Immune responsiveness in the neonatal period

Area of Science:

• Immunology
• Vaccinology
• Reproductive Biology

Background:

• Pregnancy necessitates maternal immune suppression to tolerate the fetus, shifting immune responses towards a Th2 phenotype.
• Newborns inherit a Th2-skewed immune environment, influenced by maternal factors and antibodies.
• Neonatal vaccination must overcome maternal antibody interference and the inherent Th2 bias for effective immunization.

Purpose of the Study:

• To investigate the potential of immune stimulatory complexes (ISCOMs) as adjuvants for neonatal vaccination.
• To evaluate the ability of ISCOMs to redirect neonatal immune responses towards a Th1-dominant profile.
• To assess the efficacy of ISCOM-adjuvanted vaccines in inducing protective immunity in neonatal animal models.

Main Methods:

• Viral antigens were incorporated into ISCOMs to create novel vaccine formulations.
• Immune responses in neonatal mice were analyzed, focusing on IgG subclass production and cytokine profiles.
• The induction of cytotoxic lymphocytes and protective immunity was assessed in neonatal mice and larger animal models (cattle, horses, dogs).

Main Results:

• ISCOM adjuvants induced balanced Th1 and Th2 immune regulation in neonatal mice.
• Evidence of balanced immune response included specific IgG subclass patterns and cytokine profiles.
• ISCOM-adjuvanted vaccines successfully induced protective immunity in newborns of various species.

Conclusions:

• ISCOMs are effective adjuvants for overcoming neonatal immune suppression and Th2 bias.
• ISCOM-based vaccines can elicit appropriate Th1-regulated immune responses for protection against infectious diseases in newborns.
• This approach shows promise for improving neonatal vaccination strategies across different mammalian species.