Paediatric hospital visit with laboratory-confirmed influenza improved family members' influenza vaccination.

Objectives: Vaccination is the primary intervention to prevent influenza infection, yet vaccine uptake remains low among children and other at-risk patients. The aim of the study is to investigate the impact of a paediatric hospital visit with laboratory-confirmed influenza on the influenza vaccination behaviour of participants and their family members in the subsequent influenza season.

Methods: This study compared the influenza vaccination coverage for participants < 18 years of age with a clinical suspicion of influenza in 2017-2018 during a hospital visit, in two subsequent influenza seasons. Data was retrieved from the hospital electronic medical record and a follow-up questionnaire (2018-2019) to ascertain the common reason(s) that families did not vaccinate their children the following year (2018-2019). The children were distributed into positive- (antigen and/or PCR) and negative-influenza groups.

Results: A total of 133 children were enrolled in our study. Participants' mean age was 4.6 years and 74 (55.6%) were males. Overall, 47 (35.3%) had confirmed influenza virus. A significant increase in influenza immunization was found among both positive- and negative-influenza participants between 2017-2018 and 2018-2019 (6.4% vs. 27.7%, p < 0.001; 8.1% vs. 29.1%, p < 0.001, respectively), as well as among family members of positive-influenza participants - siblings and parents (6.4% vs. 19.6%, p = 0.003; 0% vs. 17%, p < 0.001, respectively). Common reasons for failure to vaccinate included doubt in vaccine effectiveness, unlikely to get "flu", busy, and side effects.

Conclusions: Our findings suggest that a paediatric hospital visit with laboratory-confirmed influenza increases vaccine uptake among families. Future studies should aim to evaluate evidence-based interventions to improve influenza vaccine uptake among children.