"A few dozen" infant school pupils in Sardinia's Cagliari province were not allowed to attend classes, a local official told Ansa. In the town of Elmas alone, some 40 children are said to have failed to produce vaccination certificates.
Another four cases were reported in Milan and four more at a single school in Sulmona, Abruzzo.
Some parents said they forgot or had not had time to get their children vaccinated, officials said, but at least two of the cases in Sulmona involve parents who refused vaccinations out of fear of supposed side effects.
Under Italy's mandatory vaccination law, all children who enrol at a state nursery or school must have receive shots against at least ten diseases. The Health Ministry had warned that all children aged six or under who hadn't had the vaccinations by March 10th, nor had an appointment to get them, would no longer be allowed to attend lessons.
Children sent home on Monday will be readmitted as soon as they have been vaccinated, officials said.
According to Ansa, an estimated 30,000 children across Italy hadn't received all ten vaccinations by last week.
However, the country's Higher Institute of Health, the ISS, said that Italy has achieved the goal of population immunity for some diseases and is making good progress towards it for others. More than 95 percent of children have received the combined vaccine that protects against six common diseases including tetanus, diphtheria, hepatitis B and polio, according to the head of the institute's department of infectious diseases, Giovanni Rezza.
Meanwhile vaccinations against measles are up by 6 percent, Rezza said, despite a rise in cases in 2017.
Italy recorded more than 5,000 measles infections last year, more than any other country in Europe except Romania. The increase prompted a warning from the World Health Organization, which expressed concern over the "anti-vax" movement that links certain vaccines to other health risks, despite scientific evidence to the contrary.
Italy was one of the countries where discredited claims of a link between the combined measles, mumps and rubella (MMR) vaccination and autism had a significant impact on public perceptions of the safety of the jab.
After the previous centre-left government introduced the vaccine law last year, its opponents made immunization a hot topic in the election campaign. Both the Five Star Movement and the League, the two forces with the best chances of forming a majority to govern after the March 4th election, promised to repeal at least some of the mandatory vaccine rules.