A vaccine to prevent Crohn’s Disease

What this research looked at

MAP (Mycobacterium Avium subspecies Paratuberculosis) is a type of bacteria. MAP can be found in dairy foods, undercooked meat and drinking water. It’s thought that humans can be infected with MAP by eating or drinking infected food or water.

MAP is known to cause Johne’s disease. Johne’s disease, also known as paratuberculosis, affects cattle, sheep, and other livestock. There are similarities between Johne’s disease and Crohn’s. MAP is found more commonly in people with Crohn’s than people who do not have Crohn’s. MAP is not often found in people with Colitis. Scientists are studying whether infection with MAP might cause Crohn’s to develop. This may be more likely in people with certain genes.

It’s difficult to detect MAP in the body and there’s no standard test available. This makes it hard to know how many people with Crohn’s have MAP in their gut. MAP infection is treated with antibiotics. These antibiotics must often be taken for many months or years. Some studies show that anti-MAP antibiotics can help people with Crohn’s go into and stay in remission. But these studies are mostly low quality. Treating MAP is not currently recommended as routine treatment for Crohn’s.

This research looked at testing the effectiveness and safety of an anti-MAP vaccine in mice.

What the researchers found

The researchers created an anti-MAP vaccine by combining a virus with proteins from the MAP bacteria. Adding MAP proteins to the virus tricks the body into thinking the virus is MAP. This causes the body to create a response that fights against MAP.

The researchers found that the vaccine worked against MAP infection in mice and prevented further infection.

Crohn’s & Colitis UK provided funding for this project in 2005.

How this research has developed since

This research has continued to progress and is in the early phases of testing in humans. In people without any health conditions, it was found to be safe with no serious side effects. Funding for the research undertaken in humans has not been provided by Crohn’s & Colitis UK.

Researchers will continue testing the vaccine in people with active Crohn’s to see if it is safe and effective. This study is now complete, and the results of the research are due to be published in 2024.

What could this mean for people with Crohn's or Colitis?  

While it’s possible that MAP could trigger Crohn’s in some people, none of the research so far has been able to prove this. Targeting MAP may benefit some people with Crohn’s, but it probably won’t be an effective treatment for everyone. And there’s no evidence that it could cure Crohn’s. We recognise the importance of MAP research and welcome the development of new treatments for people with Crohn’s or Colitis.

Scientific Publications

A Novel Multi-Antigen Virally Vectored Vaccine against Mycobacterium avium Subspecies paratuberculosis. A Novel Multi-Antigen Virally Vectored Vaccine against Mycobacterium avium Subspecies paratuberculosis | PLOS ONE

Immunity, safety and protection of an Adenovirus 5 prime - Modified Vaccinia virus Ankara boost subunit vaccine against Mycobacterium avium subspecies paratuberculosis infection in calve. Immunity, safety and protection of an Adenovirus 5 prime - Modified Vaccinia virus Ankara boost subunit vaccine against Mycobacterium avium subspecies paratuberculosis infection in calves | Veterinary Research | Full Text (biomedcentral.com)

Safety and Immunogenicity of a Novel Recombinant Simian Adenovirus ChAdOx2 as a Vectored Vaccine. Safety and Immunogenicity of a Novel Recombinant Simian Adenovirus ChAdOx2 as a Vectored Vaccine - PMC (nih.gov)

Safety and Immunogenicity of Adenovirus and Poxvirus Vectored Vaccines against a Mycobacterium Avium Complex Subspecies. Safety and Immunogenicity of Adenovirus and Poxvirus Vectored Vaccines against a Mycobacterium Avium Complex Subspecies - PubMed (nih.gov)

Registered Trials

A phase I clinical trial to investigate the safety, tolerability and efficacy of two candidate Mycobacterium avium subspecies paratuberculosis (MAP) vaccines in patients with active Crohn's disease ISRCTN - ISRCTN36126048: A phase I clinical trial to investigate the safety, tolerability and efficacy of two candidate Mycobacterium avium subspecies paratuberculosis (MAP) vaccines in patients with active Crohn's disease

Who led the research: Professor John Hermon-Taylor
Funding: £89,242
Grant reference: M05/5 
Official title of application: Progress in the development of a prime/boost Ad5/MVA vectored vaccine against Mycobaterium avium subspecies paratuberculosis (MAP) to treat MAP-infected Crohn’s disease sufferers