Two new studies provide more evidence that the coronavirus pandemic originated in a Wuhan, China market where live animals were sold, indicating that the virus emerged from the animals sold in the market and that it was not a lab creation.
The research, published online Tuesday by the journal Science, shows that the Huanan Seafood Wholesale Market was likely the early epicenter of the scourge that has now killed nearly 6.4 million people around the world. Scientists conclude that the virus that causes Covid-19, SARS-CoV-2, likely spilled from animals into people two separate times.
According to CNN, the studies were posted online as preprints in February and have now undergone peer review. They were published on Tuesday in the journal Science.
Though both studies took different approaches, they arrived at the same conclusion—the animal market in Wuhan was most likely the epicentre for the Covid.
In the first study, the Chinese scientists and evolutionary biologist Michael Worobey and his colleagues from the University of Arizona collated data by using mapping tools and a social media app to determine the spatial and environmental analysis.
They claimed that the coronavirus was probably present in live animals sold at the market in late 2019 but maintained that the "exact circumstances remain obscure."
“This is an indication that the virus started spreading in people who worked at the market but then started to spread into the local community,” Worobey said in a press conference, reports AP news agency.
The scientists claimed that the earliest COVID-19 cases emanated among market vendors who sold these live animals or people who shopped there. They believe that there were two separate viruses circulating in the animals that infected people.
"All eight COVID-19 cases detected prior to December 20 were from the western side of the market, where mammal species were also sold," the study says.
The second study, however, gives a microscopic analysis to determine when the first coronavirus infection jumped from animals to humans starting with the earliest sample genomes in December 2019 and extending through mid-February 2020.
According to this research, the earliest version of the coronavirus probably had two lineages, which scientists call A and B. It said that these lineages were the result of at least two cross-species transmission events into humans.
The study claims that the first animal-to-human transmission probably came from lineage B and happened around November 18, 2019. They found the lineage B type in people who had a direct connection to the animal market.
They suggest that lineage A was introduced into humans from an animal within weeks or even days of the infection from lineage B. This lineage was found in samples from humans who lived or stayed close to the market.
The scientists concluded by hoping that they can determine exactly what animal may have become first infected and how to reduce the chances of future pandemics.