the football (just needling you ;-))...Omicron is by no means the last possible variant. As the attached article points out, so long as COVID-19 and its variants continue to circulate through the world's population, ANYTHING is possible, and our best defense is to get as many people vaccinated as possible, even if that means re-formulating a new mRNA version, which thankfully we can do in a matter of a few months.
Link: https://www.scmp.com/news/article/3158636/covid-19-why-hopes-omicron-variant-will-prove-less-deadly-may-be-premature?module=perpetual_scroll&pgtype=article&campaign=3158636