Participants in good health wanted for typhoid vaccine study

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You are invited to take part in a study to investigate typhoid fever and how the typhoid bacteria causes disease. The study, investigating typhoid fever pathogenesis (TYGER) – is being run by the Oxford Vaccine Group which is part of the University of Oxford.

If you are 18 to 60 yrs old, in good health and have not previously received a typhoid vaccine then you may be eligible to take part in the study. We will provide reimbursement for your time, inconvenience and travel. The total study participation time is 12 months.

Background

Typhoid fever is an infection caused by the bacteria Salmonella Typhi. Although typhoid fever is rare in the UK, it is a major problem in developing countries, affecting up to 22 million people and resulting in many deaths every year. Access to clean water and sanitation facilities could help to eradicate typhoid infection but this is difficult to implement in resource poor countries. Effective vaccines could help to control the spread to disease. Currently the typhoid vaccines that are available are only moderately effective and no vaccine is licensed for use in young children. More research is needed to better understand typhoid so that we can develop better typhoid vaccines.

Study goals

In this study we aim to understand more about the Salmonella Typhi bacteria and how it causes illness. Specifically we want to understand the importance of a toxin produced by the typhoid bacteria, called the Typhoid Toxin. Our goals are to better understand typhoid fever, develop new diagnostic tests and contribute to development of new vaccines against Salmonella Typhi.

We will be undertaking a ‘challenge’ with two strains of the typhoid bacteria (Salmonella Typhi). Participants will be exposed to live Salmonella Typhi under tightly controlled circumstances, by asking them to swallow a drink that contains the bacteria. After the challenge we will closely monitor participants for a period of two weeks, treating participants with antibiotics as soon as they show any symptoms of infection. This process has been undertaken by participants in previous Oxford Vaccine Group studies since 2011.

We will use two strains of the typhoid bacteria. Half of the participants (20) in this study will be challenged with a ‘normal’ strain of the typhoid bacteria, called wild-type strain, which has been used in earlier challenge studies. The other half of the participants (20) will be challenged with a modified’ strain of the typhoid bacteria that is not able to produce the typhoid toxin, called the toxin-negative strain. Previous studies show that by giving a specific dose of the wild-type strain of Salmonella Typhi, 60% to 70% of people exposed to the bacteria will develop typhoid infection. If fewer people are infected with typhoid after receiving the toxin-negative strain (less than 60%), then this suggests that typhoid-toxin, specifically, is important in causing typhoid disease

Further Information

The Oxford Vaccine Group, University of Oxford, is based in the Centre for Clinical Vaccinology and Tropical Medicine in the Churchill Hospital site. This study has been funded by the Bill and Melinda Gates Foundation.

Reimbursement

We will provide reimbursement for your time, inconvenience and travel.

Date required

Ongoing

Organisation

Oxford Vaccine Group, University of Oxford
Centre for Clinical Vaccinology and Tropical Medicine (CCVTM)
Churchill Hospital
Old Road, Headington
Oxford OX3 7LE

Contact

This study is being run by the Oxford Vaccine Group which is part of the University of Oxford. Contact details shown below:

Oxford Vaccine Group weblink: ovg.ox.ac.uk

Trial Weblink: trials.ovg.ox.ac.uk/trials/tyger

Email: info@ovg.ox.ac.uk

Phone: 01865 611400