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Vaccine hesitancy and reported non-vaccination in an Irish pediatric outpatient population

journal contribution
posted on 11.11.2021, 11:44 by Sean O Whelan, Frank MoriartyFrank Moriarty, Lisa Lawlor, Kathleen M Gorman, Joanne Beamish
Vaccine hesitancy is defined as a delay in acceptance, or refusal, of vaccines, despite availability. It is a complex and context specific phenomenon and identified as a global health priority. The “Parent Attitudes about Childhood Vaccines” (PACV) questionnaire is a validated tool for identifying vaccine hesitancy. Our aim was to use the PACV to assess vaccine hesitancy and its relationship with reported non-vaccination in an Irish population, for the first time. Our participants were parents or caregivers of children attending general pediatric clinics in a tertiary pediatric hospital in Dublin, Ireland, between September and December 2018. In total, 436 participants completed the questionnaire. 5.5% of our population reported non-vaccination. Human papilloma virus and measles, mumps, rubella vaccines were the most commonly cited vaccines of concern (11.5% and 6.7%, respectively), and autism spectrum disorder was the most commonly side effect of concern (4.3%). Mean PACV score was 26.9 (SD 19.1), with a significant difference between non-vaccinators and vaccinators (53.2 vs 25.3, p<0.001). Safety and efficacy concerns were the major contributor to non-vaccination. 14.4% of our population were vaccine-hesitant using the conventional cut-off score, which increased to 22% when using an optimal cut-off which maximized sensitivity and specificity. The accuracy of the PACV score to identify non-vaccination was good (area under the ROC curve = 0.827), and the optimal cut-off had a high negative predictive value (98.5%).
Conclusion: PACV identified reported non-vaccination with high accuracy in our population. It may be useful to screen vaccine-hesitant parents who could benefit from interventions to improve uptake.
What is Known:
• Vaccine hesitancy is a leading threat to global health, with falls in vaccine uptake associated with disease outbreaks worldwide.
• The Parent Attitudes about Childhood Vaccines (PACV) questionnaire is a validated measure of vaccine hesitancy and correlates with non-vaccination in many populations.
What is New:
• This large study in a pediatric outpatient clinic setting represents the first use of the PACV in a Western European population to assess vaccination hesitancy.
• The PACV may be an effective way of screening a pediatric clinic population to identify vaccine-hesitant parents or caregivers for targeted vaccine promotion.



The original article is available at

Published Citation

Whelan SO, Moriarty F, Lawlor L, Gorman KM, Beamish J. Vaccine hesitancy and reported non-vaccination in an Irish pediatric outpatient population. Eur J Pediatr. 2021;180(9):2839-2847.

Publication Date

27 March 2021

PubMed ID



  • School of Pharmacy and Biomolecular Sciences

Research Area

  • Population Health and Health Services


Springer Science and Business Media LLC


  • Accepted Version (Postprint)