SARS-CoV-2, the coronavirus virus responsible for the COVID-19 pandemic, has infected over 9 million people globally and accounted for nearly 500,000 deaths as of June 23. This has led to a global effort whereby researchers have mobilized their labs to better understand the virus. 

However, the exact source of the virus has still not been determined. To understand the origin of the virus causing the COVID-19 pandemic, researchers are screening the environment for all types of coronaviruses, such as those found in bats. These efforts will allow researchers the ability to map out the start of the virus' spread.

To further study coronaviruses in circulation, a group of scientists used samples from 227 bats in the Yunnan Province in southern China. The individual samples were collected between May - October 2019. Researchers next determined the viral strains in the samples and discovered two unique coronaviruses called RmYN01 and RmYN02. 

Upon further examination, it was determined that RmYN02’s DNA sequence was very similar to SARS-CoV-2. However, there were significant differences in regions the virus uses to enter human cells. Looking closer, researchers noted the RmYN02 virus had only one of six critical anchors SARS-CoV-2 uses to enter human cells. These results were surprising considering the overall DNA similarity.

However, the DNA sequence of the RmYN02 virus did reveal unique mutations thought to be only found in SARS-CoV-2. This points researchers to the fact that this is a close relative of SARS-CoV-2. The origin of SARS-CoV-2 is still the subject of much debate, and it will be difficult to prove with certainty how it jumped from its host to humans. In the meantime, scientists are gathering data on other coronaviruses in an effort to prevent future pandemics.