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A phase IV study to investigate the immunogenicity of the Seqirus licensed MF59 adjuvanted zoonotic influenza vaccine (H5N8) in adults previously vaccinated in 2009 with the Matrix M adjuvanted virosomal influenza (H5N1) vaccine compared to H5 naïve adults.

Status
Recruiting
Phases
Phase 4
Study type
Interventional
Source
EU CTIS
Registry ID
CTIS2025-522593-36-00
Acronym
SEQVAC1
Enrollment
180
Registered
2025-09-30
Start date
2025-10-15
Completion date
Unknown
Last updated
2025-11-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Virus Diseases

Brief summary

Serum haemagglutination inhibition (HI) antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0) and 28 days after the first dose, and 28 days after the second dose (Day 56)., Serum microneutralisation (MN) antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0), 28 days after the first dose, and 28 days after the second dose (Day 56)

Detailed description

Serum HI antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) 7 days after the first dose, 7 days after the second dose (Day 35), Fold increase in serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), compared to baseline (Day 0), Serodetection, based on serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Seroconversion, based on serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), compared to baseline (Day 0), Seroprotection, based on serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Serum MN antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) 7 days after the first dose, and 7 days after the second dose (Day 35), Serum HI antibody titres against heterologous variant virus strains (including H5N1 clade 1 A/Vietnam/1194/2004 and H5N1 clade 2.2.1 A/turkey/Turkey/1/2005) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Fold increase in serum HI antibody titres against heterologous virus strains (including H5N1 clade 1 A/Vietnam/1194/2004 and H5N1 clade 2.2.1 A/turkey/Turkey/1/2005) 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 56), compared to baseline (Day 0), Serodetection, based on serum HI antibody titres against heterologous virus strains (H5N1 clade 1 A/Vietnam/1194/2004 and H5N1 clade 2.2.1 A/turkey/Turkey/1/2005) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Seroconversion, based on serum HI antibody titres against heterologous virus strains (including to H5N1 clade 1 A/Vietnam/1194/2004 and H5N1 clade 2.2.1 A/turkey/Turkey/1/2005) 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), compared to baseline (Day 0), Seroprotection, based on serum HI antibody titres against heterologous virus strains (including to H5N1 clade 1 A/Vietnam/1194/2004 and H5N1 clade 2.2.1 A/turkey/Turkey/1/2005) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Serum MN antibody titres against heterologous virus strains (including H5N1 clade 1 A/Vietnam/1194/2004 and H5N1 clade 2.2.1 A/turkey/Turkey/1/2005) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Occurrence of all serious adverse events (SAEs) from the day of vaccination up to the study end, Occurrence of all SAEs related to study intervention from the day of vaccination up to the study end

Interventions

Sponsors

Helse Bergen HF
Lead SponsorOTHER

Eligibility

Sex/Gender
All
Age
18 Years to No maximum

Design outcomes

Primary

MeasureTime frame
Serum haemagglutination inhibition (HI) antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0) and 28 days after the first dose, and 28 days after the second dose (Day 56)., Serum microneutralisation (MN) antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0), 28 days after the first dose, and 28 days after the second dose (Day 56)

Secondary

MeasureTime frame
Serum HI antibody titres against the vaccine virus strain (H5N8 clade 2.3.4.4b) 7 days after the first dose, 7 days after the second dose (Day 35), Fold increase in serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), compared to baseline (Day 0), Serodetection, based on serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), Seroconversion, based on serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) 7 days and 28 days after the first dose, and 7 days and 28 days after the second dose (Day 35, Day 56), compared to baseline (Day 0), Seroprotection, based on serum HI antibody titres against the virus strain (H5N8 clade 2.3.4.4b) at baseline (Day 0), 7 days and 28 days after the first dose, and 7 days and 28

Countries

Norway

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026