As the fight against the COVID-19 pandemic in China is gaining momentum with more than 1.3 billion doses of vaccines administered so far nationwide, news about the detection of three new locally transmitted novel coronavirus infections in Ruili, Yunnan province, on Monday is especially disturbing.

This is because it is the fourth time the city, which borders Myanmar, has reported cases within a year. The previous cluster of infections in late March, which forced the city to impose lockdowns and launch a massive testing campaign, led to the sacking of its Party chief due to dereliction of duty that "seriously undermined epidemic control work" in the country and the province.

Thanks to the experience accumulated during its handling of the previous outbreaks, Ruili has already responded in a timely manner to the emergency this time, imposing entry and exit restrictions and launching all-inclusive nucleic acid testing. This serves to give the public more confidence that the city will get the situation under control in the not too distant future, as admittedly it has on the previous occasions.

Yes, Ruili is special in that it has a long border with Myanmar and a large migrant population from that country where the COVID-19 pandemic is still wreaking havoc. This time one of the infected patients, just like in previous cases, is a Myanmar national.

But while more information is yet to emerge for the authorities to find out all that is behind the latest outbreak, there is no doubt much higher requirements must be set for the city in its prevention and control protocols, not only in detection, quarantine and treatment, but also in tracing, testing and vaccination.

The sense of urgency is accentuated by the fact that the city had been presumed to be safe after it already tested all its residents and asked everyone to be vaccinated after the outbreak three months ago.

This time Ruili must make doubly sure that it has done all it can to plug all the existing loopholes — for example by closing the crossings to Myanmar until the pandemic situation completely stabilizes across the border — so as to ensure it wins the fight against the virus.

On the very front line against imported cases, Ruili bears a major responsibility not to repeat the misfortune again in the days to come. It must have the courage to say to itself that there will be no more, given the huge economic loss and large disruptions to social life that the city, as well as the rest of the country, will have to suffer should the firewall against the coronavirus be breached.