Vaccine hesitancy refers to the reluctance or refusal of individuals or communities to vaccinate themselves or their children despite the availability of vaccines. This phenomenon is influenced by a variety of factors, including concerns about vaccine safety, misinformation and mistrust of healthcare providers or pharmaceutical companies. Vaccine hesitancy can have serious consequences, including outbreaks of preventable diseases and public health crises. Researchers in this area seek to understand the reasons behind vaccine hesitancy and develop strategies to address and mitigate these concerns in order to improve vaccine uptake rates and protect public health.