When American restaurant worker Simon Sunwoo was offered a Chinese-made Covid-19 vaccine in Shanghai this month through his employer he jumped at the chance.
"They wouldn't roll out something that could backfire on them," he said. "I feel like there's too many eyeballs on this for the Chinese to not be relatively sure."
Sunwoo is part of China's expanding effort to get its home-grown vaccines to key workers, including restaurant workers like him, and increasingly to the general public.
China is stepping up its vaccinations as several countries including Brazil, Indonesia and Turkey begin mass vaccination programmes using its vaccines.
Inconsistent data disclosures have raised concern that Chinese vaccines are not subject to the same public scrutiny as U.S. and European ones.
China's domestic effort is intensifying amid a spate of new outbreaks and with a goal of vaccinating nine key groups before the travel-heavy Lunar New Year in February.
China has approved three vaccines for emergency use but only one for the general public. A fourth is only being used by the military.
People aged 60 and over will not get a shot until the safety is confirmed. The same goes for children. In many countries, older people, who are more vulnerable to serious illness from Covid-19, are at the front of the vaccine queue.
Chinese authorities said on Wednesday 15 million vaccine doses had been delivered, enough for just over 1% of the population.
In particular, the campaign has accelerated in the capital, Beijing, according to guidelines published by various authorities. One of the city's biggest districts said this week it had begun vaccinating the general population.
Vaccinated delivery personnel, food workers, educators and medical workers told Reuters of a broad and intensifying effort in what could be the world's largest Covid-19 vaccine campaign.
"If I didn't get the vaccine, I couldn't work. The reality is simple", said a Beijing food delivery worker who was among thousands of couriers vaccinated early this month.
"No one will refuse it," said the worker, declining to give his name because he is not authorised by his company to discuss the vaccinations.
Beijing has not announced phases for the campaign beyond the focus on key workers.
Guidelines vary, though most large cities have begun to invite people from specific groups including medical workers, couriers, customs staff and cleaners.
The city of Beijing has set the tightest deadlines, with plans to vaccinate all key workers before the Lunar New Year, which begins on Feb. 12.
Authorities and those who have received vaccines say cities are not adhering strictly to the designated groups, which allows municipalities and districts to set their own priorities.
Beijing's Chaoyang district said this week it had vaccinated about 164,000 people outside the key groups.
An official from Shanghai's Centers for Disease Control and Prevention said on Tuesday that the city had opened vaccine booking for people beyond key groups, including those who plan to go abroad. Just under 50% of Shanghai's 1.77 million designated key workers had volunteered to get a shot.
"If the country has rolled out this vaccine for everyone, there must be some degree of safety that's guaranteed," said Yi Hongjun, a software researcher at automaker SAIC, who got an initial dose of a vaccine made by Sinovac on Tuesday.
Authorities in several major cities including Beijing and Shanghai say supplies are ample.
A Shanghai school administrator, who declined to be identified, said in December staff were given 48 hours to decide if they would take a vaccine made by Sinopharm, which has yet to pass Phase III trials but has been approved in China for emergency use.
An SAIC worker surnamed Huang who received the vaccine in Shanghai on Tuesday said the process was smooth.
"Once we're vaccinated, we can have peace of mind," she said.