STOCKHOLM—The Swedish government plans to introduce a requirement for COVID-19 vaccine passes at indoor events where more than 100 people attend, a step recommended by health officials warning of a rising tide of infections in coming weeks. Infection rates have soared across large swaths of Europe in recent weeks and while Sweden—hard hit at times earlier in the pandemic—has yet to record a similar surge, health agency modelling suggests infections will reach a peak in mid-December. The center-left government was preparing a bill to be put forward to parliament with the aim to having the vaccination passes in effect from Dec. 1, Health Minister Lena Hallengren said. “The spread is increasing in Europe. We haven’t seen it yet in Sweden, but we are not isolated,” she told a news conference. “We need to be able to use vaccination certificates.” Sweden’s health agency said earlier on Wednesday it would reverse a …