LONDON - Though it is known that SARS-CoV-2, the virus responsible for the COVID-19 pandemic, originated from animals, its exact source and intermediate host remain unclear, an article has said.

The article published Tuesday on News Medical, an open-access medical and life science hub, explained how the virus reached humans, based on observations of previous coronavirus outbreaks.

Citing research findings by scientists at the University of Glasgow Centre for Virus Research in Britain and the South China Agricultural University in Guangzhou, China, the article shed light on how the virus may have reached humans from animals.

Humans are now the dominant SARS-CoV-2 host species, it warned, adding that there is therefore a danger of the virus jumping from humans to other animal species, called reverse zoonosis, as is suspected for white-tailed deer in the United States.

"Humanity must work together beyond country borders to amplify surveillance for coronaviruses at the human-animal interface to minimize the threat of both established and evolving variants evading vaccines and to stop future spillover events," researchers urged in the article.