Italians face tougher rules from today if they are not vaccinated against COVID-19.
The 'Super Green Pass' will require vaccination, rather than including those who have received a negative test result, and it will be needed to attend sports events, concerts, theatres, indoor restaurants, and public events.
The normal Green Pass, which can be obtained with a negative test result, will be acceptable for the use of local transport and hotels.
There are doubts, however, as to how the rules will be enforced on public transport, given how busy rush-hour trains and buses can be.
Healthcare workers already have to be vaccinated but, from 15 December, the rule will also include all school staff, police, and the military.
Booster jabs, currently available to those over 40, will be made available to those over 18.
Italy reported 43 new COVID-19 deaths on Sunday, along with 15,021 new infections - both down on the previous day's figures.
But it is among a number of countries concerned about the new Omicron variant, which is believed to be more transmissible than the current dominant Delta variant.
Watch: COVID-19 pass becomes mandatory for all workers in Italy - amid fears of unrest
Italy has reported more than five million cases since the pandemic began early last year and more than 134,000 deaths - Europe's second-highest death toll after the UK, and the world's ninth-highest.
Health worker Annamaria Di Capua told Reuters: "I know from my experience what we workers of the public health system have suffered and what people and citizens have suffered.
"Now any measure is necessary and useful."
Padua resident Sonila Cera told the news agency: "Being vaccinated, I want to go into a restaurant or somewhere else feeling safer. If those who are not vaccinated also come in, then I feel less safe."
Restaurant manager Paolo Nonnis added: "We make regular checks on customers who enter the restaurant and eat in the dining rooms with the QR code check.
"It's a good thing because it allows us to go ahead and work and allows people to use public services."
Elsewhere in Europe:
• The incoming German government wants to make COVID-19 vaccinations mandatory from mid-March for those working in hospitals, nursing homes, and other medical practices. It is thought people would also be given the opportunity to prove they have recovered from the virus, or to present a medical certificate proving they cannot be vaccinated.
• There have been more protests in Belgium against tighter COVID-19 restrictions. Most were peaceful but police used water cannon and tear gas to disperse a small group. New measures were announced on Friday, the third consecutive week that the government has brought in tougher rules. The latest include an early closure of day care and primary schools, mandatory masks for children from the age of six, and a limit of 200 people at indoor events.
• Romania reported its first two cases of the Omicron variant on Saturday - two Romanians who returned from South Africa on 30 November. The two, who were not travelling together, are isolating and have no symptoms, the health ministry said. Romania has the second-lowest level of vaccination in the EU.
• Spain is planning to vaccinate children aged five to 11 as soon as possible, with 1.3 million doses of Pfizer's paediatric vaccine due to arrive on 13 December. A further two million doses are expected next month.
Watch: COVID-19: Travel rules have changed again because of Omicron - what are they now?