evidence: - The updated vaccines should work well against currently circulating variants of COVID-19, including BA.2.86, and continue to be the best way to protect yourself against severe disease. [...] Immune responses to the updated COVID-19 vaccine: People vaccinated with Moderna's updated COVID-19 vaccine, which includes a component that corresponds to the XBB lineage of the Omicron variant, showed a strong immune response against some of the variants that are common now (XBB.1.5, EG.5.1, and FL.1.5.1). They also had an overall boost in COVID-19 immunity that may have waned since their last vaccination or infection. Their antibody responses after vaccination were about 17-times higher against XBB 1.5 and about 10-times higher against BA.2.86 (a rare new variant that CDC is closely monitoring) compared to before vaccination. These data signal that the updated 2023-2024 COVID-19 vaccine likely can provide strong protection against COVID-19 during this fall and winter virus season.