What you need to know
- Hepatitis B can cause severe liver disease, cancer, and death. Ninety percent of infected infants develop a chronic infection.
- The hepatitis B vaccine provides lifelong protection against the infection and is most effective when administered at birth.
- The hepatitis B vaccine is safe, with a very low risk of serious side effects.
- There is no link between the hepatitis B vaccine and autism.
Hepatitis B is a viral infection that can cause liver disease in people of any age or lifestyle. Vaccination is 95 percent effective against the virus. But the hepatitis B vaccine has increasingly been the target of false and misleading claims about its safety and importance, especially for infants.
Here’s everything you need to know about the lifesaving hepatitis B vaccine.
What is hepatitis B?
Hepatitis B is a liver infection caused by the hepatitis B virus. The virus attacks the liver, causing severe short-term and long-term infections.
Short-term hepatitis B infections may cause fatigue, jaundice (yellow skin or eyes), dark urine or clay-colored stool, loss of appetite, nausea, and pain in the muscles, joints, and stomach.
A long-term hepatitis B infection occurs when the virus stays in the body beyond the initial infection, causing chronic illness. Hepatitis B infections become chronic in 90 percent of infected infants, half of infected young children, and between 5 to 10 percent of infected adults.
“Most people who go on to develop chronic hepatitis B do not have symptoms, but it is still very serious and can lead to liver damage (cirrhosis), liver cancer, and death. Chronically infected people can spread hepatitis B virus to others, even if they do not feel or look sick themselves,” says the CDC.
How does the hepatitis B virus spread?
The hepatitis B virus is spread through body fluids, including blood, semen, and saliva. It can also be transmitted from birthing parent to child during pregnancy and childbirth.
“While hepatitis B is an infection that lives in bodily fluids, it can survive outside the human body for several days, which means that sharing contaminated household products is a possible source of infection,” said Dr. Christopher Labos, a McGill University cardiologist and epidemiologist, in a 2019 article.
In 2022, over 250 million people worldwide had chronic hepatitis B, and 1.1 million died from the disease. Most of the deaths were from liver damage and liver cancer. Less than 15 percent of people living with hepatitis B have been diagnosed.
Why do doctors recommend the vaccine for babies?
Hepatitis B vaccination helps protect infants from a lifetime of potentially life-threatening infections and complications. Nine out of 10 unvaccinated infants infected with hepatitis B will develop chronic infections, which increases their risk of liver failure and liver cancer.
The hepatitis B vaccine is administered at birth to help prevent the virus from being transmitted from birthing parent to child. It also helps protect infants who might be in close contact with someone with hepatitis B. This is particularly important because most people who have hepatitis are undiagnosed.
Since the CDC began recommending hepatitis B vaccination at birth in 1991, chronic infections in children have decreased by 99 percent.
Is the vaccine safe?
Vaccines against hepatitis B were first developed in the 1980s, and they have been proven safe for decades. They have a low risk of serious side effects and are safe enough to be given to newborns, pregnant people, and immunocompromised people.
Decades of research have shown that the hepatitis B vaccine is safe and not associated with any safety concerns.
We also know hepatitis B vaccines work: “Between 1990 (about the time when universal hepatitis B vaccinations started) and 2006, the rate of hepatitis B infection fell by 81 percent to the lowest level ever recorded, and the decline was greatest among children,” added Labos.
Hepatitis B rates have continued to decline across all age groups, with the U.S. exceeding its goal of reducing new hepatitis B infections by 20 percent.
How well does the vaccine protect against hepatitis B?
Hepatitis B vaccination is up to 95 percent effective, providing lasting—and possibly lifelong—protection against the virus. Depending on when the first dose is given, the complete vaccine series consists of two to three doses.
The vaccine is most effective for infants and children. The American Academy of Pediatrics recommends that infants receive it at birth for the most protection.
The first dose is followed by two to three additional doses administered before 18 months. Children, adolescents, and adults who weren’t vaccinated as infants should also receive the vaccine.
Vaccination is particularly important for high-risk groups, including health workers and those who are in close contact with individuals living with chronic hepatitis B, people who use intravenous drugs, and people receiving blood transfusions, dialysis, or organ transplants.
How do we know the hepatitis B vaccine isn’t linked to autism?
Some people falsely claim that hepatitis B vaccines increase the risk of developing autism or other neurodevelopmental disorders. Yet, research has consistently shown there’s no link between autism and any vaccine, including the hepatitis B vaccine.
The myth that the hepatitis B vaccine causes autism came from a misrepresented CDC study on vaccines containing thimerosal, a preservative that has not been included in any childhood vaccines since 2001. The 2003 study found there is no link between thimerosal-containing vaccines and autism or ADHD, but vaccine opponents continue to misuse the data to claim the opposite.
Have more questions? Talk to your health care provider to learn more about hepatitis B vaccination.