Researchers from the University of Cambridge found three different but closely related types of Corona COVID-19 viruses. All three are divided by types A, B, and C.
Quoting the Daily Mail, strain analysis which shows type A is a virus that spreads to humans from bats through anteater. But this type is actually not the most common case found in China.

He said, type B instead became the cause of the Corona pandemic in China, which is said to have started to spread on Christmas Eve. The results showed this type A is more common in Australia and the United States which have recorded more than 400 thousand cases of the Corona COVID-19 virus.

"Most of the cases in Wuhan are type B while the type C which is derived then emerges and spreads initially through Singapore," said Dr. Peter Forster, one of the researchers.

Two-thirds of the American sample is type A, but the majority of infected patients are from the West Coast not from New York. Meanwhile, Dr. Peter Forster and his team found cases in the UK dominated by type B, with three-quarters of strain testing samples. Switzerland, Germany, France, Belgium and the Netherlands are also dominated by type B.

The other type is type C, descended from type B and spread to Europe via Singapore. Scientists believe the virus officially called SARS-CoV-2 continues to mutate to overcome resistance to the immune system in different populations.

Dr. Forster told MailOnline that type A was originally mutated to type B in China, but type C, 'daughter' B, evolved outside the country. He acknowledged scientists did not understand how to type B 'got rid of' its predecessors and became more common in China.

Type B is found to be comfortable in the immune system of people in Wuhan and doesn't need to mutate to adapt. However, outside of Wuhan and in the bodies of people from different locations, variations mutate much faster.

This shows he adapted to try and survive and overcome resistance among other populations, such as Westerners. Data analysis shows that the original virus might have been circulating in China since September.