CRP and infection: Moreover, the serum levels of ALT, AST, and CRP in both the Omicron-FS and Omicron-only groups were moderately increased compared with those in the FS-only group, but we did not deem these three elevated parameters to be the potential drivers for FSs associated with Omicron infection because no difference in these three parameters was found between the Omicron-FS and Omicron-only groups.