The Zhuhai Special Economic Zone in Guangdong province has become the first city on the Chinese mainland in which more than 80 percent of the population has been vaccinated against COVID-19.

As of Tuesday at noon, about 1.42 million people between 18 and 59 years old have been vaccinated, playing a role in building a protective screen against the pandemic in the city, which borders the Macao Special Administrative Region, the local health authority said.

Zhuhai, a front-line port city to prevent the importation of the coronavirus into the mainland, has now increased its vaccination capacity to more than 100,000 doses a day from 5,700 daily doses previously after it started a mass vaccination effort on March 21.

The city has now put more than 450 vaccination units into service, compared with just 64 about a month ago.

"Now the city has 25 fixed vaccination centers, plus 24 mobile centers near the city’s busy shopping malls and related destinations," authorities said. The mobile centers include 16 on specially adapted public buses.

Meanwhile, medical teams are being sent to local university campuses, major companies and rural areas to offer vaccination services to local residents, the health authority said.

A special task force headed by the mayor has been established to focus on the promotion of the vaccination work in the city.

Earlier this month, Zhuhai was listed as one of the five key cities to conduct mass vaccinations in Guangdong. The other four cities include Guangzhou, Shenzhen, Dongguan and Foshan — all major exit-entry cities in the prosperous Pearl River Delta that have advanced railway and highway networks linking them to major cities and regions on the mainland.