Two Belgian couples were sentenced to a five-month prison sentence for refusing to comply with Belgium’s mandatory polio vaccine for children. In addition, each parent was fined 4,100 euros (more than $6,300).

The Belgian government mandates that children be vaccinated for polio, but not for other infectious diseases. Exceptions are granted only if a parent can prove his or her child will have an allergic reaction (unlike the United States, where most states allow parents to opt out for religious or philosophical reasons).

The Belgian couples can still reverse the prison sentence if they have their children vaccinated.

“Nobody has the right to unfettered liberty, and people do not have a right to endanger their kids,” said John Harris, a professor of bioethics at England’s University of Manchester, who also said the parents “have obligations they are not fulfilling” (Associated Press).

Polio has been largely eradicated in Europe since the World Health Organization (WHO) began widespread vaccinations in the late 1980s, though there is controversy on whether it was the vaccine that led to polio’s decline.

While polio is generally under control in Europe, outbreaks are common in Afghanistan, India, Nigeria and Pakistan. However, experts do not believe Belgium’s strategy for vaccine enforcement would help these nations. Dr. David Heymann, the top polio official for WHO, told AP, “It is up to individual countries to decide their own policies, but we do not feel imprisonment will help.”