But this doesn't mean it is a patient virus. It has to move fast because its single strand nucleic acid structure is so fragile that it could be easily torn apart by powerful immune systems. It, therefore, causes acute symptoms in the host in order to swiftly leave and jump to another, infecting as many people as possible in a shorter period of time. But at the same time, this strategy sounds alarm for humans to trigger more measures to fight against it.
That's why SARS fizzled out so quickly and completely. Actually, there have been just three cases after 2004, all due to a lab leak. So, what happened to SARS? Where did it go? Scientists believe that the novel coronavirus was hidden in its natural host, the bat. In 2017, in a remote cave in Yunnan Province, virologists identified a single population of horseshoe bats. They harbor virus strains with all the genetic building blocks of the one that jumped to humans in 2003.
Furthermore, the government strictly banned the middle reservoir between bat and human, the civet, after the outbreak, preventing SARS from crossing the line. That could explain why MERS is still haunting humans in Middle East. The middle reservoir, the camel, is a major part of the local life in parts of the region. But, we still have no idea about the middle reservoir of the new coronavirus.
Another ending for an epidemic is what has been called "burn out." That's what happened to the Zika virus epidemic that hit South America between 2015 and 2016. Since Zika cannot infect the same person twice, thanks to the antibodies generated by the immune system, the epidemic reaches a stage where there are too few people left to infect for transmission to be sustained, just like fire flames consuming all the oxygen in a room and extinguishing itself. This is not a desirable scenario because it will cause more infections and deaths.
The last possibility paints a future in which the virus is not contained. The 2009 H1N1 pandemic virus could not be contained in the U.S. and therefore spread all across the world. Since then, this virus has circulated as seasonal flu. Evolution will enable the virus to find a balance between virulence and transmission. Many viruses, like HIV, will take on a milder form, trading off for wider spread. If that is the case, the new coronavirus may return seasonally and join the milder coronavirus strains that infect people as a common cold or pneumonia.