ISIS does represent a real threat to Pope Francis but Vatican security officials do not believe an attack is currently being planned.
Domenico Giani, Commander of the Vatican Gendarmerie said in an interview with the Italian journal Modern Police that ISIS was not the only threat.
There were also risks from lone would-be assassins, and if anything they were harder to deal with because more unpredictable.
Last September the Iraqi ambassador to the Holy See, Habeeb Al-Sadr, warned that Pope Francis was "being targeted by ISIS" and said the threat to kill him was serious.
Earlier today, La Stampa in Rome reported that this had not gone away. Vatican Insider at La Stampa quoted Mgr Giani as saying: "The threat exists. This is what has emerged from the talks I have with Italian and foreign colleagues. But the existence of a threat is one thing, planning an attack is something else. At the moment I can say that we are not aware of plans to attack the Vatican or the Holy Father. "
He added: "The level of alert is consistently high, always appropriate in the circumstances. There is not only the threat posed by ISIS, but also the risks of solitary attacks, which are more dangerous because unpredictable. I am thinking of fanatics, the mentally disturbed, or simply individuals who may decide to take action against the Vatican for the media coverage that they can gain."
He said the challenge of ensuring the safety of a Pope who likes to make close contact with the people is particularly strong. The Pope does not wish to abandon the style of his pontificate, which is based on proximity, he said.
Pope Francis likes to make direct contract with as many people as possible, just as he did as a priest. "Therefore, as we are responsible for his safety, we have to adjust to him, and not vice versa. We must do everything so he can continue to carry out his ministry as he wants, and believes it should be."
He said the Pope was "well aware of the threat to his person, but his only concern is for the faithful. The Vatican is a place where every day, tens of thousands of people pass through, including visits to the Basilica, Museums, and hearings."
These people must feel relaxed and safe, he said.
He also spoke of "good cooperation" with Islamic countries. From these countries, he experienced "not come only valuable information, but also esteem and admiration for the Holy Father. I can say that today the Holy Father is seen and respected by Islam as the most influential moral authority in the world."
There are 130 Vatican bodyguards, although in light of the risk he felt there should be more. Budget constraints and austerity measures in the Vatican made this impossible.