By: Elizabeth Do

Vaccine for the prevention of clostridium difficile infection passed evaluation to enter phase 3 trials after showing positive results in its phase 2 development. PF-06425090 vaccine (Pfizer) is designed to induce a functional antibody response that neutralizes disease-causing toxins produced by C. difficile, toxin A and toxin B. In August 2014, the FDA granted the vaccine fast-track designation to facilitate its development and to accelerate the review process.

Analysis revealed positive phase 2 data on the safety, tolerability and immunogenicity of the vaccine in more than 850 healthy adults aged 65 to 85 years. Two dose levels were evaluated (100 µg and 200 µg) and were administered during two different three-dose vaccination schedules at 1, 8, and 30 days, or at baseline, 1 month and 6 months. Despite its promising effects, increasing cases continue to rise with a negative impact on older adults thus propagating the urgent public health threat.

Clostridium difficile is a bacterium that causes inflammation in the colon and can be transmitted when the bacterium is shed in the feces. People can become infected when they touch surfaces contaminated with feces and then touch their mouth. Most cases are associated with healthcare as well as nursing homes or clinic patients where healthcare workers spread the bacteria to their patients if their hands are contaminated with the spores.  Approximately half of the infections occur in those older than 65 and account for 90% of the deaths. What makes C. difficile dangerous is their survival for long periods on surfaces. CDC advises that you wash your hands before eating and after using the bathroom, and to use a separate bathroom if you have diarrhea, or make sure that the bathroom is cleaned well if someone with diarrhea has used it. Infected patients should only take antibiotics as prescribed by their doctor. All surfaces that have been potentially contaminated should be carefully disinfected.

According to data released by the CDC, nearly half a million C. difficile infections occurred in the United States in 2011, where 83,000 recurred at least once and 29,000 were associated with death within 30 days of first diagnosis. Michael Bell, director of CDC’s Division of Healthcare Quality Promotion said, “In both nursing homes and hospitals, we’re seeing similar numbers of infections – about 100,000 each. Although people receiving care in hospitals make up two-thirds of all infections, two-thirds of those actually occurred after the patient went home.” With the approval of the FDA to fast-track the development of the vaccine, it addresses an important unmet medical need that could save thousands.