VACS: VAccination disComfort Scale.

The vaccination of children is a crucial tool to protect both individuals and the world in general from various diseases and pathogens. Unfortunately, the vaccination procedure is not a pleasant one for all children, with many experiencing various levels of discomfort, sometimes reaching intolerable levels. In the first part of this work, we develop VACS, a tool that measures the discomfort children experience during vaccination. VACS takes into consideration the complete timeline of the vaccination experience from the perspective of the child, starting from the moment the child enters the doctor's office through to their departure, and also the complete range of manifestations of discomfort, ranging from moaning and crying to facial expressions and posture. Their discomfort is quantified as a number from 0 to 25, with zero corresponding to a smooth vaccination and 25 to maximal/unbearable discomfort. In the second part of the work, we apply VACS to 40 vaccinations of children aged 2 to 12. Our findings show that approximately 40% of the children do not face discomfort during vaccination, but for the rest discomfort of varying degrees is observed. We also find that doctors are content with their patients facing considerably higher discomfort levels than what the children themselves are willing to withstand: doctors are content with VACS values up to 19 whilst children start to suffer when the VACS value exceeds 11. Surprisingly, characteristics such as (a) gender, (b) whether the state's recommended vaccination program has been implemented in full, and even (c) prior negative vaccination experiences are found to be poor predictors of vaccination discomfort. Age on the other hand may be a factor, with younger children experiencing discomfort more often and more intensely; more research is required in order to validate this with higher confidence. The formulation of VACS opens the door for more systematic work towards the mitigation of vaccination discomfort for children.