Last weekend Portugal placed first in the world for its COVID-19 vaccination rate, with 85 percent of its population fully vaccinated. Its campaign has been a sensational success — and even more incredible given how poorly the country was dealing with the spread of the virus at the start of 2021.

The Portuguese government, currently led by Socialist Party prime minister António Costa, has had a mercurial approach to the coronavirus. An early call for isolation and eventual lockdown in 2020 resulted in lower infection and mortality rates than many of its European neighbors. But following an easing of restrictions in the summer, Costa found it hard to reimpose strict measures for the winter holidays.

As the flux of people socializing and moving around the country increased, so, too, did the case numbers. The situation was significantly worsened by the arrival of the delta variant at a time when health systems were particularly strained. By February 2021, Portugal had the highest COVID-19 infection and death rates in the world.