On 12 March 2008, the Associated Press reported that two sets of Belgian parents who recently failed to vaccinate their children against polio were handed prison sentences by the Belgium government. Each parent was fined $8000 and given 5-month jail sentences.
Belgian law requires polio vaccination, and there are no exceptions (not even for religious reasons) EXCEPT if parents can prove that their child will have a serious adverse reaction to the vaccine.
France is the only other country that mandates polio immunization by law. Another case of required vaccination is during the annual Muslim Hajj pilgrimage in Saudi Arabia, where pilgrims must show proof of vaccination if arriving from polio-endemic areas.
Read more here: Jail for Belgians Who Reject Polio Shot