The Food and Drug Administration is set to authorize a third vaccine dose for any Americans with weak or compromised immune systems, the New York Times reported Wednesday.

The news came shortly after the Centers for Disease Control and Prevention announced that it estimates more than 1 million people who received the Moderna or Pfizer COVID-19 vaccines went back for what they're calling an "unauthorized" third dose as a booster shot.

What are the details?

The move could come as soon as Thursday, according to the outlet's Sharon LaFraniere and Noah Weiland, who noted that the decision is an "effort to better protect [those people] as the highly contagious Delta variant sweeps the nation."

In addition to helping those with compromised immune systems — who reportedly make up at least 3% of the American population — the third shot is also said to help those people who have had organ transplants.

People with weakened immune systems include those with a systemic disease diagnosis, histories of cancer, and those who have long used certain medications such as corticosteroids.

"The Food and Drug Administration's decision to authorize a third shot for organ transplant recipients and those with similarly compromised immune systems will be considered by an advisory committee to the Centers for Disease Control and Prevention, scheduled to meet on Friday," the outlet added in its report. "Although the FDA's action is independent of the panel's recommendation, in practice many physicians wait to act until the CDC weighs in."

If the committee votes to greenlight the shots, the CDC could issue a same-day recommendation, providing further guidance to physicians and pharmacists about how to move forward with the dosing.

What else?

On Wednesday, KGO-TV reported that at least 1 million people across the country received an unauthorized third COVID-19 shot as a booster against the deadly disease.

"Florida is among the states reporting the highest number of people opting for a booster shot," the station noted, "followed by Ohio, California, Illinois, and Tennessee."

The estimated amount, the station added, is likely an "undercount" because though the numbers include two-dose Moderna and Pfizer vaccines, it does not count those who may have received two shots of Johnson & Johnson's one-shot vaccine.

It remains unclear whether those people who took advantage of the third shot did so under physicians' orders.