Schools in Italy are turning away children who have not received required vaccinations after a temporary waiver expired this week.

A 2017 law mandated children enrolled in Italian schools receive 10 different vaccines, the Times wrote, in “response to a worrisome decline in vaccinations nationwide and a measles outbreak that same year.”

However, last year the Health Ministry—headed by a member of the Five Star Movement political party, whose co-founder the paper noted has brought up conspiracy theories linking vaccination to autism—issued a temporary rule allowing parents to simply state the children had been vaccinated rather than receiving a note from a doctor.

The waiver was heavily criticized by the scientific and medical community, which said it could reverse progress made in boosting Italy’s vaccination rates in recent years.