Italian parents have been told they must provide proof their children are vaccinated before they can go to school.
The news follows months of debates over compulsory vaccinations, both in Italy and other areas of the world.
The BBC report that the law came following an increase in measles cases, with officials saying vaccination rates have improved since it was introduced.
The deadline for certification was meant to be March 10, following a previous delay. However, as that was a Sunday, it was extended an extra 24 hours.
Parents may be fined up to €500 if they send their unvaccinated children to school, while kids under the age of six may be turned away if they are not vaccinated.
Under the new law, kids must receive a range of vaccinations before they attend school. These include vaccines for chickenpox, polio, measles, mumps and rubella.
According to the rules, children under six-years-old will be excluded from nursery and kindergarten if they don't have proof of vaccination.
While those between the ages of six and 16 cannot be banned from attending school, parents may face fines if they don't complete the mandatory vaccinations.
Health Minister Giulia Grillo told
La Republica that the rules were simple: "No vaccine, no school."
