and a rural western county (n = 810) between January and February 2022. The overall SARS-CoV-2 seroprevalence was 90.2% (95% CI, 88.6–91.2%), including 96.7% (95% CI, 95.2–97.9%) among urban and 83.6% (95% CI, 80.6–86.0%) among rural populations. A comparison of immunity profiles showed that >50% of the rural population were strongly immunoreactive compared to <20% of the urban population, suggesting more recent infections or vaccinations in the rural population. More than 45% of the vaccine-eligible (≥18 years old) persons had not taken a single dose of the vaccine (hesitancy), including 47.6% and 46.9% of urban and rural participants, respectively. Vaccine refusal was reported in 19.6% of urban and 15.6% of rural participants, attributed to concern about vaccine safety (>75%), inadequate information (26%), and concern about vaccine effectiveness (9%). Less than 2% of vaccine refusers cited religious or cultural beliefs. These findings indicate that despite vaccine inequity, hesitancy, and refusal, herd immunity had been achieved in Kenya and likely other African countries by early 2022, with natural infections likely contributing to most of this immunity. However, vaccine campaigns should be sustained due to the need for repeat boosters associated with waning of SARS-CoV-2 immunity and emergence of immune-evading virus variants.