Recently updated federal guidelines for childhood immunizations no longer include universal recommendations for the hepatitis A and hepatitis B vaccines, and the move has stoked fears among public health experts that these two previously well-controlled viral liver infections will mushroom into outbreaks in the United States, reported Medpage Today.

Meanwhile, thousands of miles away in Kerala, a coastal state in India, that scenario played out with a surge in cases of hepatitis A, a viral infection that affects the liver. Last year, through the final week in December, Kerala reported 32,000 confirmed and probable cases of the virus, along with nearly 80 deaths, according to Times Now News.

Most cases in Kerala were blamed on contaminated groundwater sources, unsanitary conditions and poor public health, news accounts reported.

Hepatitis A is caused by the hepatitis A virus (HAV). The virus is spread when fecal matter—even trace amounts—from someone with HAV gets into another person’s mouth.

Hepatitis B virus (HBV) is a highly contagious viral infection that can cause liver damage. The virus is easily spread via hep B–positive blood, semen or other bodily fluids. Pregnant women who have HBV can also transmit the virus to their babies, usually during birth. But people who have not been infected with HBV can be vaccinated against the virus to prevent infection.

Of note, hepatitis C virus also attacks the liver. Although there is no vaccine for hep C, treatment is easier and shorter than ever, and most people can be cured, usually by taking a daily pill for a month or two. For more details, see the Basics on Hepatitis C Treatment.

Untreated chronic hepatitis can lead to liver inflammation, fibrosis (scarring of the liver), liver cancer and the need for a liver transplant.

U.S. infectious disease specialists are concerned that both hepatitis A and hepatitis B might surge stateside after both vaccines were removed from the list of universally recommended childhood immunizations—reducing the number of vaccines from 17 to 11. The vaccines were delisted after an overhaul of federal guidelines by the Department of Health and Human Services resulted in the Centers for Disease Control and Prevention (CDC) no longer recommending that all newborns receive the hepatitis A and B vaccine. (What’s more, the CDC no longer recommends universal vaccination against RSV, flu, COVID or meningococcal disease.)

The guidelines advised that the hepatitis B vaccine be administered only to infants born to women who test positive for the virus and that other parents should discuss with their clinicians whether their infants should get the shots.

The decision was made despite the fact that the Vaccine Integrity Project, a group of U.S. health experts who provide additional science-based immunization guidance to health care providers and the public health community, found no benefits to diverging from the CDC’s previous longstanding childhood vaccination protocol.

“From a public health perspective, universal immunization against both hepatitis A and hepatitis B has been remarkably successful in this country,” William John Moss, MD, MPH, of the Johns Hopkins Bloomberg School of Public Health, told MedPage Today. “This will result—I think in at least some states or jurisdictions—in lower coverage, and children will be infected.”

A slew of states including Alaska, Arizona, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island and Vermont said they would continue to follow well-established guidance from the American Academy of Pediatrics that all infants receive a dose of the hepatitis B vaccine within one full day of delivery.

To learn more about previous cases of hepatitis outbreaks that made the news, read “LA County Declares Hepatitis A Outbreak” and “Mysterious Hepatitis Outbreak Hitting Kids in U.K. and U.S.”