These include patients with weak immune systems or those taking medication for other conditions that puts them at higher risk of death from Covid-19, the ministry said.
Numerous European countries declined to authorise the AstraZeneca vaccine to people over 65, citing insufficient evidence. However a raft of recent positive studies on the vaccine have led to many reversing that decision.
Italian Health Minister Roberto Speranza had announced the AstraZeneca decision on Sunday, as part of the government's drive to speed up vaccinations.
Like other European countries, Italy's drive to protect its population against the coronavirus has been met with supply shortages.
So far, the country has injected 5.4 million doses of the vaccine and given the required two jabs to 1.65 million people.
Speranza said the government aimed to fully vaccinate "at least half of our population" -- some 30 million people -- by the end of June.