It's known now that Covid is similar to other viruses in its ability to spawn variants. This seems to be a self protective mechanism within the virus to help it survive, and anti-vaxxers are doing their bit to help it along. Omicron has been milder than earlier strains but it also has proved to be more elusive of vaccines. The next one could be more elusive still and not at all milder. For this we have largely to thank the politics of Covid that has convinced millions of people to remain unvaccinated and thereby make themselves laboratories for Covid's next chapter.
https://richmond.com/eedition/richmond/page-b1/page_e6269268-880b-5508-9ba2-aa2c3ced24c9.html
https://richmond.com/eedition/richmond/page-b1/page_e6269268-880b-5508-9ba2-aa2c3ced24c9.html