In Europe, countries are slamming their doors shut once again, with quarantines and travel bans. In Bangladesh, urban garment workers fleeing an impending lockdown are almost assuredly seeding another coronavirus surge in their impoverished home villages. And in countries like South Korea and Israel that seemed to have largely vanquished the virus, new clusters of disease have proliferated. Chinese health officials announced Monday that they would build a giant quarantine centre with up to 5,000 rooms to hold international travellers. Australia has ordered millions to stay at home. A year and a half since it began racing across the globe with exponential efficiency, the pandemic is on the rise again in vast stretches of the world, driven largely by the new variants, particularly the highly contagious Delta variant first identified in India.