NCT04544267

Study on a High-Dose Quadrivalent Influenza Vaccine Compared With Standard-Dose Quadrivalent Influenza Vaccine in Children 6 Months Through 35 Months of Age

Efficacy, Immunogenicity, and Safety of High-Dose Quadrivalent Influenza Vaccine Compared With Standard-Dose Quadrivalent Influenza Vaccine in Children 6 Months Through 35 Months of Age

• Status: Terminated
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 100 (actual)
• Sponsor: Sanofi Pasteur, a Sanofi Company · Industry
• Sex: All
• Age: 6 Months – 35 Months
• Healthy volunteers: Accepted

Summary

The primary objective of the study was to compare the clinical efficacy of high-dose quadrivalent influenza vaccine (QIV-HD) to standard-dose quadrivalent influenza vaccine (QIV-SD) in participants 6 months through 35 months of age for the prevention of laboratory-confirmed influenza illness caused by any influenza A or B type. The secondary objectives of the study were: * To compare QIV-HD to QIV-SD: * in participants 6 months through 35 months of age for the prevention of laboratory-confirmed influenza illness caused by any influenza A or B type using a more stringent threshold * in participants 6 months through 35 months of age for the prevention of laboratory-confirmed protocol-defined influenza-like illness caused by viral strains similar to those contained in the vaccine. * in participants 6 months through 23 months of age for the prevention of laboratory-confirmed influenza illness caused by any influenza A or B types. * To compare hemagglutination inhibition (HAI) immune response of QIV-HD to QIV-SD in participants 6 months through 35 months of age * To describe the HAI, seroneutralization (SN), and anti-neuraminidase (NA) immune response * To describe the immune response to revaccination in Season 3 (Northern Hemisphere) * To describe the safety profile of each vaccine

Detailed description

The study was planned to start in the second half of 2020 with the Sentinel Safety Cohort. Following the Sentinel Safety Cohort, the main efficacy cohort was to be conducted during the 2021-2022 Northern Hemisphere influenza season (Season 1), the 2021-2022 Southern Hemisphere influenza season (Season 2), and the 2021-2022-2023 Northern Hemisphere influenza season (Season 3). Participants received either 1 or 2 doses of the study vaccine depending on whether they were previously influenza vaccinated or previously influenza unvaccinated, respectively. Study duration per participant was approximately 6 to 7 months.

Conditions

• Influenza

Interventions

Type	Name	Description
BIOLOGICAL	Quadrivalent influenza vaccine, high-dose	Pharmaceutical form: suspension for injection in a pre-filled syringe; route of administration: intramuscular
BIOLOGICAL	Quadrivalent influenza vaccine, standard dose	Pharmaceutical form: suspension for injection in a pre-filled syringe; route of administration: intramuscular

Timeline

• Start date: 2020-09-15
• Primary completion: 2021-06-02
• Completion: 2021-06-02
• First posted: 2020-09-10
• Last updated: 2025-12-24
• Results posted: 2025-12-24

Locations

10 sites across 1 country: United States

Regulatory

• FDA-regulated drug study