(Bloomberg) -- China has urged local authorities to halt compulsory coronavirus vaccinations as the central government tries to balance the urgency of its inoculation efforts and possible backlash from a hesitant population.

“Some areas are making the vaccination rather simplified, and even mandatory for everyone. This approach must be corrected,” a spokesperson for the National Health Commission said at a Sunday briefing.

The directive appears to be aimed at curbing the heavy-handed tactics of some local authorities to ramp up vaccinations after the government set a target of vaccinating 40% of the population, or some 560 million people, by the end of June. In one example, Wanning, a city in the southern province of Hainan, warned residents could be blacklisted from receiving government benefits or using public transport if they failed to get vaccinated.

Read more: China Pushes Vaccine on Bankers, Colleges to Catch Up With U.S.

China will adhere to the guideline that people get vaccinated voluntarily, according to Wu Liangyou, a senior official at the National Health Commission.

While China has mostly quashed the coronavirus, it is facing hurdles in its vaccination drive as people don’t see the same urgent need to get inoculated as those in countries still battling Covid-19. In order to catch up with western rivals like the U.S., China has been calling on the tens of millions of people who work at state-owned enterprises, and the roughly 90 million Communist Party members, to act as role models in the push. The country has administered 164.5 million doses so far, while the U.S. has delivered 187 million, according to Bloomberg’s Vaccine Tracker.

The vaccine rollout is facing other challenges, including a supply shortage as the acceleration pushes the limits of domestic vaccine makers. Uncertainty is also growing over whether the lower protection rate conferred by Chinese shots, compared to mRNA ones by Pfizer Inc. and Moderna Inc., will hurt the country’s race towards herd immunity.

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