September 2023, CDC’s recommended the updated 2023–2024 booster COVID Vaccine (monovalent XBB.1.5). MMWR study shows only 18% of high risk (immunocompromised) recv'd it. Vax was 38% effective at preventing COVID hospitalization https://t.co/vf5jkMkPwj https://t.co/c55SuIuaDb