On Wednesday, state-owned vaccine maker Sinopharm announced that nearly 1 million people in China have received its COVID-19 vaccine candidates as part of the emergency use vaccination program China launched in July. Under the scheme, China is injecting frontline medical workers, government employees, customs laborers, overseas contractors, and other groups it deems essential or at high risk of contracting the virus before publishing safety data or concluding its final-stage testing.

Sinopharm is currently testing two separate COVID-19 candidates in phase III trials featuring tens of thousands of volunteers in countries like Egypt, Bahrain, and the United Arab Emirates. (The UAE also announced its own emergency program in September using Sinopharm’s vaccines).

The 1 million figure suggests that Sinopharm’s inoculation program has rapidly expanded in recent weeks. The company announced in September that 350,000 people had received doses of its candidates at that point.

The data also suggests that China has a fairly broad definition of which populations merit “emergency-use” immunizations.

Sinopharm chairman Liu Jingzhen said on Wednesday that 100,000 people had been given the vaccine during the China International Import Expo, a trade fair that just concluded in Shanghai. Earlier this year, Sinopharm briefly opened an online portal that allowed students traveling overseas to apply to be injected with its vaccines. Over 90,000 students applied to take the shots before Sinopharm pulled down the portal days after putting it up.

Two other Chinese vaccine makers, Sinovac and CanSino, are also distributing vaccines via China’s emergency use program.

Experts believe that distributing vaccines before the conclusion of testing or prior to meeting pre-determined safety benchmarks is risky given that reviewing the data is important to determining whether a potential vaccine candidate is effective or has health side effects.

Such safety concerns are why Pfizer and Moderna have waited for more data before requesting emergency authorization in the U.S. even though preliminary phase III trial results show both companies’ doses are highly effective.

Pfizer, which is partnering with Germany’s BioNTech and China’s Fosun Pharma, now has the safety data it needs and is expected to file paperwork to the U.S.’s Food and Drug Administration for emergency use approval on Friday. Obtaining that permission would allow Pfizer to distribute its vaccine to high-risk populations, like healthcare workers.

Moderna is expected to file for similar emergency use authorization “soon,” U.S. Health and Human Services Secretary Alex Azar said at a press briefing on Thursday. U.S. Vice President Mike Pence, who also spoke at the press conference, said that vulnerable populations could be just “weeks away” from receiving vaccines.

Dr. Anthony Fauci, director of the U.S.’s National Institute of Allergy and Infectious Diseases, has criticized China’s deployment of the emergency use program without thorough, transparent testing.

“Claims of having a vaccine ready to distribute before you do testing, I think, is problematic at best,” Fauci said at a congressional hearing in July.

Chinese officials have defended the program, saying that all vaccine recipients participate in the program voluntarily and understand the risks involved in taking an unproven vaccine.

“China’s vaccine emergency use authorization process is strictly governed and conducted in accordance with related laws and regulations,” Zheng Zhongwei, head of China’s COVID-19 vaccine development task force, told Chinese media in October. “We have not received reports of any recipient of the Chinese COVID-19 vaccine approved for emergency use as having severe adverse effects.”