Nasal spray live attenuated influenza vaccine: the first experience in Italy in children and adolescents during the 2020–21 season

Abstract

Background In Italy only recently, for the 2020–21 season, has the flu vaccination been extended to all children. A quadrivalent live attenuated influenza vaccine (qLAIV) was administered to children aged 2–17 years for the first time. We registered the number and severity of adverse reactions to (Fluenz Tetra™) and the factors influencing them, evaluated uniformity of access to care and assessed the degree of satisfaction with the vaccination of both parents and health care providers, in order to improve the 2021–22 vaccination program. Methods On vaccination day, a questionnaire was given out to collect information about the children and their parents. Between 1 and 3 months later, the parents were contacted to record any adverse reactions following (Fluenz Tetra™) and rate the degree of satisfaction. Results We received data of 3226 children from 2152 families. Adverse events were reported in 24.8% of children: 80.6% mild, 18.1% moderate and 1.3% significant. The most common were rhinitis (52.5%) and fever (24.4%). Statistical analysis performed with a multiple regression model, showed that children aged 2–5 years have an increased risk of adverse events compared to both 6–10 years old (aRR 1.7, 95% CI 1.5–1.9, p < 0. 001) and 11–17 years old (aRR 1.5, 95% CI 1–2.2, p = 0.051). Most families chose to vaccinate their children to protect them and because they were concerned about Covid19. The main channel through which parents became aware of a new flu vaccination was word-of-mouth (39.8%), which occurred mostly among parents of the same school group, followed by information from the child’s doctor (30.6%), the Internet (26.9%), personal research (15%), newspapers (4%), telecommunications (7.5%) and other (2.6%). Most parents (83.3%) were very satisfied and intend to vaccinate their children with qLAIV again (83.8%). The majority of operators (93%) considered the experience as excellent and are willing to repeat it (94.6%). Conclusion (Fluenz Tetra™) proved to be easy to administer and the degree of satisfaction was high among both health workers and parents. Considering its substantial safety profile especially in school-age children and adolescents, all these aspects make the nasal qLAIV optimal for widespread immunization. Schools offer the best setting to reach more families and physicians should be actively involved.

Exploring the Negative Perceptions Influencing the Refusal of Flu Vaccination in the Older Adult Aged Greater than 60 Years Old: A Qualitative Systematic Review

“…To let the older adults, know the postvaccine side effects are manageable, leading to an increase in their willingness to be vaccinated. Also, the government can consider promoting the nasal spray influenza vaccine to be an alternative if the older adults are worried about postinjection pain after vaccination [78].…”

Quadrivalent Live-Attenuated Influenza Vaccine in Milan preschools: an Italian experience of school-located flu vaccination within the 2022–2023 season

“…The first Italian study of using the qLAIV on 9292 children aged 2–18 years, during the 2020–2021 flu season, has confirmed its safety and ease of administration and a high degree of satisfaction among both health workers and parents was recorded [ 11 ].…”

Feasibility of intranasal delivery of thin-film freeze-dried, mucoadhesive AS01B-adjuvanted vaccine powders

“…Intranasal vaccine can induce specific immune responses not only systemically, but also in the mucosal secretions of the respiratory tract (Birkhoff et al, 2009), which is advantageous as many pathogens infect their hosts through the respiratory tract (Chavda et al, 2021). In fact, several nasal vaccines have been approved for human use around the world, including the FluMist Quadrivalent in the United States (US) (Suryadevara and Domachowske, 2014), Fluenz Tetra in the European Union (EU) (Gasparini et al, 2021), NASOVAC-S in India (Ortiz et al, 2015), a freeze-dried nasal live influenza vaccine (Ganwu ® ) by the Changchun BCHT Biotechnology in China, and recently a nasal Coronavirus disease 2019 (COVID-19) vaccine by Bharat Biotech in India. Those nasal vaccines are live (attenuated) influenza virus-based or adenovirus-based and are presented as a liquid suspension or a freeze-dried powder for reconstitution.…”