The COVID-19 vaccines give strong protection against severe disease and death from all currently circulating variants of the virus that causes COVID, including the Delta and Omicron variants.
The Omicron variant has replaced the Delta variant as the dominant strain of COVID-19 in Hawai‘i. While vaccines reduce a person’s rise of getting the virus, Omicron is so contagious that breakthrough infections do occur. Even then, the vaccines dramatically reduce hospitalization and death.
https://health.ucdavis.edu/coronavirus/covid-19-information/omicron-variant (UC Davis)