China has begun a nationwide drive to vaccinate some 50 million front-line workers against the coronavirus before the Lunar New Year travel rush next month, in hopes of avoiding a repeat of last year’s grim holiday season.

Workers in a range of industries will receive their first of two vaccine shots by the middle of this month, with the next shot coming two to four weeks afterward, according to the national plan. The nine prioritized groups include health sector workers, delivery workers, people whose jobs require overseas travel, public servants and utilities employees.

China’s target of vaccinating 50 million people in a month is an ambitious goal, more than the populations of California and Michigan combined. In the United States, where the Trump administration has touted its Operation Warp Speed to fast-track delivery of vaccines, 4.2 million people have received a first dose since distribution began Dec. 14, according to the Centers for Disease Control and Prevention’s Covid Data Tracker.

There’s urgency to complete these vaccinations before the Lunar New Year holiday period — often called the world’s largest annual human migration — which takes place Feb. 11-17. Last year, some 1.5 billion trips were made over the holiday in China, half the normal number, as people sheltered in place against the growing coronavirus outbreak.

After reunion plans were scuttled for many families last year, there is pressure on Chinese authorities to make the country safer for holiday travel this time around. For many in China who work far from home, Lunar New Year is the only time they can gather with their families for celebration and feasting.

“We can’t require people to stay at home and not go out during Lunar New Year,” Shanghai infectious-disease expert Zhang Wenhong was quoted saying in the official People’s Daily on Saturday, even as he said controls may be necessary in higher-risk areas.

Millions in priority groups had received shots as part of an earlier “urgent use” push, before regulators gave the green light to a vaccine from Sinopharm, a state-owned drugmaker, last week. Now, vaccine doses are being rolled out by municipal authorities to all prioritized workers willing to take them, and they should begin to reach some other demographics by next month.

China’s approval of Sinopharm’s vaccine has given confidence to other countries. Egypt said Saturday it had approved Sinopharm’s vaccine for emergency use, while a Pakistani minister said the country would purchase 1.2 million doses from Sinopharm.

However, Sinopharm has also come under criticism for lack of transparency, with scant detail released about its Phase 3 clinical trials. Wu Yonglin, the president of the Sinopharm unit that developed the vaccine, has said that the company will provide detailed data after more observation.

Within China, state media on Monday was awash with reports of the vaccination drive. In the capital city, Beijing, municipal officials reported that 73,537 people received their first vaccine dose in the first two days of the new year.

State broadcaster CCTV showed footage of people standing in line over the weekend at pop-up vaccination sites in Beijing and sitting in socially distanced seats afterward for monitoring for any adverse symptoms. The broadcaster said there were more than 200 vaccination sites in the capital.

Other cities across the country have also announced drives to vaccinate front-line workers over the past two weeks.

Health Times, a state-run newspaper, quoted vaccine expert Tao Lina last month as saying the government planned to vaccinate 50 million people by Lunar New Year, with the first shot by Jan. 15 and second shot by Feb. 5.

Front-line workers eligible for this round of vaccinations include those ages 18 to 59 employed in ports, delivery companies, the transportation industry, health and sanitation, public servants, police and firefighters, utilities, elder care, telecommunications, and people whose work or studies takes them overseas.

Besides the vaccine push, officials have issued some restrictions for the Lunar New Year holiday to try to prevent another surge in coronavirus cases. Several cities limited the size of gatherings to 10 people. Chinese Communist Party members in Beijing have been ordered not to leave the city without permission.

These restrictions are mild compared with last year’s Lunar New Year season, when authorities put swaths of China under lockdown to try to control the rapidly spreading virus. Wuhan, where the virus emerged in late 2019, was sealed off from the rest of the country for more than two months. In many other cities, residents were prevented from leaving their homes without an approved reason.

Alicia Chen in Taipei, Taiwan, and Lyric Li in Beijing contributed to this report.