The highly contagious Delta variant is surging in countries around the world, from Indonesia to parts of Europe, leading governments to reimpose restrictions just weeks after they had taken steps to return to ordinary life.
The latest example is Portugal, which on Friday will impose nighttime curfews in Lisbon, Porto and other popular tourism spots, reversing course after it had reopened its economy to prepare for summer travelers.
Scientists believe that the Delta variant may be twice as transmissible as the original strain of the coronavirus. But in countries where high percentages of the population have been vaccinated, the outlook is encouraging, with death tolls and hospitalization numbers remaining low. The vaccines made by Pfizer, Moderna, AstraZeneca and Johnson & Johnson have been found to be effective against the Delta variant.
In Portugal, 56 percent of people have gotten at least one vaccine dose, compared with about 54 percent in the United States, according to Our World In Data.
Portugal’s new curfews are designed to discourage gatherings of younger people at night, said Mariana Vieira da Silva, a cabinet minister. “This is a time to follow the rules, avoid gatherings, avoid parties and seek to contain the numbers,” she said.
Lisbon is now among the areas that will have a curfew from 11 p.m. to 5 a.m., along with Porto, the second-largest city, and Albufeira, a tourism hub in the southern region of the Algarve. The curfew, which comes into force at 11 p.m. on Friday, applies in 19 municipalities ranked as having a “very elevated risk” of Covid-19 and a further 26 with an “elevated risk.”
On Thursday, Portugal reported almost 2,500 new coronavirus cases, the highest daily rise since February, although cases have remained far below their January peak of more 16,000 per day.
In early June, coronavirus cases in the country had dropped so sharply that Britain allowed its residents to visit without having to quarantine on return. But the day after that announcement was made, London jolted Portugal by downgrading it over concerns about the Delta variant.
London’s decisions were especially significant because the British traditionally flock to Portugal as a respite from their often-dreary weather and were even more eager to visit after year of pandemic lockdowns. The switch of travel rules prompted thousands of British tourists in Portugal to pay extra to rebook early return flights to beat a quarantine deadline.
The decision also came less than a week after thousands of English soccer fans had visited Porto, in northern Portugal, to watch the final of the Champions League tournament with no quarantine requirement.
Britain is also facing a surge in Delta cases, although its number of death remains low and hospital occupancy is rising much more slowly than in previous waves of the pandemic. Most of the new cases are among people under 30, and public health officials say that vaccinating younger people is critical to preventing new outbreaks.