TAIPEI, Taiwan (JTA) — Rabbi Martha Bergadine had been in a sort of limbo since January, when she decided to leave Hong Kong for the first time in two years to visit her son at university in the United States. At first, the timing seemed right: Hong Kong — with a “dynamic COVID-19 policy” that had helped keep the spread of the virus under control — boasted one of the world’s lowest infection and death rates: For most of December, the seven-day new case average was lower than 10 per day. Enter the Omicron variant. In December, as COVID-19 cases...