Study timeline showing study design and participant loss to follow-up.

<p>Students and staff were consented, enrolled into the study and required to submit 3 stool samples, receive hepatitis B vaccine series and tetanus toxoid boost, submit to blood draws, and attend a Volunteer Counseling & Testing clinic. A total of 376 individuals signed consent forms with 146 individuals giving at least 2 blood samples thus meeting the study requirements for inclusion in analyses.</p

Individuals with schistosomiasis at the time of vaccination produced more IL-5 in response to in vitro tetanus toxoid stimulation compared to uninfected controls after vaccination.

<p>Whole blood cultures were stimulated in vitro with tetanus toxoid antigen for 72 hours and IL-5 was measured in the resulting supernatant fluids by ELISA at baseline, 6 weeks after boost and 8 months after boost. Circles represent study controls, individuals at baseline negative for <i>S</i>. <i>mansoni</i> and Soil Transmitted Helminths, and squares represent those schistosomiasis positive at baseline. Bars represent median IL-5 levels at each time point and statistical differences at each time point were determined using the Mann-Whitney test with a p < 0.05 considered significant.</p

Baseline characteristics of 146 participants who met all study requirements, completed at least baseline and first follow-up, as well as received tetanus boost and a minimum 2 of 3 hepatitis B doses.

<p>Baseline characteristics of 146 participants who met all study requirements, completed at least baseline and first follow-up, as well as received tetanus boost and a minimum 2 of 3 hepatitis B doses.</p

T regulatory cell (Treg) percentages (CD3⁺ CD4⁺ CD25^high cells) in peripheral blood are elevated in schistosomiasis infected individuals before praziquantel treatment and immediately following treatment.

<p>A. Whole blood was stained with anti-CD3-Alexa Fluor, anti-CD4-PercP and anti-CD25-PE and analyzed by flow cytometry at baseline, 1 week and 7 months following praziquantel treatment of schistosomiasis infected individuals and uninfected controls were followed at the same time points. CD25 expression was determined using a threshold based on florescence minus one (FMO) controls and used for all analyses with a CD25^high gate being set and used for all samples. Circles represent study controls, individuals at baseline negative for <i>S</i>. <i>mansoni</i> and Soil Transmitted Helminths, and squares represent schistosomiasis positive at baseline. Bars represent median Treg percentages at each time point and statistical differences at each time point were determined using the Mann-Whitney test with a p < 0.05 considered statistically significant. B. Treg percentages in controls at baseline, 7 weeks and 8 months did not change significantly over the study period as determined by the Friedman test followed by Dunn’s multiple comparisons. C. Treg percentages in Sm+ individuals increased significantly at 7 weeks, 1 week following PZQ treatment, as compared to baseline and 8 months as determined by the Friedman test followed by Dunn’s multiple comparisons.</p

Schistosomiasis infection at the time of hepatitis B vaccination results in reduced antibody titers to hepatitis B surface antigen.

<p>Anti-HbS levels were measured by ELISA before vaccination, 2 weeks after 2^nd vaccine dose, and 2 months after vaccine series completion with individuals with schistosomiasis being treated for their infection 1 week following 2^nd dose of hepatitis B vaccine. Box plots show the median, lower 25^th percentile, and upper 75^th percentile anti-HbS levels at each time point. Statistical differences at each time point were determined using the Mann-Whitney test with a p < 0.05 considered statistically significant.</p

Individuals in need of immediate tetanus toxoid boost with a concomitant schistosomiasis infection do not respond as robustly to vaccination as compared to individuals without schistosomiasis at the time of vaccination.

<p>Participants were allocated to groups based on their need for a vaccine boost as determined by their baseline titers: Immunize now < 0.1mIU/ml (A.); immunize within 1–2 years 0.1 to 1.0 mIU/ml (B.); Immunize 2+ years > 1.0mIU/ml (C.). Anti-tetanus toxoid (TT) titers were measured by ELISA at baseline, 6 weeks after boost, and 8 months after boost. Circles represent study controls, individuals at baseline negative for <i>S</i>. <i>mansoni</i> and STHs, and squares represent those who were schistosomiasis positive at baseline. Bars represent median anti-TT levels at each time point and statistical differences at each time point were determined using the Mann-Whitney test with a p < 0.05 considered statistically significant.</p

Percentage of participants falling into the catagories for hepatitis B virus exposure.

<p>Percentage of participants falling into the catagories for hepatitis B virus exposure.</p

Median and Interquartile Range (IQR, 25^th- 75^th percentile) of cytokine response (pg/ml) to 3 day whole blood culture with either tetanus toxoid or hepatitis B surface antigen.

<p>Median and Interquartile Range (IQR, 25^th- 75^th percentile) of cytokine response (pg/ml) to 3 day whole blood culture with either tetanus toxoid or hepatitis B surface antigen.</p