Southwest CEO Gary Kelly has tested positive for COVID-19 after testifying at a Senate hearing Wednesday alongside other airline executives, a Southwest spokesperson said.

He was not masked during the hearing.

Kelly, who is fully vaccinated and boosted, has mild symptoms, the spokesperson said.

ABC News reached out to the airlines whose executives were next to Kelly at the hearing.

United Airlines CEO Scott Kirby and Delta operations chief John Laughter tested negative Friday.

American Airlines CEO Doug Parker plans to test Friday afternoon, according to the airline. Sara Nelson, international president of the Association of Flight Attendants-CWA, said she will test Friday and in the coming days.

Senate Commerce Committee Chair Maria Cantwell told ABC News that committee members will "follow the protocols" for testing.

-ABC News' Mina Kaji, Allison Pecorin and Sam Sweeney

More than 4,700 COVID-19 patients are in Ohio hospitals, the highest number of all of 2021 -- and hospitalization numbers are quickly approaching an all-time high, Gov. Mike DeWine's office said.

DeWine said he's calling up 1,050 National Guard members to help overwhelmed hospitals beginning on Monday.

The potential timeline for when children under 5 may have an authorized vaccine is now being pushed back.

Data for a two-shot vaccine was initially expected by the end of the year, but now Pfizer/BioNTech say they hope to have data with a third shot in the first half of 2022.

Pfizer/BioNTech said they "will amend the clinical study evaluating the safety, tolerability, and immunogenicity of the Pfizer-BioNTech COVID-19 Vaccine in children 6 months to under 5 years of age. The study will now include evaluating a third dose of 3 µg at least two months after the second dose of the two-dose series to provide high levels of protection in this young age group."

An early look into the study data suggested that the two doses at a smaller volume was not as effective for kids ages 2 to 5 as it was for the 16 to 25 population, so scientists are going to add a third dose and see if the vaccine is as effective. There were no safety issues reported in the early data analysis.

Pfizer/BioNTech added in a statement, “The decision to evaluate a third dose of 3 µg for children 6 months to under 5 years of age reflects the companies’ commitment to carefully select the right dose to maximize the risk-benefit profile. If the three-dose study is successful, Pfizer and BioNTech expect to submit data to regulators to support an Emergency Use Authorization (EUA) for children 6 months to under 5 years of age in the first half of 2022.”

-ABC News' Eric M. Strauss

Americans in their 30s are accounting for the highest case rate of any age group, according to federal data.

The U.S. is now reporting nearly 120,000 new cases each day. The daily case average has surged by nearly 86.3% since late October, according to federal data.

Thirty-three states, as well as Washington, D.C., and New York City, have seen at least a 10% jump in daily cases over the last two weeks.

New Hampshire currently holds the nation's highest case rate, followed by Rhode Island, Maine, Wisconsin, Connecticut and Massachusetts, according to federal data.

-ABC News' Arielle Mitropoulos

Indonesia announced Thursday its first confirmed case of the omicron variant.

The case was detected in a janitor who works at the COVID-19 Emergency Hospital of Kemayoran Athletes Village in Jakarta, according to a statement from Indonesian Health Minister Budi Gunadi Sadikin.

The hospital's cleaning staff are routinely tested and the results for three people were positive for COVID-19 on Dec. 10. Those samples were then sent to a genome sequencing lab, which identified the omicron variant in one of the samples on Wednesday, according to the statement.

Indonesia's Ministry of Health has also identified probable cases of omicron among five travelers who were in quarantine -- two Indonesian citizens who had just returned from the United Kingdom and the United States, and three foreigners from China. Their test samples are being sequenced and the results will be known in a few days, according to the statement.

The health minister urged Indonesians "not to panic and to remain calm," and to get vaccinated against COVID-19 if they haven't already.

"The arrival of new variants from abroad, which we identified in quarantine, shows that our defense system against the arrival of new variants is quite good, we need to strengthen it," Sadikin said. "So it's normal to stay 10 days in quarantine. The goal is not to make it difficult for people who came, but to protect the people of Indonesia."