Pope Leo XIV is holding a mass in Santa Cruz de Succhabamba in northern Peru on Saturday as he continues his tour of South America, drawing huge crowds as people seek to catch a glimpse of the 71-year-old pontiff.

ADVERTISEMENT

ADVERTISEMENT

After travelling by helicopter from Chiclayo air base to Santa Cruz de Succhabamba, Leo flies back for a prayer meeting with the Catholic community at the shrine of Saint Toribio de Mogrovejo in the evening.

The pope returned to his beloved former hometown of Chiclayo on Friday.

The Chicago-born pontiff, who previously worked as a missionary and then bishop in Peru and holds Peruvian citizenship, presided over an open-air mass for around 500,000 people in the city.

"What a joy it is to return to Chiclayo!" Leo said. "Thank you for your affection, support and prayers, especially for my health during this time of trial which, with God's help, I am overcoming."

But the huge crowds turning out to see the pope have prompted heightened fears among health authorities in Latin America, which has seen a surge in measles cases this year.

From January to the end of October, 57,666 confirmed cases were recorded in 17 countries and territories in the Americas, almost five times more than in the same period the previous year. At least 81 deaths have been reported.

Ahead of Leo's visit, the Pan American Health Organization (PAHO) considered the public health risk of measles "very high" in the context of the expected religious mass gatherings.

The concern is mainly linked to low vaccination rates in some countries, particularly Argentina and Peru.

"We’re seeing children not going to school, children being hospitalized," Daniel Salas Peraza, the head of immunization at PAHO, said. "It’s a very complex situation."

Measles

Measles is a highly contagious airborne disease caused by a virus. It can lead to severe complications and is potentially fatal.

The disease infects the respiratory tract and then spreads throughout the body. It can cause symptoms including a high fever, a cough, a runny nose and a rash.

An effective and relatively cheap vaccine is available.

According to the World Health Organisation, "children should receive two doses of the vaccine to ensure they are immune."

"The first dose is usually given at nine months of age in countries where measles is common and 12–15 months in other countries. A second dose should be given later in childhood, usually at 15–18 months," the agency says.

To stop the disease from spreading in a community and to protect infants and others who are unable to get the vaccine, at least 95% of the population must be fully vaccinated.

According to WHO data for 2025, only Uruguay had reached this threshold. In Peru, coverage stood at 90% for the first dose and 82% for the second. In Argentina, the figures fell to 84% and 55% respectively.

Peru has recorded almost 3,000 cases in 2026, the fourth highest number in the Americas after Guatemala, Mexico and the United States.

In the five cities included in the Pope's itinerary - Lima, Chiclayo, Cajamarca, Cusco and Pucallpa - 170 infections have been detected so far this year.

In the run-up to the visit, Peruvian authorities stepped up vaccination campaigns, focusing especially on areas with higher transmission rates.

Initiatives have also included bringing forward vaccination for children between six and eleven months of age and campaigns targeting people up to 29 years old. By the end of September, 1.2 million doses had been administered since the push began in April, while more than two million additional doses were available.

The situation is also tricky in Argentina, where at the end of October, authorities issued a warning about the health risks linked to the Pope's visit. Up to four million people were expected in Buenos Aires province.

Experts are also worried about government cuts to health spending, which have scaled back the structures responsible for planning, funding and monitoring immunisation campaigns.

For its part, Uruguay has launched a period of enhanced epidemiological surveillance across the nation, which will continue until 29 November, weeks after the pope's departure.

Authorities have also intensified appeals to the public to complete their vaccination courses. The aim is to detect any new infections quickly and limit the spread of the virus after the large gatherings.