The Link Between Antenatal Maternal Infections and Vaccine Immunogenicity in Children under 5 years in Sub-Saharan Africa: A Scoping Review Protocol

Objective: The objective of this scoping review is to use an iterative approach to systematically map the available evidence on the effects of maternal infections during pregnancy on vaccine immunogenicity in children under five years of age in sub–Saharan Africa. Background: Globally, vaccine-preventable infections are still implicated in a significant portion of childhood morbidity and mortality cases despite reported high vaccine coverage. Maternal infections during pregnancy, ranging from protozoan vector-borne diseases like malaria, to helminthic infections like schistosomiasis, viral infections such as HIV and CMV, have been shown to alter foetal immune development in-utero. The interplay of maternal infections, maternal immunity, and the developing foetal immune system could potentially affect early childhood immunogenicity and vaccine responses. Evidence from a preliminary database search hints at reduced antibody titres and altered cellular responses to routine childhood vaccines. This scoping review will map the existing evidence within sub-Saharan Africa on the nature of the interaction between maternal antenatal infections, in utero priming, and post-delivery infant vaccine responses. Inclusion criteria: This review will include published and grey literature, including children below the age of five in Kenya, any documented maternal infections during pregnancy, including but not limited to malaria, HIV, CMV, and schistosomiasis, and outcomes that reflect child vaccine responses and immunogenicity, including antibody titres, seroconversion rates, or any other immune markers. Methods: The proposed scoping review will be conducted in accordance with the methodology for scoping reviews suggested by the Joanna Briggs Institute (JBI) available from jbi.global proposed by Arksey and O’Malley in 2005 and revised by Levac et.. al in 2010. A fillable checklist will guide adherence to the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR). A comprehensive search strategy, developed and optimized via vibe coding using DeepSeek for PubMed, will be adopted for other databases, including Web of Science, African Index Medicus, and other relevant grey literature sources. Consideration will be given to studies published from January 2000 to the present. Two independent reviewers will screen the titles, abstracts, and full texts against a predefined inclusion criterion. Expected Outcomes: To determine which antenatal maternal infections have been studied in the Sub-Saharan African context regarding infant vaccine responses, which childhood vaccines have been evaluated in the same context, determine which immunological markers are used to define vaccine immunogenicity in under fives and create a geographical heat map showing which countries contribute evidence to this topic and where geographic gaps exist. Keywords: Child; Maternal Infection; Immunogenicity; Sub-Saharan Africa; Vaccine Response