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Testimonial Sarah Weltje

Published on
September 20, 2017

I am Sarah Weltje, and recently obtained my MSc. in Molecular Life Sciences. Via the laboratory of Nematology I have done an internship at the Texas Children's Hospital Center for Vaccine Development in Houston, in the U.S.A. I worked for Baylor College of Medicine, a health sciences and great biomedical research institute. My specific workplace was located in one of the many copper-brown Texas Childrens Hospital buildings. Though the TCH mainly is a non-for-profit pediatric hospital, it houses, and collaborates with multiple other companies and organisations. BCM is an academic hospital, offering specialised care and research and study programs amongst other things. Both are located in Houston’s Medical Center.

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BCM is currently developing multiple vaccines for neglected tropical diseases, such as helminthic diseases (human hookworm, schistosomiasis) and Chagas Disease (CD), but also viral diseases as West Nile and Chikungunya. Chagas Disease is a neglected tropical disease caused by the Trypanosoma cruzi parasite and transmitted by a Triatomine kissing bug. The disease is endemic in almost all South- and North American countries south of the Unites States, and is also on a more incidental basis spotted in Europe. For seven months, I studied and assisted in vaccine formulation of a recombinant Chagas antigen, under supervision from Dr. Jeroen Pollet.

My internship comprised of stability assessment of a Trypanosoma cruzi protein (to be used as vaccine) formulated with and without an oil-in-water squalene emulsion adjuvant. This emulsion is a good carrier a Lipid A Toll-like receptor  4 agonist capable of inducing a Th-1 immune response desirable for this type of vaccine. Usually the antigen in buffer and the adjuvant are mixed right before use. However, as CD is a disease of the poor, simply reducing the amount of material, transport costs and physician time by presenting one antigen-and-adjuvant vial instead of two, is viable. The adjuvant however is opaque and contains oil droplets. This presented new challenges for biophysical characterisation, as it is usually dependant on light, works best with single species assessment at a time, in similar quantities, with hydrophobic or hydrophilic properties not too far apart. Together with Dr. Pollet I created a methodology and assessed the formulated antigen using Dynamic Light Scattering, Size Exclusion Chromatography, Micro-Flow Imaging, and Western Blotting as most memorable techniques. My work showed stability of this vaccine combination for up to four months and has cleared (part of) the way for this vaccine for preclinical testing.

Getting into the U.S.A. was an administrative hassle; however, I was well assisted in this by Jeroen Pollet and former WUR. student Leroy Versteeg. I had previously never travelled alone and had not left Europe so naturally I was very excited and also slightly frightened. I was not disappointed; I had a great time discovering a similar culture with its very distinctive differences. Most Americans I’ve met have Europeans in high regard and are very curious what life is like outside of the States. Within BCM I enjoyed the active and friendly attitude of the department, with its weekly lectures and celebrational dinners but also the casual Taco-Tuesdays, the non-Renaissance related Renaissance festival, watching of the Super Bowl, spontaneous dinner parties and sometimes dubious and decadent lunch treats.