The above answers are great. Here is a link about the bivalent booster:
Updated vaccine boosters authorized for use as a single dose
www.fda.gov
COVID-19 Bivalent Vaccine Boosters
Updated vaccine boosters authorized for use as a single dose
11/29/2022
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The virus that causes COVID-19 changes over time. Keep your protection against COVID-19 up to date by getting a bivalent COVID-19 vaccine booster dose.
The bivalent COVID-19 vaccines include a component of the original virus strain to provide broad protection against COVID-19 and a component of the omicron variant to provide better protection against COVID-19 caused by the omicron variant. These are called bivalent COVID-19 vaccines because they contain these two components. A bivalent COVID-19 vaccine may also be referred to as “updated” COVID-19 vaccine booster dose.
COVID-19 vaccines can help protect against severe illness, hospitalization and death from COVID-19. As the virus changes and your immunity naturally decreases over time, you may lose some of that protection.
Search in your zip code to find a location where a bivalent COVID-19 vaccine booster dose is available near you.
Video:
Why should I get the updated COVID-19 vaccine now?[1:35]
The FDA authorized bivalent formulations of the Moderna and Pfizer-BioNTech COVID-19 vaccines for use as a single booster dose at least two months after completing primary or booster vaccination.
The
Moderna COVID-19 Vaccine, Bivalent is authorized for use as single booster dose in
individuals 6 years of age and older.
The
Pfizer-BioNTech COVID-19 Vaccine, Bivalentis authorized for use as a single booster dose in
individuals 5 years of age and older.
More at link.
ETA: I got the Pfizer bivalent booster in September. Minimal reaction to it.