# Impact of Schistosoma mansoni Infection on the Gut Microbiome and Hepatitis B Vaccine Immune Response in Fishing Communities of Lake Victoria, Uganda

## TL;DR

This study explores how Schistosoma mansoni infection affects the gut microbiome and Hepatitis B vaccine response in Ugandan fishing communities.

## Contribution

The study reveals that S. mansoni infection may influence the relationship between gut microbiome diversity and vaccine effectiveness.

## Key findings

- S. mansoni infection was associated with higher Hep B vaccine responses.
- Higher gut microbiome alpha diversity showed a trend toward better vaccine responses.
- Older age was linked to lower Hep B vaccine responses.

## Abstract

Objective: Schistosoma mansoni (S. mansoni) infection is endemic in Ugandan fishing communities. We investigated its potential impact on Hepatitis B (Hep B) vaccine responses and its role in mediating the association between the gut microbiome and long-term effectiveness of the vaccine. Methods: Participants were tested for S. mansoni infections at baseline and received the Hep B vaccine at baseline, month 1, and month 6. Those with infections were treated. Stool samples were collected at baseline and analyzed using 16S rRNA sequencing. The Wilcoxon rank-sum test was used to compare alpha diversity between groups. A linear regression model was applied to estimate the association between one-year Hep B vaccine responses and the baseline gut microbiome by infection status, adjusting for age and sex. Results: A total of 107 participants were included (44 from the fishing community and 63 from the Kampala community). There was no significant difference in microbiome composition by location or infection status at baseline or discharge. In the linear regression analysis, S. mansoni infection (β = 1.24, p = 0.025) and a higher alpha diversity (β = 0.001, p = 0.07) were associated with higher Hep B vaccine responses, while older age was associated with a lower Hep B vaccine response (β = −0.06, p = 0.0013). Conclusions: S. mansoni infection status before vaccination may modify the association between the gut microbiome and Hep B vaccine response. Potential interventions could focus on infection control as well as improving microbiome richness before implementing vaccine programs in fishing communities.