https://www.siliconvalley.com/2022/01/25/why-dont-we-have-covid-19-vaccines-for-new-variants/

Every fall, pharmacies fill with fresh influenza vaccines, tailored for nature’s latest version of that miserable bug after it emerges half a world away. As the COVID-19 vaccines’ protection wanes against newer variants of the coronavirus, like omicron, shouldn’t those shots be reformulated as well?

“It’s time for an updated version,” Dr. Michael Lin, an associate professor of neurobiology and bioengineering at Stanford University, said on Twitter this past week after a fourth dose of Pfizer’s COVID-19 vaccine delivered only partial protection against infection from the virus, according to a study in Israel. “They said it would be easy so just do it already.”