Georgia Representatives Nikema Williams and Hank Johnson are among a group of more than 30 Democratic lawmakers urging the Centers for Disease Control and Prevention to keep its long-standing recommendation that all newborns receive the hepatitis B vaccine within 24 hours of birth. They're warning that any delay could put babies at serious risk.

A letter, led by Rep. Williams, Rep. Kim Schrier of Washington, and Rep. Johnson, was sent to Acting CDC Director James O'Neill ahead of the agency's Advisory Committee on Immunization Practices (ACIP) meeting this week. The panel is expected to vote Friday on whether to continue recommending the birth dose or change the guidance to delay the shot.

In their letter, the members of Congress pressed the CDC to maintain the current guidance, which has been in place since 1991, noting that there is no data to support delaying the first hepatitis B shot to one month, four years, or even 12 years of age. They highlighted that 116 countries recommend the universal birth dose, and since the U.S. adopted the policy, childhood hepatitis B infections have dropped by 99%.

"As mothers, fathers, and Members of Congress, we share your goal of reducing and eliminating childhood and lifelong illnesses," they wrote. "To protect children from hepatitis B, we strongly urge you to maintain the existing ACIP recommendation in support of the birth dose of the hepatitis B vaccine."

The lawmakers also said they were relieved that ACIP postponed a vote in September, but remain "very concerned" that the committee could reverse the recommendation during its December meeting.

Their letter underscores the high stakes associated with timing. Babies exposed to hepatitis B at birth or in infancy have a 90% chance of developing chronic hepatitis B, which carries long-term risks of liver cancer and other life-threatening complications. The virus is 100 times more infectious than HIV, can be transmitted by caregivers or relatives who may not know they are infected, and can survive on surfaces for seven days, the members wrote.

According to the American Academy of Pediatrics, infants infected within the first year of life have a 90% chance of developing chronic hepatitis B, and one in four of those with chronic cases will die from the disease.

The CDC's two-day ACIP meeting began Thursday, but the hepatitis B vote was pushed to Friday after confusion over the wording of the questions the panel was set to consider. Committee members said they had seen three different versions of the voting language in the past 72 hours. Technical issues prevented updated wording from being displayed on slides, and no printed copies were available. The presentation was eventually postponed until the end of Friday's agenda.

The hepatitis B vaccine has been recommended for newborns in the U.S. for more than three decades. Research shows that giving the vaccine soon after birth is up to 90% effective in preventing mother-to-child transmission. Completing the full three-dose series provides immunity for 98% of babies, according to the AAP.

Hepatitis B is an incurable virus spread through blood and bodily fluids. The CDC estimates that half of the 2.4 million people in the U.S. with hepatitis B do not know they are infected. Adults often show few or no symptoms, which experts say makes the birth dose even more important.

The vaccine has become a target of vaccine skeptics, including Health and Human Services Secretary Robert F. Kennedy Jr., who falsely claimed earlier this year that the shot is a "likely culprit" in autism. Kennedy has appointed all current members of ACIP during his tenure.

In their letter, Williams, Schrier and Johnson said the evidence supporting the vaccine is overwhelming. They noted that the current schedule has prevented an estimated 6 million infections, saved more than 90,000 lives, and averted nearly 1 million hospitalizations over the past 30 years. A model from the Center for Disease Analysis Foundation found that removing the universal birth dose could lead to 99,000 new hepatitis B infections across the U.S. over the next three decades.

Read the full letter here.