Preschool-located influenza vaccination and influenza-like illness surveillance: an Italian pilot experience

Background We describe the first school-located influenza vaccination campaign with quadrivalent live-attenuated influenza vaccine (LAIV) among pre-school children in Italy, coupled with an innovative school-centred influenza-like illnesses (ILIs) surveillance using a self-sampling non-invasive saliva collection method.

Methods The pilot study was proposed during the 2021/2022 influenza season to fifteen pre-schools in the Milan municipality.

LAIV was offered directly in school to all healthy children without contraindications.

ILI differential diagnosis was conducted by real-time RT-PCR for influenza A/B and SARS-CoV-2.

Results Five pre-schools were involved in the pilot project and overall, 135 families (31.2%) participated in the study, adhering to both surveillance and vaccination; 59% of families had an immigrant background.

No pupil experienced adverse reactions after vaccination.

Nineteen saliva samples were collected from sixteen children (11.8%).

Six samples (31.6%) tested positive for SARS-CoV-2; none was positive for influenza A/B. Conclusions The participation in the immunisation campaign was good, considering possible absences due to COVID-19 pandemic, and the intranasal administration was well tolerated and helped to overcome parental hesitancy.

Saliva sampling represented a useful tool to reduce children’s stress and increase parents’ compliance.

The high participation of families with an immigrant background suggests that school-based interventions can represent an effective strategy to overcome socioeconomic and cultural barriers.