This has resulted in a number of global outbreaks of vaccine-preventable diseases in first world countries.
The law is part of Italy's drive to increase vaccination rates to be in line with the World Health Organisation's target of 95% - enough to prevent diseases spreading while allowing children whose immune systems are too compromised for vaccinating to go without.
Italian health officials have taken a step towards stopping the wave of anti-vaccination campaigns.
The European Center for Disease Prevention and Control (ECDC) study after a major measles outbreak in the country in 2017 found that almost 89 percent of cases were reported among unvaccinated people.
Older children can attend school without being fully vaccinated, but parents face fines of 100 to 500 euros (C$151-754), and local health authorities will then schedule vaccinations for the children to make sure they get caught up.
After the notorious study by Dr. Andrew Wakefield that linked measles vaccine to autism, there has been rise in anti-vaccination sentiments among parents.
"No vaccine, no school", said Giulia Grillo, the health minister.
Children aged between 6 and 16 years can not be banned from school but their parents may have to pay fines up to €500 (£425) if their children are not vaccinated.
According to the BBC, Italy has fallen behind other countries in terms of vaccination rates. The waiver was heavily criticised by the scientific and medical community, which said it could reverse progress made in boosting Italy's vaccination rates in recent years.
"Italy's measles vaccine coverage was par with Namibia, lower than Ghana", San Raffaele University microbiology and virology professor Roberto Burioni told CNN previous year. Since yesterday, it has come into being. The "Lorenzin law", named after the former Italian health minister, requires kids to have 10 immunisations before attending school preventing illnesses including measles, mups, rubella, chicken pox and polio.