An observational descriptive study, including a non-controlled educational intervention, was conducted to evaluate the safety of the intranasal spray influenza vaccine (qLAIV) and the vaccine adherence among a sample of FPs operating in the Palermo LHA. The study was designed within a two phases project coordinated by the Hygiene Section of the Department of Sciences for Health Promotion, Maternal and Infant Care, Internal Medicine, and Excellence Specialties “G. D’Alessandro” of the University of Palermo, in collaboration with the Palermo LHA’s Health Department and the Provincial Section of the Italian Federation of Family Paediatricians.

Phase 1: introduction of qLAIV vaccination and formative intervention

The target of the formative intervention was represented by the 62 FPs practicing within the Palermo Local Health Authority (LHA).

The qLAIV vaccination, encompassing effectiveness, administration method, and safety aspects, was introduced during a continuing medical education event, hold on September 23rd, 2022, attended by 41 FPs out of 62 (Response Rate: 66.12%), recruited by the Palermo Section of the Italian Federation of Family Paediatricians (FPs). Before the formative intervention, participants received an anonymous questionnaire to be self-administered via a QR code on the Google® Module platform. The questionnaire aimed to previously explore willingness, acceptance, attitudes, and knowledge regarding paediatric influenza vaccination.

Following the formative session, information on the project’s rationale, qLAIV characteristics, other influenza vaccines available for the paediatric population, administration methods, organizational strategies, and the contents of the Sicilian regional recommendations for the seasonal influenza vaccination campaign 2022/2023, was provided.

Phase 2: active surveillance on qLAIV safety and vaccination adherence

Throughout the year, two brief online webinars were organized on January 11, 2023, and April 5, 2023, presenting ongoing epidemic and virological influenza trend during 2022/2023 season, including vaccinations administered in the Palermo LHA, preliminary data on active surveillance on adverse events reported by the participating FPs. Discussions also included data on responses to the initial questionnaire administered to FPs at the first event.

The project finished on June 16, 2023, with the presentation of data on the adherence to the seasonal vaccination campaign among the paediatric population in the study, as compared with the paediatric population of the Palermo LHA and Sicily, along with safety data collected via the surveillance system.

Active surveillance on qLAIV safety among vaccinated individuals and adherence to influenza vaccination in the paediatric population

In accordance with the Directive 2001/20/EC Art. 2, adverse events were defined as:

1.

serious unexpected adverse avent: a serious adverse reaction whose nature, severity, or outcome is not consistent with the reference safety information.

2.

serious adverse event: any harmful clinical event that, regardless of the dose, requires hospitalization or prolongs ongoing hospitalization, results in severe or prolonged disability or incapacity, results in a congenital anomaly or birth defect, is life-threatening, or causes death [15].

Parents actively participated in surveillance by completing a diary form, either at the time of the second dose or reporting via telephone to the paediatrician starting on the 10th day post-vaccination. The diary card, designed with detailed instructions for proper completion and organized into sections, functioned as a comprehensive tool.

It provided guidance on reporting expected adverse events, ensuring that parents were well-informed about events listed in the data sheet, thus facilitating prompt communication with their paediatrician.

Utilizing the same card, parents monitored specific adverse events based on the summary of product characteristics (SmPC) through eight questions.

This included investigating skin rash, headache, general malaise, muscle pain, and inappetence, specifying the intensity and duration of the symptoms. It also covered monitoring temperature, specifying degree and duration, and hypersensitivity reactions, specifying facial oedema, urticaria, other severe anaphylactic reaction, with respiratory or circulatory involvement.

All expected adverse events were to be indicated as absent, mild (mild symptoms that typically resolve within 24 h without the need for medications), moderate (moderate-intensity symptoms that generally resolve within 24 h with the administration of appropriate medications), or severe (severe symptoms that are typically resolved with the administration of medications within 72 h).

Simultaneously, they shared their perceptions of qLAIV compared to intramuscular vaccination, if previously administered, and offered insights for potential enhancements in future paediatric flu campaigns.

Indication and recommendation of qLAIV vaccine in accordance with SmPC and recommendations of Sicilian region for 2022/23 season

Children without contraindications to qLAIV vaccine, excluding patients under 24 months of age, allergic to egg proteins or gentamicin, immunosuppressed, or with severe asthma, were considered for the study. Ethical approval was obtained from the University Hospital of Palermo Ethical Committee (session of July 2022, protocol no. 07/2022).

Statistical analysis

The data obtained were uploaded in a Microsoft Excel® spreadsheet (which were also automatically generated by the Google ® Modules online questionnaire collection system by the FPs).

Data were distributed and summarized as means with their standard deviations. Absolute and relative frequencies were calculated for qualitative variables. Chi-squared tests (with Fisher’s correction, where appropriate) were used to compare categorical variables and especially to compare the significance of the increase in vaccination coverage rates between Sicily, Palermo, and the intervention group.

All the data were analysed using the statistical software package Stata/MP 14.1 (StataCorp LP, College Station, TX, USA).