The American Medical Association, American Pharmacists Association and American Society of Health-System Pharmacists are calling for an "immediate end" to prescribing, dispensing or using the deworminig drug ivermectin to treat or prevent COVID-19.

Ivermectin is available in different formulations for both people and animals to treat parasites. It is not approved to treat or prevent COVID-19, nor is there enough evidence to support its use. Though amid a surge in COVID-19 cases in the U.S., internal data from the Centers for Disease Control and Prevention reviewed by ABC News estimates a 19-fold increase of the medicine being distributed during the first week of August, alongside an increase in reported cases of illness related to ivermectin toxicity.

The prescribing and dispensing of ivermectin has increased 24-fold since before the pandemic, according to the medical and pharmaceutical associations, which said in a joint statement they were "alarmed" by an exponential increase in recent months as well.

"[We] are urging physicians, pharmacists, and other prescribers -- trusted healthcare professionals in their communities -- to warn patients against the use of ivermectin outside of FDA-approved indications and guidance, whether intended for use in humans or animals, as well as purchasing ivermectin from online stores," the associations said. "Veterinary forms of this medication are highly concentrated for large animals and pose a significant toxicity risk for humans."

-ABC News' Sony Salzman

Moderna has submitted initial data to the U.S. Food and Drug Administration on its vaccine booster, the pharmaceutical company announced Wednesday.

Its booster candidate would be half the dose (50 micrograms) of the original dosing (two shots of 100 micrograms each).

Federal officials have said they hope to begin administering booster shots for many Americans starting on Sept. 20, with the third shot at least eight months after the second.

The FDA has only authorized booster shots of Pfizer's and Moderna's COVID-19 vaccines for people who are immunocompromised. The Centers for Disease Control and Prevention's independent advisory board also recommended booster shots for those with weakened immune systems.

Pfizer is also seeking authorization for a third dose of its COVID-19 vaccine. The FDA announced Wednesday it will hold a public meeting of its independent advisory committee on Sept. 17 to discuss the application.

-ABC News' Eric Strauss

Even with the delta variant, schools are still safe for children if guidelines are followed, CDC Director Rochelle Walensky said Wednesday at a town hall with the National Parent Teacher Association.

For the most part, Walensky said, "there's more disease happening outside of school than there is happening within a school."

Walensky, a mother of three, said she understands why parents are anxious.

But she added, "What we do know is when we implement the guidance for safe schools -- we implement the masking, the ventilation strategies, the cohorting and the screening strategies -- that we can have our kids be safe."

American Academy of Pediatrics President Dr. Lee Beers said at the town hall that it's still a very small percentage of children who get severely sick. The U.S. saw 200,000 cases among kids in the last week with about 2,000 of them hospitalized, Beers said.

-ABC News' Cheyenne Haslett

With nearly 104,000 hospitalized, U.S. hospitalizations are now at the highest point in more than seven months, according to federal data.

Alabama's ICUs remain 100% full while Georgia's ICUs are over 96% full, federal data show.

Nearly 1,000 COVID-19 deaths are now being reported in the U.S. each day, the highest average in more than five months.

-ABC News' Arielle Mitropoulos

Two studies to be published Friday found fewer pediatric hospitalizations among children and communities with higher vaccination rates, the director of the U.S. Centers for Disease Control and Prevention said.

In one study, national data from August showed that children were nearly four times more likely to be hospitalized with COVID-19 in the states with the lowest vaccination rates when compared to states with the highest rates -- proof that "cocooning" children with vaccinated people keeps them safe, Dr. Rochelle Walensky said at a White House briefing Thursday.

The second study, which looked at hospitalizations rates in 12- to 17-year-olds across 14 states during July, found that adolescents who were unvaccinated were 10 times more likely to be hospitalized with COVID-19 than their fully vaccinated peers, Walensky said.

"Both studies, one thing is clear: cases, emergency room visits and hospitalizations are much lower among children and communities with higher vaccination rates," Walensky said. "We must come together to ensure that our children, indeed, our future, remain safe and healthy during this time."

-ABC News' Cheyenne Haslett