VATICAN CITY - The low-frills style of Pope Francis is having an effect on the upcoming canonizations of Popes John Paul II and John XXIII.

Organizers of the event said last week the April 27 saint-making ceremony is going to be a much more sober affair than the three-day extravaganza that accompanied John Paul's 2011 beatification.

That 2011 event included a prayer vigil on Rome's Circus Maximus field for tens of thousands of people and ended up costing several times the original estimate of $1.65 million.

No such vigil is planned this time around.

Cardinal Agostino Vallini, the vicar of Rome, said churches in Rome's center will remain open overnight before the canonization to provide a spiritual retreat for pilgrims, "but not much else."

"What's important that happens is that there's a sobriety, to get to the essential," said Vallini's communications director, Monsignor Walter Insero.

Italian news reports have said as many as 5 million or 7 million people may flock to Rome for the period surrounding the canonization, which also includes the busy Easter week before it and the May 1 holiday afterward.

The Vatican spokesman the Rev. Federico Lombardi played down the number of people who might attend the canonization itself, noting that about 250,000 can fit in St. Peter's Square and the main boulevard leading to it.

Lombardi also declined to confirm if emeritus Pope Benedict XVI might attend. Francis has encouraged Benedict to play a greater role in the public life of the church, and Benedict made a surprise cameo during the recent installation of 19 new cardinals.