Human Nutrition and Oral Vaccine Efficacy

Area of Science:

• Immunology
• Public Health
• Nutrition Science

Background:

• Oral vaccines (OVs) significantly reduced infectious diseases but are less effective in low- and middle-income countries (LMICs).
• Factors like undernutrition, poor sanitation, and repeated enteropathogen exposure in LMICs create a 'tropical barrier' to OV efficacy.
• Micronutrient deficiencies (zinc, vitamins A, D, iron) further impair gut health and immune responses crucial for OV success.

Purpose of the Study:

• To review current understanding of how human nutrition impacts oral vaccine (OV) immunogenicity.
• To explore the link between diet, gut health, and vaccine response in LMIC contexts.
• To identify strategies for improving OV performance in global health settings.

Main Methods:

• Literature review synthesizing epidemiologic evidence, field interventions, and mechanistic studies.
• Analysis of factors affecting OV replication, immune response, and efficacy.
• Integration of data on nutritional status and gut environment in LMICs.

Main Results:

• Nutritional status is a key modifiable factor influencing OV performance.
• Undernutrition and micronutrient deficiencies disrupt gut homeostasis and immune development, hindering OV efficacy.
• Adverse environmental conditions in LMICs contribute to impaired OV response.

Conclusions:

• Human nutrition profoundly shapes oral vaccine (OV) immunogenicity.
• Addressing nutritional deficiencies and improving gut health are critical for enhancing OV effectiveness in LMICs.
• Strategies integrating nutritional interventions are needed to close global gaps in OV performance and reduce infectious disease burden.