Plagues have come out of China for thousands of years, long before humanity had the general ability to engineer bioweapons. The infamous 1918 Spanish Flu actually came out of China.
https://www.kshs.org/kansapedia/flu-epidemic-of-1918/17805
"In 1918 the United States was involved in World War I, but was also dealing with the outbreak of a deadly influenza epidemic. The first cases of the outbreak were recorded in Haskell County, Kansas, and Fort Riley, Kansas, where young men were being hospitalized for severe flu-like symptoms. A local doctor sent a report to the Public Health Service, but no one was sent to investigate the situation. On March 4, 1918, an outbreak appeared at Fort Riley, with as many as 500 soldiers hospitalized within a week. Within a month, however, the number of patients dwindled and it seemed that the flu had passed its course. Many of these soldiers were sent to Europe to help fight in World War I. While in Europe the disease mutated and became deadly. By May many reports of soldiers falling ill were reaching the U.S. It did not take long for the disease to spread from the soldiers to the civilian population of Europe, and then around the world. Few areas remained unaffected, and there were recorded outbreaks in Asia, Africa, Europe, North and South America, as well as the Arctic and remote Pacific Islands. ...
A third and final wave of the epidemic hit in the spring of 1919, and many reported that it was so severe that people could wake up healthy and be dead by nightfall. By the end of spring the number of patients had dropped enough that officials lifted bans from their cities and states and people could resume school and church. Since the disease occurred at the same time as World War I, the epidemic was overshadowed. Although the epidemic only lasted a year, it left a large mark, both in America and worldwide."