China has always upheld principles of openness and transparency in studying the origins of the novel coronavirus and has been cooperating efficiently with global researchers and sharing relevant data continuously, according to an article published by a group of Chinese scientists on Thursday.

They said that there is no definitive conclusion regarding the origins of the virus and tracking them down will take tremendous efforts. They called for maintaining a scientific and logical attitude in future research.

The article is jointly written by scientists from several institutions, including the Chinese Center for Disease Control and Prevention, Chinese Academy of Sciences, Chinese Academy of Medical Sciences, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, and Peking University's School of Life Sciences.

It was published on China CDC Weekly, a national public health bulletin and an academic platform established by the CDC.

"On the issue of SARS-CoV-2 origin, all the studies and the related conclusions should be based on science," they said. "The Chinese scientists have always maintained an open, transparent, and responsible attitude and practice, and worked together with scientists from all over the world on origin tracing and contributed a lot of scientific references."

During the initial phase of the COVID-19 epidemic hitting Wuhan, Hubei province, the hardest from late 2019 to early 2020, a number of cases were found to be linked to the Hunan seafood market in the city. As a result, researchers from the China CDC and local disease control workers were dispatched to collect and analyze environmental and animal samples.

"These results were timely and continuously informed to the public through official media. After the surveillance work in the field, the data were further analyzed and during the WHO-convened Global Study of Origins of SARS-CoV-2: China Part from July 2020 to February 2021, the results were reported to WHO experts and comprehensively discussed by a joint expert team of WHO and China," they added.

At the same time, Chinese researchers have summarized their analyses linked to the seafood market and released their findings to the public in preprint study. Raw data related to the study were also deposited to the Global Initiative on Sharing All influenza Data (GISAID), an international database.

"The data were not removed or deleted since the deposit. In accordance with the usual practice of publication, and by agreement with the journal and GISAID, the data would be released simultaneously with the formal publication, but the link to access the data for journal review has always existed," they said.

However, they stressed that all these data only showed that the market has acted as "an early amplifier during the pandemic due to the high number of consumers every day, causing many initially identified infection clusters."

"The origin of the virus involving animal-to-human transmission cannot be determined based on the current data," they said.

They said that hypotheses and conclusions presented in the report released by the WHO in March 2021 are scientific and objective.

They added that tracing origins of the virus is a scientific issue that requires scientific evidence and logical inference. Determining origins of the novel coronavirus may still be a long way off.