China is now carrying out millions of COVID-19 vaccinations each day, mostly in a bid to achieve ring immunity, limiting the risk of any possible spread of the virus by administering the vaccine to people who are most likely to be infected — such as those working in the cold chain, healthcare, public transport and service sectors. More than 136 million doses have already been administered, according to the National Health Commission.

Yet that figure is still a far cry from the level necessary to prevent the further spread of the virus, and achieving the herd immunity target of vaccinating more than 60 percent of the population by the end of the year.

It also falls behind those in some other countries such as Israel and the United Kingdom, which already have more than half of their population vaccinated for COVID-19.

The latest outbreak of COVID-19 cases in Ruili, Yunnan province, once again points to the urgency of building herd immunity, or at least herd resistance, the level of immunity in the population that reduces infection rates, through a massive vaccination drive.

This is especially important given that the rest of the world is slowly reopening after more than a year of lockdowns due to the pandemic, and as vaccination rates rise there will be more cross-border travel.

Ruili, which borders Myanmar, reported 15 new locally transmitted COVID-19 cases and five new asymptomatic cases on Sunday, all detected during a citywide nucleic acid testing. In total, it now has 51 confirmed cases, and 56 asymptomatic cases, according to the provincial health commission on Monday.

Though China has basically eradicated local COVID-19 transmissions, the fact that it is the second time in seven months that the border city has been forced to lock down in response to a fresh outbreak suggests the successful methods in the fight against the pandemic — early detection, early testing, early quarantine and early treatment — could be tested in the face of infections imported from outside the country. Of the new patients reported in Ruili, many were identified as Myanmar citizens.

Thus if the country plans to reopen its borders while still keeping its economic activities and social life on the normal track, it must build a firewall against the virus as soon as possible by vaccinating its general population.

Ruili is already carrying out an aggressive campaign to vaccinate all its 300,000 residents within five days, which began on Friday.

Vaccines have proved safe and effective against COVID-19 infections. With four vaccines already approved for general use and a daily output of more than 5 million doses, China is fully capable of achieving herd immunity. How soon that day will arrive depends on how quickly vaccine doses can be distributed and how willing each one of us is to have a jab.