Anyang, a city with a population of 5 million in Henan province, was locked down on Monday. It is the third city to hit the pause button in China over the past month, highlighting the challenge the country still faces in its fight against the novel coronavirus.

There were 110 locally transmitted infections reported in the Chinese mainland on Monday, among which 87 were in Henan, 13 in Shaanxi province and 10 in Tianjin. As of Tuesday noon, Tianjin has reported a total of 97 cases since last weekend.

It is not only the numbers themselves that have prompted the local authorities to make the decisions to lock down these cities but more importantly they have been spurred to do so by the potential of the virus to inflict damage on public health, social stability and the economy should the infections spread.

Arguably the only major country to have adopted a zero-tolerance approach in its fight against the virus, China has always acted quickly so it can seize the initiative — which many countries have surrendered long ago. Thanks to its perseverance and inputs into its zero-case strategy, particularly the over 80 percent vaccination rate, the last death caused by the virus on the mainland dates back to January last year.

As such, although the number of infections are low, the lockdowns are not unreasonable. Particularly since the 2022 Beijing Winter Olympic Games will soon open and the Lunar New Year holiday is just three weeks away and this is a peak travel period.

Notably, the cases in Tianjin and Anyang are the highly infectious Omicron variant of the virus, and according to the Tianjin epidemic prevention and control department, the variant might have been transmitting in the port city with a population of 14 million for at least two weeks before it was identified last weekend, with the origin of the infections remaining unknown. That the cases in Anyang can be traced back to Tianjin means the cross-region transmission of the Omicron variant is already a reality. Neighboring Beijing and Hebei provinces must be on the highest alert.

A national transport hub in Central China, Henan has every reason to take strict measures to cut the transmission chains of the virus in its jurisdiction as is being done in the provincial capital Zhengzhou and neighboring Xuchang. Without such efforts, Henan could easily become a steppingstone for the virus to extend its transmission chains nationwide, which would undo what the country has achieved over the past two years.

The tranquility of people's lives in the rest of the country is partly attributable to those bravely fighting on the front line in the affected regions. But the battle against the virus is a people's war, and people are either already engaged in the fight in some capacity or in reserve.

The whole country must raise its vigilance again and overcome any sluggishness or complacency, as now is another critical phase in the seesaw battle with the virus that treats all encounters as its first.