CHMP5 and infection: While it is perhaps unsurprising that COVID-19 vaccines based on ancestral SARS-CoV-2 sequences will not generate sterilizing immunity against Omicron strains that have evolved to evade host immune responses (4, 40–44), various lines of evidence suggest that “hybrid” immunity resulting from vaccination plus infection nevertheless provides enhanced protection against SARS-CoV-2 variants (5, 45), due in part to maturation of Spike-specific antibodies (46–48) and expansion of antiviral T cells (49–54).