Bangladesh, Nov. 29 -- The overcast, drizzly skies match the somber mood at the Tshwane University of Technology, a hot spot in South Africa's latest surge of COVID-19 cases, apparently driven by the new omicron variant that is leading countries around the world to impose new restrictions.

After several students tested positive, the university postponed some exams, and officials in the larger metropolitan area of Tshwane, which includes the capital of Pretoria, are pushing vaccinations, especially among younger adults who have been slow to get the shots.

At TUT, as the university is known, few students wanted to speak about the new variant that has cast a pall. Many were not vaccinated - only 22% of 18- to 34-year-olds in South Africa a...