30 December 2022. When a country of 1.4 billion people suddenly ended its zero-Covid policy after nearly 3 years, there was little doubt what would happen. Poor immunisation levels and little natural immunity meant an explosion of cases – just as China is about to lift restrictions on its citizens travelling abroad. So now, some countries – wary of an influx of cases – are imposing Covid testing, and possible quarantine. Covid wave hitting China is not due to some radical new variant, but Omicron in its different forms.