What you should know about the hepatitis B vaccine for newborns

A vaccine that helps prevent liver disease is back in the spotlight as a federal advisory panel considers delaying the first shot for infants.

The hepatitis B vaccine is a multi-dose series typically first administered at birth and then through the first months of infancy. The vaccine is safe and effective — it’s credited with preventing millions of infections since its addition to the childhood vaccine schedule.

But the Advisory Committee on Immunization Practices, or ACIP, is expected this week to reconsider how soon infants receive the first vaccine shot. The panel considered delaying the newborn shot in a September meeting, but held off.

Medical groups have repeatedly warned that the panel has been politicized since its members were handpicked by Health and Human Services Secretary Robert F. Kennedy Jr., an anti-vaccine activist. Several members have limited relevant experience and have expressed vaccine skepticism.

Doctors say removing the birth dose could expose children to unnecessary chronic illness. It’s not clear if the panel will change the timeline for the rest of the shots in the hepatitis B series.

Here’s what you need to know about the hepatitis B vaccine.

What is the hep B vaccine?

The vaccine helps prevent hepatitis B, a viral infection of the liver that can cause both short-term and chronic disease, including liver damage, liver cancer and death. Up to 2.4 million people in the United States have hepatitis B, and many do not know they’re infected.

Up to 90 percent of newborns infected with hepatitis B develop chronic disease. But when the hep B vaccine is given within 24 hours of birth, it is also up to 90 percent effective in preventing perinatal infection.

How does hep B spread?

Hepatitis B is spread through blood and body fluids. While it’s often associated with sexual activity and intravenous drug use, it can also pass from a birthing parent to a child during delivery. While it is rare, hepatitis B can be transmitted by saliva if there is an undetectable amount of blood — and through other people in a newborn’s life who might not even know they’re positive.

Instances of potential exposure can include a child coming into contact with blood from a close person’s skin cut or biting, including in a day care setting. Hepatitis B can also live outside the body for up to seven days. Still, the topic of hep B can make some parents uneasy or make them feel like it says something about the morality of their private lives.

“There’s a whole reframing about how hepatitis B can be transmitted that needs to happen, and it’s not going to be an easy fix,” said Andrea Love, an immunologist and microbiologist who has examined the hep B vaccine in her newsletter.

Is a universal birth shot really needed if a birthing parent doesn’t have hepatitis B?

In June, a key member of the revamped ACIP explained their interest in reexamining the newborn hep B shot.

“Unless the mother is hepatitis B positive, an argument could be made to delay the vaccine for this infection, which is primarily spread by sexual activity and intravenous drug use,” said Dr. Martin Kulldorff, the former chair of the panel.

That rationale doesn’t take into account that not all pregnant people are screened for hepatitis B — insurance claims data from 2014 showed gaps in testing among pregnant people with commercial insurance and Medicaid. The Centers for Disease Control and Prevention estimates that between 12 percent and 16 percent of pregnant people do not receive enough prenatal care to screen properly for hepatitis B. And some are screened early enough in pregnancy that it leaves a window open for later infection.

“There are cracks in our screening during pregnancy,” said Dr. David Higgins, an assistant professor of pediatrics at the University of Colorado School of Medicine. “The birth dose is a safety net in case they fall through the cracks.”

In the early 1980s, the hep B vaccine was only recommended for high risk populations including children of parents who had tested positive for the virus. But limiting newborn shots to risk-based cases did not decrease cases — about 18,000 infants and children were infected annually at the time. This led to ACIP’s expanded recommendation in the early 1990s for a universal birth shot.

What are the implications of removing the newborn shot?

If the panel proceeds to drop the universal birth shot, it will be one of the first major shake-ups to the childhood vaccine schedule under Kennedy.

Medical experts have warned that delaying the hepatitis B vaccine could lead to more children in the United States infected and developing long-term health issues. Before routine vaccination was implemented in the early ’90s, an estimated 18,000 infants and children became infected with hepatitis B annually. Infant infections have since dropped by 95 percent.

It can be difficult to measure the impact of a delayed shot because hepatitis B can silently damage the liver until it becomes more deadly later in life. But for a single year of delaying the shot by two months for babies born to a birthing parent whose hep B status is unknown, researchers estimate it could lead to more than 1,400 infections, 300 cases of liver cancer and more than 480 related deaths. A delay to 12 years could lead to 2,700 infections, 500 cases of liver cancer and more than 780 related deaths.

Since the panel’s recommendations help determine what vaccines in America are covered by insurance, a change in the schedule could create new out-of-pocket costs for families. But a major health insurance group has announced that its members intend to keep covering ACIP-recommended vaccines that were in place at the start of September at no cost to patients through the end of 2026.

Still, there are questions about the long-term availability of the vaccines in hospitals and future coverage.

“There are a lot of unanswered questions,” Higgins said. “A recommendation like this does not just affect whether a provider says, ‘Oh, I think this is a good idea,’ or ‘Hey, the CDC recommends this.’ It affects whether the hospital chooses to stock it, and it affects whether insurance is going to pay for it.”

Why are anti-vaccine activists opposed to this shot? 

Anti-vaccine activists for years have spread misleading information about the hep B vaccine, in part by tying hep B primarily to sexual activity and drug use. A pregnant person who has hepatitis B can spread the virus to their newborn during delivery. But activists have asked why a pregnant person who has tested negative for the virus should still get the shot for their baby — even though it can spread in other ways.

Kennedy has questioned the safety of the vaccine. Casey Means, a wellness entrepreneur and nominee for surgeon general, has connected hep B and sexual activity in interviews.