COVID vaccines protect against serious illness, hospitalization, or death from COVID. Anyone age 6 months and older is eligible to be vaccinated. The COVID virus continues to change, which mean vaccine recommendations may change to respond to the virus. This is why there's an updated 2023-2024 vaccine, and CDC anticipates there will be an updated COVID vaccine for 2024-2025, similar to what happens with the annual flu shot.
The CDC recommends that everyone who is eligible get vaccinated, and that everyone stay up to date with COVID vaccinations. Check to see if you are up to date on your COVID vaccines at: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html