By Ya Han Hsu

There have been theories of how covid-19 has first spread among people. Scientists are finding evidence to prove their thoughts, more importantly, people need it to prevent another pandemic.

There are two main theories. First, that the virus had spread because of wild animals contacting humans. Different animals have different kinds of viruses or germs living with them. They may not hurt each other due to millions of years’ evolution, however the microorganisms could be hurtful or even fatal when they are transferred to other species. Some scientists believe that covid-19 was transferred the people from bats. There is also a big market selling live animals in Wuhan. There has been a study which showed that about fifty animals are selled in markets in Wuhan in the eighteen months up to the beginning. It’s a widely accepted theory. It’s similar to the pandemic in 2003 of the Sars virus. “The only difference [with Covid] is that we’ve not found the intermediate species this time,” Prof Robertson says.

The second theory is that the coronavirus leaked out from a science lab in Wuhan. The Wuhan Institute of Virology is under scrutiny, it has been studying coronavirus in bats for over ten years. Scientists have been fighting about the two theories for a long time. A new report disagrees with this theory, but it still couldn’t make some scientists believe. “I see this (new report) as a deliberate effort to marshal all the possible

information in support of what is a perfectly good hypothesis – natural spillover – but (it’s) not balanced and objective,” Prof David Relman, of the US’s Stanford University, told BBC News.

The main reason to find the origin of covid-19 is to prevent the next pandemic from spreading. “What we don’t need right now is for scientists to insist on their favourite explanation in the absence of new, solid data,” says Prof Relman. It’s clear that we need further proof of this, but there is no question that in order to stop the next pandemic we need to be frank and accept our mistakes.

Source: https://www.bbc.com/news/science-environment-57782955