Novel vaccine aims to eradicate polio

Poliomyelitis was effectively eradicated from WHO European region in 2002 but elsewhere in the world 1294 new cases were recorded in 2010, with the highest incidence in India, Pakistan, Afghanistan and Nigeria.

Complete eradication of the disease is one of the goals of the Bill & Melinda Gates Foundation which has funded a number of projects with this aim in mind.

The University of East Anglia team will work with colleagues from Queen’s University, Belfast, to develop a novel way of vaccinating people against polio.

Professor Simon Carding, of UEA’s Medical School, is leading the project. “The vaccine currently in use includes oral delivery of attenuated strains of the virus itself and has reduced efficacy in children living in poor environments. There have been outbreaks actually caused by the vaccine. This leads to an unwillingness to be vaccinated, which is a double whammy as you really need to aim to vaccinate 90 per cent of individuals in order to establish herd immunity and for the population as a whole and, in particular, children, to be protected,” he said.

Polio is acquired via contaminated water, food and insanitary conditions – and the vaccine needs to be delivered orally to get into and protect the gastro-intestinal tract, which is the route by which the virus gains entry into the body.

Professor Carding and Professor Tom Wileman (also of the Norwich Medical School) are adapting a method of drug delivery that they have previously developed and which has already proved successful in treating inflammatory bowel disease.

“Our system involves delivering a bacterium that normally resides in everyone’s large bowel which we will engineer to produce the vaccine containing bits of virus particles in response to a sugar called xylan. Xylan is extracted from husks of rice and from wheat and can be administered in a drink,” said Professor Carding.
“On exposure to the xylan in the drink, the bacterium starts to produce the vaccine antigens to which the gut immune cells respond and provide protection against infection by polio virus.”

The £100,000 grant will enable the researchers to find out if the vaccine works effectively against the viral disease, how long immunity would last and what the dose should be. If this first phase is successful, it will go to clinical trials and could be in use in three to four years’ time.

The project starts on 1 September. Work on the vaccine will take place at the University of East Anglia, while testing will be undertaken by Professor Louise Cosby in Belfast.