Chaos has marred the start of the school year in Italy because of widespread confusion about the government’s policy on vaccines.

In Bologna about 1,000 children with impaired immune systems will be forced to stay away from school on Wednesday due to uncertainty over whether their classmates have received vaccines against viruses including measles.

There have also been cases across the country of parents falsely claiming that pre-school children have been vaccinated.

Legislation introduced by Italy’s previous leftwing administration made 10 vaccines mandatory for children enrolling in state-run schools, and required parents to provide a doctor’s certificate.

But in August this year the current government – made up of the far-right League and the populist Five Star Movement (M5S), which in the past has said, despite scientific evidence to the contrary, that vaccines are dangerous – passed an amendment allowing parents to self-certify instead of providing a doctor’s note. A final vote on that measure later this month is likely to postpone the obligation to provide proof until March 2019.

Last week – under pressure from regional authorities, parents’ groups and the Italian National Association of Principals (ANP) – the health ministry scrapped an earlier amendment that said unvaccinated children could still attend school, but it maintained the self-certification measure until next year.

“Parents can self-certify until March, during which time there is the danger of them making false claims,” said Antonello Giannelli, the president of ANP. “But the main danger is that we will oblige children who cannot be vaccinated because of health reasons to go to school with children who are not vaccinated because of ideological reasons.”

Pre-schoolers must be vaccinated, although their parents are not required to provide proof from a doctor. But children aged six to 16 are allowed to attend school even if they have not been vaccinated and their parents are fined up to €500 for not doing so.

The story of an eight-year-old boy from Treviso in northern Italy, who is recovering from treatment for leukaemia, made headlines on Tuesday after a doctor posted a message on Facebook saying he is not attending school due to fears his health will be compromised by five unvaccinated classmates.

“This is a moment of great confusion, which is very bad as this is a field that needs clarity,” said Roberto Burioni, a professor of microbiology and virology at the Vita-Salute San Raffaele University in Milan.

“People need to be confident of the fact that vaccines are safe, and are for the health of the community – to attend a gym in Italy you need to present a certificate of good health, so why should this be any different? With vaccinations you are gambling with lives. And making false claims is a crime.”

Burioni is a prominent pro-vaccination campaigner who this summer received threats from a small but virulent anti-vaccine movement which has been buoyed by the rise to power of the populist coalition.

“I really don’t know what the government’s strategy is, as things change from one day to the next, or why this confusion is being created … but maybe they are trying to be a bit nice to anti-vaxxers, who are few but very noisy, so they are able to scare others,” he added.

The mandatory vaccine law was brought in to boost immunisation coverage after a surge in the number of measles cases in the country. Last year Italy recorded 4,885 instances of the highly contagious disease, second in Europe behind Romania. So far this year there have been 1,700 cases and four deaths.

Italians’ perception of the safety of vaccinations was heavily influenced by now discredited claims of a connection between the combined measles, mumps and rubella vaccination and autism.

Anti-vaxxers are still spreading false claims as people die of measles | Helen Stokes-Lampard Read more

M5S politicians have previously claimed that vaccines can be as dangerous as the diseases they protect against, although before general elections in March the party toned down its message, saying it was not anti-vaccination but against obliging parents to have their children injected. Meanwhile, Matteo Salvini, the leader of the League, said in July that the requirement for 10 vaccines was “too much”.

“They very quickly change the political content of their platform according to changes in public opinion, and think there are no consequences, but of course this is not the case,” said Massimiliano Panarari, a politics professor at Luiss University in Rome.