Researchers explore individuals' confidence or reluctance to vaccinate their families and the associated effects on global health, in a collection published by the open-access journal, PLOS Currents: Outbreaks. The collection is accompanied by the editorial "Hesitancy, trust and individualism in vaccination decision-making" by Jonathan E. Suk et al. from the European Centre for Disease Prevention and Control (ECDC).

Vaccines are thought to be one of the most successful public health measures, but some individuals are hesitant to vaccinate their families for a variety of reasons. Due to the current spread of vaccine-preventable diseases, including the most recent measles outbreaks in California and Berlin, Suk notes that the issue of vaccine hesitancy "appears to be increasingly pressing and politicized in many parts of the world." Peretti-Watel et al. and Larson et al. analyze the ambiguity of the language surrounding the terms vaccine hesitancy and confidence, and stress the importance of clarifying these terms when communicating about vaccinations. Other researchers examined how public trust in larger social structures and health systems correlates with the decision to vaccinate in both the United States and Europe. The collection also hones in on issues surrounding specific vaccines, including a paper that investigates US women's intentions to request the Tdap and influenza vaccines while pregnant, as well as an article about the H1N1 vaccination and how public communication affects individuals' perceptions of vaccines. Likewise, contemporary vaccination coverage is explored in Schuster et al., which relates to the ongoing measles outbreak in Berlin and its disproportionate effects in young adults.

While some articles address specific vaccination concerns, all wrestle with the issues that arise when even a small subset of vaccine-hesitant or resistant individuals potentially undermine immunization efforts. This leads to the question posed by Larson et al., "How much confidence [in vaccines] is enough?" Suk believes this is a significant question to explore as vaccine hesitancy remains an issue of both policy and personal decision.