Books about or involving vaccine hesitancy: a delay in acceptance or refusal of vaccines despite the availability of vaccine services. It is influenced by factors such as complacency, convenience, and confidence. Among the hesitant are "anti-vaxxer" groups; however, not all vaccine-hesitant are against vaccination. The term encompasses outright refusal to vaccinate, delaying vaccines, accepting vaccines but remaining uncertain about their use, or using certain vaccines but not others. Arguments against vaccination are contradicted by overwhelming scientific consensus about the safety and efficacy of vaccines.