The Food and Drug Administration and Centers for Disease Control and Prevention are in disagreement with Pfizer over plans for a third COVID-19 shot.

Pfizer says it's ramping up efforts to develop a third dose that it hopes will better protect people from variants, citing waning immunity from its coronavirus vaccine.

Pfizer says it would soon publish data about a booster and submit it to the FDA, European Medicines Agency and other regulators for emergency approval.

However, the FDA and CDC came forward together with a different take. They say Americans don't need boosters yet and that it's not up to companies alone to decide when they might be needed.

Former U.S. Surgeon General Dr. Jerome Adams called out the lack of coordination between the government and vaccine companies.

"This whiplash really is troubling to the American people. But understand, vaccinations are your best bet right now, they're still incredibly effective,” he says.

Pfizer’s vaccine requires two doses to provide full immunity, but for months, it has been hinting at the need for a third dose, citing the possibility that immunity may weaken over time.

The debate comes as the Delta variant is becoming the dominant variant, spreading quickly across the U.S.

At Cox Health in Springfield, Missouri, 90% of coronavirus patients tested have the Delta variant.

"If we don't get enough vaccinating, there's going to be another variant that's probably worse…that's the way viruses work,” says Dr. Howard Jarvis, the medical director of the Emergency Department at Cox Health.

Pfizer says its research shows booster doses of its vaccine produces levels of neutralizing antibodies that are five to 10 times higher than what's produced after two doses.