Assessment of Cross-Reactive Neutralizing Antibodies Induction Against H5N1 Clade 2.3.4.4b by Prior Seasonal Influenza Immunization in Retail Workers

Key Points

• No cross-reactivity against H5N1 was observed following seasonal influenza immunization in retail workers, indicating a lack of broader immunity.
• Despite strong neutralizing activity against seasonal strains, H5N1-specific antibodies were not detected in serum samples from the participants.
• The study used serum from retail workers to assess potential immunity to H5N1 viruses induced by prior seasonal influenza vaccinations.
• These findings highlight the need for targeted vaccines to elicit protective responses against H5N1, beyond current seasonal flu immunizations.