Table 3.

5C psychological antecedents of vaccination scale constructs and definitions.

Construct	Definition
Confidence	“Trust in (i) the effectiveness and safety of vaccines, (ii) the system that delivers them, including the reliability and competence of the health services and health professionals, and (iii) the motivations of policy-makers who decide on the need of vaccines [5].”
Collective responsibility	“The willingness to protect others by one’s own vaccination by means of herd immunity. The flip side is the willingness to free ride when enough others are vaccinated. Collective responsibility should correlate positively with collectivism, communal orientation, and empathy. It should correlate negatively with individualism [7].”
Complacency	“Perceived risks of vaccine-preventable diseases are low and vaccination is not deemed a necessary preventive action [5].”
Constraints	Physical constraints include the “physical availability, affordability and willingness-to-pay, geo- graphical accessibility, ability to understand (language and health literacy) and appeal of immunization service affect uptake [5].” Psychological constraints deal with access and “a lack of perceived control [7]”.
Calculation	“Individuals’ engagement in extensive information searching. We assume that individuals high in calculation evaluate risks of infections and vaccination to derive a good decision [7].”