In the early days of 2020, as science looked for answers to a mysterious viral outbreak in central China, a prominent Chinese virologist stepped forward to share critical data with the world.

Zhang Yongzhen’s disclosure of the genome of the virus that causes Covid-19 was a crucial step in the race to combat the pandemic, helping researchers globally to identify the pathogen and create vaccines to counter it.

He was lauded for his integrity by the scientific community, but in the years since, people who know Zhang say he has faced a series of unprecedented roadblocks in his career in China – with yet another barrier placed in front of his research over the past week.

On Sunday and Monday, Zhang, 59, slept overnight in protest outside his lab at the Shanghai Public Health Clinical Center after administrators closed the facility abruptly for renovations, according to accounts posted on his Weibo social media page.

A post on his page early Wednesday said a “tentative agreement” had been reached for Zhang’s team to resume their scientific work at the lab, some of which is related to tracing the origins of Covid-19.

The ordeal is just the latest hindrance to Zhang’s research since 2020, according to a colleague who has been in contact with the Chinese scientist in recent years.

An account by Zhang’s research students posted online also laid out a litany of challenges faced by the scientist since the formal transfer of his official employment to the Shanghai center in 2020, when his 19-year tenure at the Chinese Center for Disease Control and Prevention also ended.

“That a top scientist in his field, a person who has made contributions to the country and mankind should have fallen to this point – is really sad and chilling,” the post read.

In a statement Monday, the Shanghai Public Health Clinical Center said it had closed some labs for renovation due to safety concerns and claimed it had provided additional office and experimental spaces for Zhang and his team.

The “institute always respects … and supports scientific researchers and students in carrying out normal research work,” the statement said.

Images posted on social media this week appeared to show Zhang wrapped in blankets and sleeping on the doorstep of the lab building as security guards hovered over him.

More than a dozen students’ research had been impacted by the lab closure, he said, adding it was “inconvenient” to say more at that time.

The earlier post by Zhang’s students said the two days originally allocated by the center for them to move their scientific work was insufficient. Their lab had been renovated as recently as 2020 and a second lab hadn’t been in use since the pandemic, they added.

Neither Zhang nor the online post detailing the circumstances leading to his protest connected the lab closure to his sharing of the coronavirus genome sequence in 2020.

‘Broken machine’

Zhang became the first scientist to share Covid-19’s genomic sequence on January 11, 2020 as the World Health Organization waited for China to provide the data following its announcement nearly two weeks earlier of a viral outbreak in the central city of Wuhan.

He was hailed internationally for his work and named by Nature as one of 10 people who helped shape science in 2020.

In an interview with the journal that year, Zhang reflected on his global recognition.

“They say, ‘January 11 was a turning point for understanding that this is serious. It was a turning point for China. It was a turning point for the world,’” he said.

But in China, Zhang faced challenges to his work that stemmed from that moment, according to his long-time collaborator Edward Holmes, a University of Sydney professor who published the genome with Zhang’s permission on an international data sharing website.

Following the release of the data, Zhang’s lab had limitations placed on it, which barred it from isolating the Covid virus, Holmes said.

It’s unclear if this move was separate from a Chinese government “rectification” order received by Zhang’s team that reports at the time said resulted in the temporary closure of the lab a day after the sequence release. Zhang told Nature in 2020 that the order merely required his lab to update its biosafety protocols after moving equipment during construction work.

Zhang, a scientist with China’s CDC since 2001, was also forced out of the agency in September 2020, according to a person familiar with the situation.

These changes for Zhang came as China – already known for top-down control on the academic sector – tightened oversight of scientific information related to the virus. That included imposing restrictions by April 2020 on the publication of academic research on the origins of the novel coronavirus.

Beijing has repeatedly defended its scientific transparency and data sharing related to the outbreak.

“In the old days, pre-Covid … he was like a machine and now the machine is broken. He’s just been slowly crushed by this.”

‘No regrets’

In the months after he shared the Covid-19 sequence, Zhang’s employment was transferred to the Shanghai Public Health Center, where he had held a five-year cooperation agreement and part-time professorship since 2018. It’s unclear if this move was already in the works prior to January 2020.

Since then, he has continued to publish in journals such as Cell and Nature Microbiology on the presence of viruses in animals and nature in China and received at least two international awards.

The most recent of his international publications in March looked at coronavirus variants in Shanghai in the initial months of the Covid-19 outbreak, and Zhang’s team continues to work on research related to the virus and its emergence.

Ongoing research includes a National Natural Science Foundation of China project at the laboratory, the post said.

In a Weibo post on January 11 marking the fourth anniversary of his Covid disclosure, Zhang appeared to allude to the challenges he has faced in the years since.

“Four years ago this morning, on behalf of the research team, we insisted on putting life first and made the right choice,” Zhang wrote.

“Despite going through continuous ups and downs, experiencing the warmth and cold of human emotion, and the harshness of the world, we have no regrets.”

But recent years have taken a steep toll on Zhang, according to Holmes.

“He’s not the same in terms of his productivity, he’s completely different – not the same person at all. It’s just been extraordinary to watch and extraordinary that it’s come to this,” he said.

Holmes, who had limited email contact with Zhang during his protest this week, said the Chinese virologist had told him he recently failed in his pursuit of a legal case against the Shanghai center for its handling of his contract.

“(All this has) gone on for a long time … but I hadn’t realized how bad it had got,” Holmes said.