COVID-19 updates: 345 children currently hospitalized with coronavirus in Texas

Dr. Paul Offit, a member of the U.S. Food and Drug Administration's vaccine advisory committee, said a two-dose COVID-19 vaccine "appears to be enough" to curb infection, rather than adding a booster shot.

"You look at states in the United States that have high immunization rates with a two-dose vaccine, it appears the two doses appears to be enough to be able to control this infection," Offit, who is also the director of the Vaccine Education Center at Children's Hospital of Philadelphia, told ABC News on Thursday night. "I think the critical issue here is not going to be boosting the vaccinated. I think if we really want to get on top of this pandemic, it's going to be about vaccinating the unvaccinated."

The FDA's vaccine advisory committee is set to hold a key meeting on COVID-19 vaccine booster shots on Sept. 17, just three days before the Biden administration plans to begin offering the shots to Americans.

"If the companies or the FDA can make a case that there has been an erosion in protection against severe critical disease and that that erosion in protection against severe disease would be mediated or eliminated by a third dose, then we could move forward," Offit said. "But to date, we really need to see those data to be able to make that decision."

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‘Boosting the vaccinated’ not as key as ‘vaccinating the unvaccinated’: Expert

Dr. Paul Offit, a member of the FDA’s vaccine advisory committee, discusses what will determine if the committee recommends COVID vaccine booster shots for most Americans.

ABCNews.com

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

Eight school districts in Florida told the state's education commissioner that they would not reverse their mask requirements for students, clearing the way for the state to retaliate by withholding the salaries of school board members.

The eight districts -- Duval, Hillsborough, Indian River, Leon, Miami-Dade, Orange, Palm Beach and Sarasota -- each wrote a letter to Commissioner Richard Corcoran Wednesday saying they believed they were following state law and had no plans to stop requiring face coverings for students.

Corcoran had given each district until 5 p.m. Wednesday to reverse their mandates, threatening to recommend to the state education board that it withhold the salaries of board members if they did not change course.

The state education department announced Monday it would take such action against board members in Alachua and Broward counties over their school mask mandates.

On Friday, a Florida judge ruled that school boards can enact student mask mandates and ordered the state education department to stop enforcing a state rule requiring districts to allow parents to opt-out.

-ABC News' Will McDuffie

A new study out of Israel finds that certain cancer patients may see roughly equal vaccine protection as the general population. 

Specifically, the study found a group of 154 cancer patients with solid tumors had an antibody response roughly equivalent to an equally-matched group of people without cancer six months after their second Pfizer shot. A subset of cancer patients undergoing chemotherapy, however, were the most likely to have antibody levels below a detectable threshold.

The study also found the Pfizer vaccine was safe for solid tumor cancer patients. 

The study implies that not all cancer patients may need a third booster shot to achieve equal levels of protection as the general population. Presently in the U.S., the CDC and FDA say "moderate to severely" immune compromised people need a third shot -- which comprises roughly 3% of the U.S. population. 

-- ABC News’ Sony Salzman