Before Los Angeles students could enter their classrooms on the first day of school Monday, many waited in lines so staff could ensure they completed their daily pass health screening.

Los Angeles Unified School District students and staff had to be tested for COVID-19 by the first day of school, Los Angeles Mayor Eric Garcetti said last week. As the year gets underway, students will wear masks and undergo weekly testing regardless of vaccination status, ABC Los Angeles station KABC reported.

All school district employees are required to be fully vaccinated by Oct. 15.

Pfizer/BioNTech have submitted early booster shot data to the Food and Drug Administration. 

Phase 1 data found that people given a third shot eight to nine months after their primary doses had a boosted immune response and higher neutralizing antibody levels against the delta variant.

Pfizer/BioNTech plan to continue to study booster shots and submit additional data to the FDA.

It's not clear when or if the FDA and Centers for Disease Control and Prevention might recommend booster doses for all. Only severely immunocompromised people are currently eligible.

-ABC News' Sony Salzman

All health workers in New York state, public and private, must get vaccinated by Sept. 27, Gov. Andrew Cuomo announced Monday.

This includes staff at hospitals and long-term care facilities, including nursing homes, adult care and other congregate care settings.

Seventy-five percent of the state's hospital workers and 68% of nursing home workers are already vaccinated.

-ABC News' Aaron Katersky

As COVID-19 cases surge pediatricians are experiencing a first: sick children facing both respiratory syncytial virus, or RSV, and COVID-19.

"We've not seen this before -- we have two very highly contagious respiratory viruses circulating at the same time, particularly throughout the South around Texas and neighboring states," Dr. Jim Versalovic, pathologist-in-chief at Texas Children's Hospital, told ABC News Live on Monday.

Infants, young children and older adults are most at-risk for RSV, a respiratory virus that's usually more prevalent in the fall and winter. RSV kills 100 to 500 children under 5 each year, according to the Centers for Disease Control and Prevention.

"It's not surprising now to see children being impacted with both viruses, particularly infants and young children who are most susceptible to respiratory syncytial virus," Versalovic said.

He said in "recent weeks we've had 30% or more of our pediatric ICU beds [filled] with RSV infections," including some children also with COVID-19, which "could "mean more severe respiratory illness."

"We do know how to treat these children with RSV and with COVID. And so, for now we're managing that, but it is certainly a new challenge for us," Versalovic said.