Northern Ireland’s deputy first minister, Michelle O’Neill, has coronavirus and is self-isolating, underlining the region’s high infection rate. “I have contracted Covid-19,” the Sinn Féin vice-president tweeted on Tuesday. “I am thankful to have had two doses of the vaccine. I’ll remain in self-isolation, and hope to return to my public duties next week.” Well-wishers on Twitter wished her a quick recovery. The 44-year-old did not disclose if she was experiencing symptoms. Declan Kearney, her Sinn Féin colleague and executive office minister, will fill in until she returns, O’Neill said. A meeting of the Stormont executive to discuss easing restrictions that was scheduled for Wednesday has been postponed. Northern Ireland has the second-highest case rate in the UK, at 615.3 per 100,000 people. Vaccine uptake in Northern Ireland is marginally lower than in the rest of the UK, with 77.4% of people aged 16 and over having had two doses compared with 78.3% in England, 80.9% in Scotland and 83.6% in Wales. The region’s high infection and death rates have puzzled experts. Mark Tully, a professor of public health at Ulster University, suggested a possible link to Northern Ireland’s higher levels of chronic disease and social deprivation. Limits on capacity due to Covid prevention measures have worsened delays at hospitals, with 400 emergency patients recently having to wait more than 12 hours to be admitted. Authorities reported six coronavirus-related deaths on Monday, raising the total since the pandemic began to 2,358. Another 1,259 infections were reported on Monday, up from 1,225 on Sunday, bringing the total close to 200,000. Business leaders and the Democratic Unionist party (DUP) have urged the power-sharing executive at Stormont to end remaining restrictions, such as the closure of nightclubs. Sinn Féin has argued for more caution. The Republic of Ireland government on Tuesday will set out a timetable for lifting most remaining restrictions in the country. Eamon Ryan, the leader of the Green party which is part of the ruling coalition in Ireland, said “personal responsibility” would replace restrictions that will be unwound in the next few months.