The new booster shot is a bivalent vaccine, meaning that it targets two versions of the coronavirus: the original strain and the Omicron subvariants BA.4 and BA.5, which became the dominant subvariants in the United States over the summer. The previous booster shot targeted only the original version of the virus.
On Sept. 1, the new shot became the only booster recommended for people ages 12 and older.
If you are being vaccinated against Covid for the first time, you will, however, receive the original vaccines that were introduced in late 2020.
