Last reviewed 2026-04-23 · How we verify

aH5N1c

aH5N1c is a vaccine that stimulates the body's immune response to the H5N1 subtype of the influenza A virus.

aH5N1c is a vaccine that stimulates the body's immune response to the H5N1 subtype of the influenza A virus. Used for Prevention of influenza caused by the H5N1 subtype of the influenza A virus.

At a glance

Mechanism of action

This vaccine works by introducing a piece of the H5N1 virus to the body, which triggers an immune response and helps the body develop antibodies to fight the virus. The vaccine is designed to provide protection against severe illness and death caused by the H5N1 virus.

Approved indications

• Prevention of influenza caused by the H5N1 subtype of the influenza A virus

Common side effects

• Pain, redness, or swelling at the injection site

Key clinical trials

• A Study to Evaluate Safety, Immunogenicity, and Lot-to-Lot Consistency of H5N1 Subunit Influenza Virus Vaccine in Healthy Adult Subjects ≥18 Years of Age (PHASE3)
• A Study to Evaluate Safety and Immunogenicity of One or Two Booster Vaccinations With H5N6 Influenza Vaccine in Adults Primed With H5N1 Influenza Vaccine or Unprimed (PHASE2)
• Safety and Immunogenicity of Two Doses of H5N1 Influenza Vaccine in Elderly Subjects (PHASE2)
• Safety and Immunogenicity of Two Doses of H5N1 Influenza Vaccine in Children (PHASE2)
• Safety and Immunogenicity of Two Doses of H5N1 Influenza Vaccine in Healthy Adults (PHASE2)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• aH5N1c CI brief — competitive landscape report
• aH5N1c updates RSS · CI watch RSS
• Seqirus portfolio CI