Antwerp researchers close in on new polio vaccine

Two years after 30 people spent a month in quarantine to test out polio vaccines, the University of Antwerp has revealed encouraging results in the fight to eradicate the disease.

In 2017, researchers at UAntwerp unveiled Poliopolis (pictured), a container village created to house two groups of people in strict conditions while they tested out two potential polio vaccines. The results of that study have now been published in medical journal The Lancet – from the first tests, the candidate vaccines appear to be safe and efficient, suggesting the definitive eradication of polio is within reach.

Polio is an inflammation of the spinal cord caused by a virus spread through the faeces of infected people, frequently due to poor hygiene or contaminated food and water. It is a crippling and potentially deadly disease without a cure, but as a result of routine vaccination programmes it has been largely wiped out in most parts of the world. In the 1980s there were 400,000 cases per year globally; today this figure is closer to 30 and cases are found only in Afghanistan, Pakistan and Nigeria. In Belgium, childhood inoculation against the disease is compulsory.

To eradicate polio entirely, vaccination rates in developing countries must increase further and a new vaccine is needed. “The oral vaccine used today in developing countries has achieved a lot but it carries a risk,” says professor Pierre Van Damme of UAntwerp’s Centre for Vaccine Evaluation, which led the study and is now carrying out further research. “In one out of every million vaccinations, it causes polio itself, and in regions with a low vaccination rate it can undergo mutations, so that the vaccine virus can again become pathogenic.”

There is an urgent need for the new oral vaccine, which is genetically more stable. “Compared to the number of naturally occurring polio cases, which remains more or less stable each year, we see the number of cases caused by vaccine viruses rising slightly,” says Van Damme. “If we want to help beat polio, we need to ensure the vaccine we’re using to fight it can no longer cause the disease itself.”

Two follow-up studies are now being carried out on the candidate vaccines examined in the Poliopolis study. Van Damme’s team and colleagues from Ghent University are testing them on a group of 332 adults, while 600 children have been vaccinated in Panama, so by the end of 2019 the researchers will have data from various age groups. It will then be up to the World Health Organization to decide how and when the new vaccines will be introduced – possibly as early as next year.

Photo courtesy UAntwerp