Few places can rival Macau when it comes to fighting the coronavirus. Having got the Covid-19 pandemic largely under control as early as last summer, the gaming hub has justifiably become the envy of many places that are still struggling with a fresh wave of new cases. Alas, there is no room for complacency. Macau’s latest outbreak of the more infectious Delta variant in a local family is a cautionary tale for neighbouring Hong Kong, which is also on high alert after a 13-year-old pupil who shared a hotel room with the Macau patient during a school trip to the mainland is now under quarantine with her family here. Separately, Hong Kong officials are investigating another local case. The need to stay vigilant has never been higher. At stake is not just a possible end to Hong Kong’s 57-day streak of zero local infections. While there has been no evidence yet to prove the Delta variant in Macau has spread, the compulsory quarantine for the family related to the latest outbreak is a prudent and necessary step. Meanwhile, authorities must work harder to ascertain whether the positive test result involving an asymptomatic construction worker is a case of undetected infection from an earlier outbreak. As the authorities have warned, the existence of hidden transmission chains cannot be ruled out at this stage. Macau leader sorry over chaos of universal Covid-19 tests Outshone by Macau’s antivirus efforts, the Hong Kong government is under pressure to control the spread here, as failure would mean further delays in reopening the border with mainland China. But the outbreaks of variant strains in the region have also highlighted the risks involved. As medical experts have rightly cautioned, the threats arising from cross-border travel must not be ignored. Even a role model such as Macau cannot afford to be ill-prepared. Macau Chief Executive Ho Iat-seng admitted that his government was struggling to cope with the situation. The chaos and panic arising from the emergency response, including mass testing for the population of 640,000, is a lesson for authorities around the world. Whether the same measures can be adopted here in the event of a similar outbreak is questionable. A voluntary mass screening last September was shunned by three-quarters of the population. Currently, imported infections are contained by tight quarantine measures, while local cases are tackled by premise-based lockdowns and tests as well as isolation of patients’ close contacts. But still, there are sporadic outbreaks. The suggestion that zero infections cannot be a realistic long-term goal is worthy of deeper reflection. Ultimately, vaccination is still the key to bring life back to normal. Meanwhile, officials should re-examine the restrictions in place to further strengthen safeguards.