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Reactogenicity of an Inactivated, Split-Virion Quadrivalent Influenza Vaccine in Infants and Children Aged ≥6 Months
Terry Nolan1,2, Frank R Albano3, Janine Oberije4
1Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3000, Australia.
Insights
Quadrivalent influenza vaccines (QIV) demonstrate a clinically acceptable safety and tolerability profile in children aged 6 months to 9 years. Studies showed mild to moderate adverse events, with no serious safety concerns identified in pediatric populations.
Area of Science:
- Pediatric Vaccinology
- Immunology
- Public Health
Background:
- Children are highly susceptible to influenza infections and can transmit the virus to vulnerable individuals.
- Quadrivalent influenza vaccines (QIV) offer protection against four influenza strains, with potential for enhanced efficacy during mismatched seasons.
Purpose of the Study:
- To evaluate the reactogenicity and safety of QIV in children aged 6 months to 9 years.
- To compare adverse events across different vaccine batches over two influenza seasons.
Main Methods:
- A safety and reactogenicity study of QIV (Afluria Quad and Afluria Quad Junior) was conducted in children aged 6 months to <9 years.
- Solicited local and systemic adverse events (AEs) were monitored for 7 days post-vaccination across two Southern Hemisphere influenza seasons (2019, 2020).
Main Results:
- Most solicited AEs were mild to moderate, with no significant batch variations observed.
- No serious AEs or AEs of special interest, such as anaphylaxis or febrile convulsions, were reported within 7 days post-vaccination.
- Overall AE rates were consistent with previous pediatric QIV studies.
Conclusions:
- QIV exhibits a clinically acceptable safety and tolerability profile in children aged 6 months to <9 years.
- The findings support the routine use of QIV in pediatric populations for influenza prevention.
Background:
Children are at high risk of influenza infections and may spread the disease to vulnerable family members. Quadrivalent influenza vaccines (QIV) provide protection against four strains of influenza recommended annually by the World Health Organization (WHO) and have the potential to provide improved protection during seasons with B-strain mismatch between vaccine and circulating virus strains.
Methods:
We evaluated the reactogenicity and safety of a QIV (Afluria Quad and Afluria Quad Junior, Seqirus, Parkville, Australia) in children aged 6 months to <3 years and 3 to <9 years over two Southern Hemisphere influenza seasons (2019 and 2020). The rates of solicited local and systemic adverse events (AEs) occurring on Days 1-7 after each vaccine dose were compared between three vaccine batches during each of the two seasons.
Results:
Overall, 73.7% of participants aged 6 months to <3 years and 77.5% of those aged 3 to <9 years reported any solicited AE between Day 1 and 7 of SH2019, and 66.7% and 69.2%, respectively, reported any solicited AE in SH2020, consistent with results from prior paediatric studies of QIV. The majority of solicited AEs were mild to moderate in severity. No consistent patterns of batch variation in solicited local or systemic reactogenicity were observed, suggesting no clinically significant differences between vaccine batches. No serious AEs or AEs of special interest (i.e., anaphylactic reaction or febrile convulsion) were reported during Days 1-7 after each vaccination, and no new safety concerns were identified.
Conclusions:
Together, these results support a clinically acceptable safety and tolerability profile of QIV in children aged 6 months to <9 years.
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