News

Hunting Down a C difficile Vaccine

Researchers test a potential vaccine that may help prevent thousands of deaths per year related to C difficile infection.


 

Could a vaccine help prevent infection with Clostridium difficile (C difficile), which causes thousands of deaths every year? In a first-in-human phase 1 study, researchers compared 3 doses of an investigational vaccine with placebo. The vaccine consisted of toxoids A and B (the principle virulence factors of C difficile-associated disease), and given with or without aluminum hydroxide in doses of 50, 100, or 200 μg at 0, 1, and 6 months.

Related: Antimicrobial Stewardship in an Outpatient Parenteral Antibiotic Therapy Program

The vaccine was well tolerated and effective. Local reactions and systemic events—mostly injection site pain, headache, and fatigue—were predominantly mild to moderate. Increasing the dosage or number of doses did not affect the frequency and severity of adverse effects, as reported by the participants in e-diaries.

Both the toxin A- and toxin B-specific neutralizing antibody levels increased from baseline. The first dose produced “modest” increases, but the second dose produced “marked” increases and the third dose had a “substantial” booster response, the researchers say. The booster response against toxin A was similar in both age groups tested (50-64 years and 65-85 years); the response against toxin B was the same or slightly higher in the older group.

Related:Hospital-Acquired Infections on the Decline

Overall, antibody responses were higher in the toxoid-only groups. The researchers note that aluminum salts have been used to enhance vaccine responses for decades and it was somewhat unexpected in this study that the toxoid-only vaccine led to better antibody responses.

While the study was limited by the small number of participants, the researchers say, the robust response and persistence of immune response to 12 months support further investigation.

Source:
Sheldon E, Kitchin N, Peng Y, et al. Vaccine. 2016;34(18):2082-2091
doi: 10.1016/j.vaccine.2016.03.010

Recommended Reading

A New Kind of Flu Drug
Federal Practitioner
New Developments in Adult Vaccination: Challenges and Opportunities to Protect Vulnerable Veterans From Pneumococcal Disease
Federal Practitioner
Flu vaccination found safe in surgical patients
Federal Practitioner
A Better Postexposure Anthrax Vaccine?
Federal Practitioner
HPV Vaccine Uptake Low Among Native Americans
Federal Practitioner

Related Articles