a major impact on the number of hospitalizations. reporter: doctors are also hopeful about new covid boosters, expected to be authorized soon as the country sees an uptick in cases. eg.5, also known as eras, is now the dominant strain, but is closely related to previous mutations. so unless another variant pops up experts predict new boosters should be a good match. we should start to think about the updated covid vaccine almost like our annual flu vaccine. now is the time to fill up that immunologic gas tank to protect us as we move into the winter. reporter: doctors also expect a good match from this year s flu vaccine. americans of all ages being encouraged to roll up their sleeves for what may be new tools against a tripledemic. kristen dahlgren, nbc news, new york. and officials in florida are warning about a rare flesh-eating bacteria that has killed five people in the state this year. it s called vibrio and