Covid is a SAR virus which Thailand went through the SARS outbreak back in the mid 2000's. If you recall they were taking everyones temperature when entering Thailand at the time.
It's called COVID 19 as an abbreviation for 2019 novel coronavirus, not that there were 18 different variants before it.
The 2002–2004 outbreak of SARS, caused by severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), infected over 8,000 people from 30 countries and territories, and resulted in at least 774 deaths worldwide.[1]
The outbreak was first identified in Foshan, Guangdong, China, in November 2002.[2] The World Health Organization (WHO) was notified of the outbreak in February 2003, and issued a global alert in March 2003. Initially, the cause of the outbreak was unknown, and some media outlets reported that an influenza virus was a potential culprit.[3] The major part of the outbreak lasted about 8 months, and the World Health Organization declared SARS contained on 5 July 2003. However, several SARS cases were reported until May 2004.[4]
In late December 2019, SARS-CoV-2, a coronavirus in the same genus as the one that caused SARS, was discovered in Wuhan, Hubei, China. It spread to other areas of Asia, and then worldwide in early 2020. This strain causes COVID-19, which has caused the COVID-19 pandemic.[5][6]