Is this coronavirus different from SARS?
SARS stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS started in China and spread to other countries before ending in 2004. The virus that causes COVID-19 is similar to the one that caused the 2003 SARS outbreak: both are types of coronaviruses. Much is still unknown, but COVID-19 seems to spread faster than the 2003 SARS and also may cause less severe illness.
https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus
I could argue that CoVID-19 is an example of a virus evolving to become more successful as a parasite. An ideal parasite is one that the host doesn't notice, permitting the parasite to feed and reproduce while the host feeds and reproduces.
Pre SARS and MERS coronaviruses had limited access to one of the fastest growing gene pools on the planet. They only infected 10 to 15% of the available population and then only when the population was sufficiently weakened so that they couldn't generate anti-bodies fast enough.
SARS was a breakout period. The mutated SARS coronavirus spread quickly, generated symptoms early, assisting in making it easier to counter and it was fatal to the host in a high percentage of cases. As a virus it was less than successful. As a prototype it was promising.
MERS, I suggest, was a Beta model of the SARS prototype, a randomly generated Beta model at that. It was less successful as a parasite. It was more lethal to the host and spread slower. It too was contained.
CoVID-19 appears to me to be another modified prototype, also randomly generated, but which is successful because, unlike MERS and SARS, it is "doing the other thing". It has a longish, asymptomatic incubation period, it doesn't stress a large percentage of the host population which recovers (especially true of the young which offer a long lived support system to the virus) and it remains contagious long after the host has quelled any symptoms and accommodated the invasion by the new parasite.
Ideally, from the parasite's point of view, in a few years it will be as successful as its rhinovirus relatives and be as ubiquitous as the common cold.
We're not going to get rid of this thing. We, as a herd, will manage it.