As Prime Minister Benjamin Netanyahu entered the chamber, Senate Majority Leader Chuck Schumer did not shake his hand.

Notably, a group of Senate Democrats sitting in the front row middle section of the chamber, including Schumer and Sen. Mark Kelly, stood but did not clap as Netanyahu entered the chamber -- and many of them are not clapping at the applause lines that the majority of the chamber is clapping for.

In the earliest stages of his remarks, the group is seeming to be very strategic about which sentiments they do clap for.

Though they didn't clap at Netanyahu's entrance, they did all rise and stand to clap when Schumer said, "America and Israel must stand together."

The group that appears to be being selective with their clapping includes Sens. Gary Peters, Kirsten Gillibrand, Kelly, Maggie Hassan, Cory Booker, Alex Padilla, Schumer, Debbie Stabenow, Richard Blumenthal and Amy Klobuchar.

Twenty-one Senate Democrats and Vice President Kamala Harris were not in attendance for Israeli Prime Minister Benjamin Netanyahu's address to Congress.

Thirty senate democrats were in the chamber on Wednesday. Sen. Ben Cardin, the chairman of the Senate Foreign Relations Committee, is presiding over the chamber.

Notably, Rep. Rashida Tlaib -- the only Palestinian-American in Congress -- is sitting in the House chamber. She has said in the past Netanyahu should be arrested and is a war criminal. As Netanyahu entered the chamber, she remained seated.

Majority Leader Chuck Schumer is in attendance and sitting front and center on the aisle.

Sen. Mark Kelly, a potential vice president pick for Kamala Harris' presidential campaign, is seated in the second row.

-ABC News' Lauren Peller and Allie Pecorin

No cases of poliovirus infection have been reported in Gaza yet, days after evidence of poliovirus was detected in wastewater across Gaza, Gaza Ministry of Health's first care manager, Dr. Musa Abed, told ABC News.

Before the start of the conflict in October 2023, Polio vaccination coverage -- conducted through routine immunization -- was estimated at 99% in 2022, Abed said, confirming a United Nations report.

However, this number decreased with the outbreak of the war. The latest World Health Organization-UNICEF routine immunization statistics said that the number fell to approximately 89% in 2023 as newborns did not get vaccinated.

"Premature infants, children, and those with weak immunity are the groups most in need of these vaccinations," Abed added.

He explained that people who were vaccinated before the war do not need to repeat the vaccination "because vaccination consists of several doses once in a lifetime."

The Israel Defense Forces said it is planning to vaccinate troops that have been deployed to Gaza to prevent polio infection "to maintain the health of both the soldiers and Israeli citizens."

-ABC News' Diaa Ostaz, Jordana Miller, Emma Ogao and Morgan Winsor

Vice President Kamala Harris will meet separately with Israeli Prime Minister Benjamin Netanyahu after he meets with President Joe Biden, according to a White House official, who said that this was the plan prior to Biden announcing he’s exiting the race.

A cease-fire-hostage deal is believed to be close to being secured, with the United States saying to the Israelis, that it's "too good a deal to pass up," the official said.

-ABC News' Selina Wang