VATICAN CITY —Pope John Paul II presided over the traditional Corpus Christi procession on May 30, his first liturgical event since returning from his trip to Azerbaijan and Bulgaria.

He appeared so weak on that trip that a German journalist traveling on the papal plane said the press corps was on constant “red alert” for a medical emergency.

Returning to Rome apparently had a restorative effect. John Paul was able to read his full text at the Wednesday audience and then his homily for Corpus Christi —the solemnity of the Body and Blood of Christ.

When speaking Polish or Italian the Holy Father is clearer and his voice is stronger; in other languages the slurring of his speech sometimes renders his words unintelligible. On his recent trip, where the discourses were in Russian and Bulgarian, he had an aide read his texts for him.

“The days, the years, the centuries pass, but not this most holy act, in which Jesus condensed the whole of his Gospel of love,” John Paul said during his homily at the Corpus Christi Mass. The words were poignant, given the toll the passage of time has taken on their speaker.

Corpus Christi —observed by the Vatican on the traditional date of the Thursday after Trinity Sunday —is celebrated with an evening Mass at the basilica of St. John Lateran (the cathedral of Rome), followed by a candlelight procession with the Blessed Sacrament to the ba-silica of St. Mary Major, shorter than a mile away. The traditional procession was halted in 1870, when republican forces seized the Papal States. It was only in 1979 that John Paul revived the custom.

Until 1994, the Holy Father used to walk the route, sometimes carrying the monstrance himself. Since then the monstrance has been placed upon a stand upon a canopied flatbed truck, before which the Holy Father kneels in adoration. This year he knelt for the first half of the procession and then sat in a chair.

Continuous adaptations have to be made by the papal ceremonial officials to respond to the Holy Father's deteriorating health. This year, after arriving at St. Mary Major, John Paul gave the Benediction from the truck itself, eliminating the need for him to descend from the truck.

During the Mass, celebrated by Cardinal Camillo Ruini, the papal vicar for the Diocese of Rome, John Paul remained seated, standing only for the Gospel and kneeling for the Eucharistic prayer. He required the assistance of his aides to stand and move short distances.

In his homily, the Holy Father encouraged new priestly vocations, saying that without them the Eucharist could not animate the Church.

“[The people of God] need the Eucharist,” he said. “In fact, it is the Eucharist that makes the Church missionary. But is this possible without priests, who renew the Eucharist mystery?

“Young Romans! I repeat to you what I said to you at Tor Vergata, during the World Youth Day of 2000: If one of you feels in himself the call of the Lord to give himself totally to him, to love him with an undivided heart, do not allow yourself to be restrained by doubt or by fear,” the Pope continued. “Say with courage your own Yes without reserve, trusting yourself to him who is faithful in all his promises.”

After the homily, during the offertory John Paul earned the applause of the crowd —reported at 20,000 for the procession —when he summoned a young couple with two young children, whom he greeted and kissed.

This year's feast of Corpus Christi came amid unconfirmed reports in both the Italian and international press that the Holy Father is preparing an encyclical on the Eucharist to be released later this year.