PURPOSE: Introduced in 2010, Ireland's school-based HPV immunisation programme has shown lower vaccine uptake in disadvantaged DEIS (Delivering Equality of Opportunity in Schools) schools compared to non-DEIS schools. This study aims to determine if the HPV vaccine misinformation period (2015-2017) disproportionately affected DEIS schools. METHODS: This is a register-based cohort study that used routinely collected data on HPV vaccination uptake in girls only, combined with DEIS status from the Department of Education. The analysis covered six academic years (2013-2019), focusing on three periods: 1) Prior to vaccine misinformation (academic years 2013-2014/2014-2015), 2) During misinformation (academic years 2015-2016/2016-2017), and 3) Recovery (academic years 2017-2018/2018-2019). RESULTS: Overall HPV vaccination uptake was 84.8 % before the misinformation, dropped to 55.2 % during the misinformation, and increased to 72.9 % during the recovery period. The uptake difference between DEIS and non-DEIS schools was 4.5 % (95 % CI 1.80-7.17) before the misinformation, 8.0 % (95 % CI 5.35-10.68) during misinformation, and 12.4 % (95 % CI 9.80-14.91) in the recovery period, with DEIS schools showing reduced recovery compared to non-DEIS schools (64.5 % vs 76.5 %
p <
0.001). CONCLUSION: HPV vaccine misinformation disproportionately affected HPV vaccine uptake in disadvantaged schools. Tailored interventions are needed to address this disparity in DEIS schools.