“It's easier to deal with the vaccines you know than the ones you don't know”: A qualitative study on healthcare workers' vaccine confidence in Nigeria

Vaccination is a cost-effective public health intervention that has saved many lives and improved well-being [1]. Between 2011 and 2020, over 20 million deaths were believed to have been averted due to vaccinations in GAVI supported countries [2]. Moreover, globally, Carter et al. estimated additional 51 million deaths are expected to be prevented from vaccines between 2021 and 2030 [3]. Yet, despite the importance of vaccines, there have been concerns about low uptake of vaccines globally [4,5]. This concern was accentuated during the COVID-19 pandemic. Waning vaccine confidence has been recognized as a leading threat to global health [[6], [4], [5]]. Vaccine hesitancy has been defined as a delay in acceptance or refusal of vaccines, despite their availability [7]. It is a complex social phenomenon, which may vary by vaccine type, context, and time [8]. In contrast, vaccine confidence is trust in vaccines, providers, and the processes and policies behind vaccine recommendation [7,9]. Building trust in vaccines is needed to reduce vaccine hesitancy. Healthcare workers are a trusted source of information about vaccines, and they play an important role in shaping public perception and confidence in vaccines [10,11]. However, studies have shown that vaccine confidence is waning among healthcare workers [[12], [13], [14], [15]]. As healthcare workers are central to immunization program delivery, decreasing vaccine confidence among them can have far-reaching negative effects on vaccine uptake. Nigeria has the second highest number of zero-dose children in the world [6]. Parts of Nigeria also have a long history of low vaccine confidence [16,17]. The most notable example is the boycott of the polio vaccine in 2003 in Northern Nigerian, where the population refused uptake due to concerns around vaccine contamination with infertility agents, HIV, and cancerous agents [18,19]. Reasons for the boycott stemmed from multiple complex factors: i) long standing distrust of biomedical medicine; ii) concerns around the US wars in the Middle East; iii) not trusting anything free; iv) a Pfizer clinical trial failing to follow ethical approvals; v) broad political distrust [18,19]. Many of these same challenges have contributed to the current low vaccine confidence and uptake in Nigeria [19]. Specifically, COVID-19 vaccine confidence was observed as low among Nigerian healthcare workers. Some of the distrust could be attributable to the implementation challenges faced by the COVAX (COVID-19 Vaccines Global access) alliance's efforts to provide innovative and equitable access to the COVID-19 vaccine [20]. They failed to reach this laudable goal and generated increased distrust due to issues relating to vaccine nationalism and property rights. As newer vaccines have recently been rolled out or are planned in Nigeria (e.g. rotavirus vaccine in August 2022, HPV in 2023, and malaria in December 2024) [21,22], ensuring healthcare workers confidence in new vaccines is important for achieving rapid coverage. Despite their importance, there is limited literature on how healthcare workers from Africa, and Nigeria specifically, perceive vaccines today. This knowledge can support the development of theoretical frameworks on healthcare worker vaccine confidence, as well as interventions to improve their confidence in the existing and newer vaccines, along with eventually improving vaccine uptake overall. We therefore aimed to understand healthcare workers perception of existing and emerging vaccines, their concerns, or fears, reasons for these and how these influence their confidence in vaccines.