Vaccination for infectious diseases is a vital method of prophylaxis, and has transformed modern medicine. By contrast, research into vaccines against chronic diseases has been less successful, in part because of the increased complexity involved.

In this opinion piece, the authors outline the prospects for the development of chronic disease vaccines. These might not need to rely on the traditional method of inducing the body to produce antibodies, but rather on introducing monoclonal antibodies against specific proteins — this has so far worked well against Crohn's disease and rheumatoid arthritis.

The authors outline key hurdles in developing a successful therapeutic vaccine. Safety and efficacy are two obvious ones, but there is a third that is unique to vaccines for chronic diseases. Because these vaccines would block bodily chemicals — such as cytokines or hormones — it would not be acceptable for a vaccine to induce a life-long block (unlike a malaria vaccine, for example, where a lifelong block would be ideal).

These might be particularly useful in developing countries, say the authors. Because prophylaxis with vaccines is already a familiar concept, there should be no problem with patients' compliance, and judicious partnerships between public and private organisations could mean the vaccines are produced cheaply.