Vaccination Hesitancy and Its Impact on Immunization Coverage in Pediatrics: A Systematic Review

"Ultimately, the findings of this review will contribute to developing targeted strategies aimed at enhancing vaccination acceptance and ensuring the sustainability of immunization programs for children worldwide."

One significant global health issue that is present in more than 190 nations globally is routine vaccination reluctance. This systematic review aims to synthesise the evidence on vaccination hesitancy and its impact on immunisation coverage in paediatrics. By critically examining studies from diverse geographical and cultural contexts, this review seeks to provide a comprehensive understanding of the extent of the problem, its driving factors, and its implications for public health policies. 

A total of 4,085 articles were found through searches in four databases (PubMed, Scopus, Web of Science, and CINAHL). Only 23 of them passed the quality assessment and satisfied the inclusion/exclusion criteria; 29,131 parents, guardians, and other caregivers of children ages 0-6 from over 30 countries participated in the studies described in these 23 reports. The diverse geographical representation allows for a broader understanding of vaccination hesitancy in different cultural and socioeconomic contexts. All studies employed a cross-sectional design, except one study that utilised a mixed-methods approach. 

The key findings of the studies highlighted various aspects of vaccination hesitancy, which was found to be caused by factors such as cultural customs, rumours and myths, misconceptions, poor communication with physicians and other healthcare professionals, and perceived risks and problems with vaccines. Several studies reported a correlation between lower vaccine confidence and higher hesitancy. Some studies identified specific factors associated with hesitancy, such as lower parental education, concerns about vaccine safety, lack of trust in healthcare providers, and lower socioeconomic status. Other studies emphasised the role of effective communication strategies in addressing hesitancy and highlighted the importance of healthcare professionals as trusted sources of information. One study noted the influence of digital literacy and cyberchondria (a clinical condition in which repeated, excessive online searches regarding medical information result in heightened health anxiety) on vaccine hesitancy. Some studies also reported on the prevalence of vaccine delay and refusal and the impact of the COVID-19 pandemic on vaccine confidence.

These results highlight the importance of addressing demand-side factors related to socioeconomic determinants and supply-side issues such as improving health literacy, combating misinformation, ensuring clarity in communication, and promoting a consistent, evidence-based message. The studies collectively underscore the complex and multifaceted nature of vaccination hesitancy and the need for tailored interventions to address this public health challenge.

Per the researchers, the fact that many of the included studies employed different data collection instruments reduced the risk of heterogeneity but offered findings that were also informative. Due to the use of standardised tools, including the World Health Organization (WHO) SAGE Working Group on Vaccine Hesitancy's Vaccine Hesitancy Scale (VHS) and the Parent Attitudes About Childhood Vaccines (PACV) scale, comparisons could be made across populations and other contexts of the research. 

In conclusion: "More observations and studies should be done regularly to establish measures of promoting high uptake of the vaccines by children."