Previous adult studies


Sanofi Pasteur sponsored a Clostricium difficile toxoid vaccine trail to enroll a total of 16,500 participants worldwide.

C. difficile diarrhoea is an important target for prevention through vaccination, given the increasing recorded cases worldwide, antibiotic resistance and recurrence of infection. Over 8 years of clinical research approximately 900 participants had received this potentially preventative vaccine and no safety concerns had been identified. The aim of this particular study was to assess the efficacy, safety and immunogenicity of this new potential C. difficile vaccine in subjects at risk of C. difficile infection. Participants received 3 injections within 30 days.

C. difficile is a very common bacterium that can live in the human gut. Some people have it without having any symptoms, but in others it can cause illness ranging from mild diarrhoea to severe colitis (infection of the colon). In some cases, C. difficile infection results in death.

C. difficile spores (seeds that can grow into the active bacteria under the right conditions) can live outside the body for long periods of time, on all kinds of surfaces, and can be easily spread from patient to patient in hospitals and nursing homes. Therefore, hospital patients and nursing home residents are at higher risk for C. difficile infection. Patients who are taking antibiotics are at even higher risk, because C. difficilebacteria in the gut are usually controlled by the presence of other, harmless bacteria. If those “good” bacteria are killed by antibiotics, theC. difficile bacteria may start to grow and produce toxins (substances made by the bacteria) that cause disease. The C. difficile bacteria are resistant to most antibiotics. Sometimes C. difficile infection can be controlled simply by stopping the antibiotic that was responsible for bringing it on. However strong antibiotics may be needed to clear up symptoms and about 1 out of 5 people have recurrent C. difficile infections requiring more medical care and long term antibiotics.

CONSTANT study (Clinical trial to evaluate a new Hepatitis B vaccine )

Hepatitis B is a serious infection of the liver caused by HBV that is spread through blood and other body fluids, and affects millions of people worldwide. Long-term (chronic) infection with HBV can lead to liver failure, cancer and even death. Once HBV infection has become chronic, treatment options are limited, therefore a better option is to prevent HBV infection by using vaccines.

This study is being done to compare an “investigational” HBV vaccine against a “standard” HBV vaccine (Engerix-B®) that is already licensed in the United Kingdom (UK), to measure whether it is as good as the currently used vaccine. The study will also compare three lots of the study vaccine (produced at different times), to ensure that the vaccine quality is consistently good.

Approximately 3,200 healthy people aged 18-45 years who have not previously been vaccinated against HBV will be enrolled in this study at up to 40 study sites in the UK, US, Canada, and the EU. The study will last for about a year, and will involve a screening visit and five study visits, plus four telephone check-ups. Participants will receive three doses of vaccine over the course of the study, and be asked to provide blood samples on 5 occasions.