Dozens of children were turned away from schools in various parts of Italy on Monday after a government immunization deadline expired at the weekend.
Authorities barred unvaccinated kids from kindergartens and elementary schools in the northern city of Milan, in the central Abruzzo region, and in the island region of Sardinia.
Some of the cases were due to parents refusing to immunize their children due to "no-vax" positions, according to ANSA news agency.
Italy has seen a dropoff in immunizations in recent years due to highly organized "no-vax" campaigns claiming that vaccines cause autism and that they are a plot hatched by greedy multinationals.
The populist Five Star Movement and the rightwing anti-immigrant League, the two winners of Italy's March 4 general election, have espoused "no-vax" positions in the past and oppose mandatory immunizations.
Last summer, the center-left government of Prime Minister Paolo Gentiloni made 10 vaccines mandatory and a pre-requisite for children to attend school.
Almost 5,000 people were infected with measles and 4 died of the highly contagious disease in Italy in 2017, according to the Health Ministry.
Measles has the potential for large outbreaks wherever immunization coverage has dropped below the necessary threshold of 95 percent of the population, according to the World Health Organization (WHO).
"The numbers show a rise in vaccinations, which was the objective of the (government) decree," ANSA quoted Superior Institute of Health (ISS) Contagious Diseases Department Director Giovanni Rezza as saying on Monday.
"We have surpassed the 95 percent vaccination rate, so the herd immunity threshold has been reached," Rezza said.
According to a survey of 3,130 Italian parents with kids aged 16-36 months published in January 2018, 83.7 percent of respondents said they are in favor of vaccines, 15.6 percent were "hesitant" and 0.7 percent were "no-vax", according to the ISS.