Document Type : Systematic review or meta-analysis
Authors
1
Université Abdou Moumouni, Niamey, Niger ; PB 10896, Niamey, Niger;
2
Centre de Formation et de Recherche en Médecine Tropicale (CFRMT), Niamey, Niger ; PB 10896, Niamey, Niger
3
Department of Medicine, Faculty of Health Sciences, Université Abdou Moumouni, Niamey, Niger
4
Department of Health Public, Faculty of Health Sciences, Université Abdou Moumouni, Niamey, Niger
5
Department of Biological Sciences, Université André Salifou, Niamey, Niger
6
Department of Applied Biological Sciences, Faculty of Health Sciences, Université Abdou Moumouni, Niamey, Niger
7
Department of Medicine, Faculty of Health Sciences, Université André Salifou, Niamey, Niger
8
Epicentre, Maradi, Niger ; PB : 13330, Maradi, Niger
9
Epicentre, 14-34 Avenue Jean Jaurès, Paris, France
10
Department of applied biological sciences, Faculty of Health Sciences, Université Abdou Moumouni, Niamey, Niger
Abstract
Background: The major challenges of vaccination programs are notably coverage in the target population, vaccine hesitancy and cost-effectiveness. Aim: This study aimed to review the literature on administering fractional vaccine doses in Africa. Methods: A systematic search of PubMed and Google Scholar was conducted to identify articles published up till March 31, 2024. Keywords used for the search were “fractional dosing”, “Vaccines”, and “Africa”. Results: Findings from eleven eligible studies were analyzed. Studies were from the Democratic Republic of the Congo, Gambia, Ghana, Kenya, South Africa, and Uganda. They covered five vaccines including the yellow fever vaccine (n=3; 27.3%), inactivated poliovirus vaccine (n=3; 27.3%), meningococcal A/C/Y/W135 vaccine (n=2; 18.2%), Haemophilus influenzae type b vaccine (n=2; 18.2%), and malaria vaccine (n=1; 9.1%). Fractionated doses used most often consist of one-fifth of the standard dose (n=8; 72.7%). Regarding immunogenicity/efficacity, eight of ten studies that addressed immunogenicity suggest that immune responses to the fractional dose vaccines were comparable to that of the standard dose vaccines and resulted in higher antibody titers. Regarding safety, all of the eight studies that addressed the safety of fractional doses in Africa, suggest that safety and tolerability data of fractional dosing were favorable compared to full dose regimen. Conclusion: Fractional dosing may be considered to address the availability and acceptability of certain vaccines while maintaining protection. Contribution: Although efforts are currently underway to increase the possibility of vaccine manufacturing on the African continent, fractional dosing strategies may also be needed in the future and potentially offer other benefits.
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