PROTECT situational analysis finds critical research gap on maternal vaccine confidence and vaccine trial participation

Recent research by PROTECT partners investigated existing literature on maternal vaccine and vaccine trial confidence and found no studies on pregnant women’s willingness to participate in vaccine trials in sub-Saharan Africa. This critical gap in research reflects the limited number of such trials conducted in the region and points to an urgent need for research into pregnant women’s knowledge about and attitudes toward vaccine trial participation. 

Two of the authors – Lisa Paranthoen and Dr Violet Naanyu – explain how PROTECT aims to fill these research gaps. 

Critical research gap

“The scope of our review”, begins Lisa Paranthoen, “was to explore existing literature on vaccine confidence in pregnancy and the willingness to participate in vaccine trials. We focused on the four countries involved in the PROTECT project - Malawi, Mozambique, Uganda and Kenya - and sought to identify factors influencing vaccine trial confidence and hesitancy in pregnant women from the sub-Saharan region.” 

In addition to peer-reviewed research, the authors looked for the so-called grey literature—evidence not published in a scholarly journal—to capture insights from a broader range of sources. However, the grey literature they identified mainly consisted of "guidelines, vaccine recommendations, policies, and epidemiological reports," elaborates Paranthoen. No studies on pregnant women's willingness to participate in vaccine trials in sub-Saharan Africa emerged. 

Still, other important findings were made, reminds Dr Violet Naanyu, specifically “concerning maternal vaccine acceptance. Vaccine acceptability, levels of awareness and knowledge about maternal vaccines varied widely across countries. For us to increase vaccine confidence and vaccine trial participation, these factors require further (and contextual) investigations so that we can come up with acceptable and feasible interventions to enhance desired uptake behaviour.” 

Photo by Aleix Cabrera provided by ISGlobal.

Implications for maternal vaccine research  

PROTECT’s main aim is to lay the foundations for the decade of maternal vaccines, focusing on the GBS vaccine. This means that partners support medical sites in Kenya, Malawi, Mozambique, and Uganda to establish pregnancy registries and collect data on GBS disease burden. With better monitoring systems in place, these sites will be better able to participate in future maternal vaccine trials. 

“Pregnant women have been historically excluded from vaccine trials,” reminds Paranthoen, even though we know of the “disproportionate impact of these diseases on pregnant women and their foetuses.” To address health disparities, vaccine trials must become more inclusive – in terms of groups taking part as well as their geographical location. “Research on maternal vaccination in low- and middle-income countries is essential,” believes Paranthoen, “to address health disparities and ensure equitable access to life-saving vaccines.” 

“Maternal vaccine acceptance remains low globally,” adds Dr Naanyu, “and relevant data from the African settings are scarce. PROTECT tries to fill a very big and important gap. Understanding pregnant women’s environment (including social and economic), their knowledge, attitudes, and fears before maternal vaccine introduction can help inform demand-generation strategies that are needed to ensure successful trials.” 

The literature gap findings will guide the consortium’s ongoing efforts in understanding the drivers of vaccine confidence and vaccine trial participation. PROTECT researchers in the four African project countries are already starting to work with communities and gathering data to answer these questions. The purpose of this work, explains Paranthoen, is to “create the necessary dialogue with potential participants and the wider public to improve willingness to participate in vaccine trials and thus confidence in vaccines and vaccine trials in pregnancy.” 

Photo by Marta Solano provided by ISGlobal.

Context-specific solutions for vaccine trial participation hesitancy 

With all public health communication, a deep understanding of the context where it will be shared and thoughtful involvement of the public are key. The review’s findings confirmed this yet again, reminds Dr Naanyu, as they “highlight the complexity and heterogeneity of factors influencing maternal vaccine confidence in Africa. It reminds us about health knowledge gaps and potentially informs strategies to improve maternal vaccine confidence.” 

The review also established that once vaccine trials are carried out in a certain area, this experience helps build further vaccine confidence and trial participation. Researchers found that an important source of information about vaccines during pregnancy comes from “experienced peers”, meaning those who have been in a trial before. Their experience sharing is an important venue for trial participation and vaccine confidence. 

PROTECT partners are incorporating all these findings in their ongoing research efforts in Kenya, Malawi, Mozambique, and Uganda to gain better insight into the contexts in which pregnant women make decisions regarding vaccine trial participation and vaccine acceptance. They will then proceed with the co-creation of a communication and education toolkit that can be used to inform about these topics in low-literacy populations. 

Photo by Geraint Hill/Stitching Pictures.

Beyond PROTECT 

The project’s aims are ambitious, and the consortium is committed to accelerating the maternal vaccine research agenda in Africa. The effects will likely be seen beyond the project’s work as well.  

Dr Naanyu expresses her hopes regarding the effects of the review findings: “We found barriers and facilitators to vaccination during pregnancy, with contextual influences significantly impacting pregnant women’s willingness to accept vaccination. Efforts to enhance facilitators while addressing barriers ought to be funded and rolled out across Africa.”