Distinct Longitudinal Antibody Responses Following Primary Influenza Infection or Vaccination in Infants: A Prospective Birth Cohort Study

Maternal immunization is a promising approach to provide influenza protection to newborns and infants, as their immune systems are still developing. Researchers conducted a study using pregnant and lactating ferrets to assess the effectiveness of an adenovirus type 5-vectored H1N1 hemagglutinin vaccine delivered via different routes: intranasally, intramuscularly, or through the gastrointestinal tract.

While all three administration methods led to a strong antibody response in the ferrets, the intranasal route proved to be the most advantageous. It not only raised influenza-specific antibodies in the dam's serum, respiratory secretions, and milk but also ensured efficient transfer to the suckling kits. This suggests that intranasal immunization effectively boosts functional influenza-specific antibodies in both the mother and her offspring, leading to improved protection for the newborn ferrets.

By focusing on mucosal immune induction through intranasal administration, this research emphasizes the potential benefits of enhancing maternal antibody responses, transfer to the infant, and overall neonatal defense against influenza.