More than half a million Hong Kong people live in other parts of China, so resuming normal cross-boundary travel has to be a priority for authorities. The first stage of that process, allowing citizens from Guangdong province and Macau to return without 14 days of Covid-19 quarantine, has been in place since November 23. Epidemic control measures on the mainland have ensured negligible infection numbers and outbreaks that do occur are quickly snuffed out. Widening the scheme to the rest of the country as the government is considering makes sense, and there is also merit in Chief Executive Carrie Lam Cheng Yuet-ngor’s suggestion that for the sake of local business and tourism, it could be enlarged to include mainlanders. But what makes sense on paper is not necessarily practical. Although 5,000 Hong Kong people can come to the city each day through two immigration entry points under the Return2HK scheme, the take-up has been a fraction of that; during the first two months, the daily average was just 560. Meeting the specified conditions is not difficult, requiring only proof of a negative Covid-19 test, making an online booking and getting into the quota. What makes the idea unappealing to many is that on return to the mainland or Macau, there is a requirement to undergo 14 days of quarantine at a designated location. Hong Kong’s travel bubble hopes ride on pandemic control, vaccination rate Hong Kong has dramatically brought daily infection numbers down since the peak of the fourth wave through strict mandatory testing and tracing. But even single-digit figures, the majority of cases being imported, is considered too lax by mainland standards. Vaccination levels of just 7 per cent are also low, furthering concerns about Hong Kong’s resolve to stamp out the virus. There is no possibility of the quarantine-on-return rule being amended until the city has demonstrated that it has the coronavirus firmly under control. Businesspeople or tourists may not be willing to invest the time and perhaps money to be quarantined after visiting Hong Kong. Hongkongers have not been wildly enthusiastic about the idea, either, although those with urgent needs can benefit. For citizens, the scheme should be enlarged. But if cross-boundary travel is to resume as before, the city has to do a better job to attain the goal of zero infections.