The upcoming COVID-19 booster is expected to be available in the United States as early as next week -- potentially as soon as Sept. 13 -- and is expected to protect against severe disease and death from currently circulating variants.

First, the Food and Drug Administration is expected to authorize or approve the shots, which they have signaled they are likely to do within the next seven days.

Next, the Centers for Disease Control and Prevention's independent panel of advisors is set to meet on Sept. 12 to provide a recommendation on who will be eligible for the shots. The CDC director is expected to sign off, with shots to be available soon after.

It remains to be seen who the advisers will recommend should receive the updated booster. Additional protection is especially important for those most at risk, such as those over 65 years old and those with immunocompromised conditions, experts say.

What is this new vaccine formula?

The updated booster shot is formulated to target XBB.1.5, an omicron subvariant.

It is a monovalent vaccine, meaning it only targets one strain (the previous bivalent booster was formulated with the original strain and BA.4/BA.5).

Will this new vaccine protect against new variants?

So far, data shows this booster will offer additional protection against severe disease and death for all currently circulating variants.

Vaccine manufacturers tell ABC News they continue to test the updated booster on newer variants, including the newer omicron sub-variant BA.2.86.

Early lab-based results published Wednesday in a press release from Massachusetts-based biotechnology company Moderna show the updated booster generated a nearly nine-fold increase in antibodies against BA.2.86. New York City-based pharmaceutical company Pfizer is likely to release similar data on its new vaccine soon.

Previous results from Moderna indicated that its updated booster offered additional protection against the sub-variants EG.5 and FL.1.5.1, which are currently dominating in the U.S. and make up an estimated 36% of new cases.

When will this new vaccine booster be available?

The updated booster shot is expected to be available as soon as September 13, following the CDC director’s signoff.

Should I wait to get this new booster or get a shot now?

Health experts recommend that it is best to wait for the updated booster shot to maximize protection this fall and winter.

Should I get a booster shot if I recently had COVID?

You may consider delaying your vaccine by three months from when your symptoms started or a positive test, according to the CDC.

Can I get the flu shot and COVID booster at the same time?

At this time, health officials say getting both shots in the same session is safe and effective.