Hepatitis, which is an inflammation in the liver, is a common infection in the U.S. and worldwide. And two forms of hepatitis – A and B – are extremely preventable, especially if you get a vaccine that protects you against them.
Below, we’ll explain how hepatitis A and B vaccines work, how effective they are at preventing infection, and how long you’re protected if you get them. We’ll also go over recommendations on who should get hepatitis vaccines, the recommended vaccine schedule for children and more.
What are the hepatitis vaccines and how do they work?
The hepatitis A and B vaccines are inactivated, meaning they use dead or inactivated strains of the hepatitis virus that help teach your immune system how to identify and fight off a hepatitis infection if you’re ever exposed. The most important thing to remember about this vaccine and others that protect you from preventable illness is that while you may experience mild side effects, you can’t get sick just from getting vaccinated.
Hepatitis vaccines require repeated doses to be fully effective, including booster doses in some situations. The three vaccines that protect against hepatitis A and B are:
- Hepatitis B vaccine – This vaccine can be given to infants, children and adults to protect against hepatitis B only. Depending on the brand, you may receive two or three doses of this vaccine.
- Hepatitis A vaccine – This vaccine can be given to infants, children and adults to protect against hepatitis A only. There are two types, one that requires two doses, and one that requires three doses.
- Hepatitis A and B combination vaccine – This vaccine is given to adults to protect from both hepatitis A and B. There’s only one combination vaccine approved for use in the U.S. (brand name Twinrix), and it’s given in a series of three doses.
How the hepatitis vaccines work
The hepatitis vaccines work by introducing a safe form of the virus to the body, prompting the immune system to make antibodies. Antibodies are something the body develops in response to a vaccine or an infection to prevent a future infection.
So, if you receive the hepatitis vaccine(s) or you’ve had and recovered from hepatitis, antibodies will be present to help your immune system recognize and fight off harmful bacteria and viruses, giving you long-term protection from future illnesses.
How effective the hepatitis vaccines are at preventing infection
The hepatitis vaccines are very effective. According to the Centers for Disease Control and Prevention (CDC), since the hepatitis B vaccine was added to the recommended vaccination schedule in 1982, cases of hepatitis B have declined significantly – virtually eliminating the disease in children 19 years old and younger. Studies have also shown that at least 90% of young adults, and over 90% of infants, children and teenagers, develop antibodies after completing a two or three dose series of the hepatitis B vaccine.
While the rate of adults ages 19-59 diagnosed with hepatitis B has declined significantly, the goal to eliminate the disease in the U.S. by 2030 has stalled. This is due to underreporting of the illness and missed vaccinations. But vaccination is still important – people who get it have an 80-100% protection against the disease. If vaccination is delayed or skipped, and you’re exposed to and get hepatitis B, it can lead to a number of serious conditions, including a lifelong infection, liver disease, liver cancer, and even death.
Since the introduction of the hepatitis A vaccine in 1996, cases have declined significantly, with many people showing long-term immunity. Just one dose has been shown to provide immunity for several years for at least 94% of people who receive it, with two doses increasing immunity.
However, in recent years, cases of hepatitis A in the U.S. have been increasing. This is due to a number of factors, including vaccine misinformation and limited access to health care for certain groups. It’s also become more widespread with the increase in international travel, as hepatitis A is the most common vaccine-preventable illness contracted while traveling outside of the U.S.
How long the protection from the hepatitis vaccines lasts
Because the hepatitis B vaccine has only been in widespread use since the early 1980s, lifelong immunity status isn’t completely known. However, studies have shown that protection after the vaccine is at least 20-30 years, and potentially lifelong.
The hepatitis A vaccine has been in widespread use since the 1990s. After full vaccination, protections are thought to last for at least 25 years in adults, and 14-20 years in children. And like the hepatitis B vaccine, protection is possibly lifelong.
People who live in a country where hepatitis isn’t endemic (or regularly occurring) and don’t have risk factors, such as using injectable drugs, are more likely to be immune for life. And while immunity after vaccination can wear off over time, the CDC says that most people who receive the recommended hepatitis vaccinations have long-term and even lifelong immunity.
The CDC, vaccine scientists and health care professionals recommend that everyone get vaccinated against hepatitis A and B. But it’s important to speak with your doctor for a recommendation tailored to your unique needs. Recommendations for both vaccines vary for infants, children, adults and pregnant women, but vaccination is generally recommended for:
- All infants
- Children and adolescents under 19 years old
- Adults 19 through 59 years old who haven’t been vaccinated or are unsure of their vaccination status
- Adults aged 60 and older who want to be protected from hepatitis, even without risk factors for hepatitis B
They also recommend one or both vaccines for the following people:
- International travelers
- People who have an occupational risk of infection, including those that work in health care settings like a hospital
- Adults who think they’ve been exposed to hepatitis and aren’t sure of their vaccination status
- People with diabetes
- People who use illegal injectable or noninjectable drugs
- Men who have sexual contact with other men
- Sexually active people who are not in long-term mutually monogamous relationships
- People seeking treatment for a sexually transmitted infection
- People who have end stage kidney disease
- Staff and residents of institutions or group homes
- Household members and intimate partners of people with a chronic hepatitis B infection
- People who anticipate close contact with an international adoptee
- People experiencing homelessness or who are unhoused
- People living with HIV
- People who have chronic liver disease
- People who have hepatitis C
- People who are incarcerated
Hepatitis vaccine schedule for children and teens
Following the recommended vaccine schedule for children is extremely important to best protect them from preventable illnesses like hepatitis A and B.
For babies, the hepatitis B vaccine is given in three doses:
- The first dose within 24 hours of birth
- The second dose at 1-2 months old
- The third dose at 6-18 months old
- When combination vaccines, which protect against hepatitis B and other preventable childhood illnesses, are used, a fourth dose of the hepatitis B vaccine may be given. This is typical and safe.
The hepatitis A vaccine is given to babies in two doses:
- The first dose at 12-23 months old
- The second dose at least 6 months after the first dose
Infants ages 6 to 11 months traveling outside of the U.S. should receive the hepatitis A vaccine before travel. It won’t offer long-term protection if given before 12 months of age, so following the recommended vaccine schedule at 12 months and beyond is recommended.
Older children and adolescents not previously vaccinated should receive the full vaccine schedule as soon as they’re able.
Hepatitis vaccine recommendations for pregnant women
The CDC recommends that if you’re pregnant and have risk factors for hepatitis, and haven’t been vaccinated against hepatitis A and B, you should receive the vaccines during pregnancy. Your doctor may also encourage vaccination if you’re at higher risk for exposure.
All hepatitis vaccines are safe for pregnant women and the benefits of vaccination outweigh the risks. Also, since both vaccines are inactivated, it means the risk of complications for your baby is extremely low. However, it’s important that you speak with your doctor about what’s best for you.
People for whom the vaccine isn’t currently recommended
Vaccines are safe, and people rarely have reactions from them. However, there may be some components of the hepatitis vaccines that may cause an allergic reaction in some people. Speak with your doctor if you’ve ever had a reaction to a hepatitis vaccine, or if you have any severe life-threatening allergies. They can help determine the best protection against hepatitis for your specific situation.
Possible side effects of the hepatitis B vaccine
As with any vaccine, it’s possible to experience side effects. But experiencing side effects due to either hepatitis vaccine is rare, and they’re typically mild if you do experience them. They can include:
- Tenderness, swelling, warmth, redness or a lump at the injection site
- Headache
- Low-grade fever (100.4o F)
- Nausea
- Loss of appetite
However, certain rare reactions can be severe and life threatening. If you or your child are experiencing symptoms from the vaccines like difficulty breathing, swelling of the face or throat, dizziness, weakness or a fast heartbeat, call 911 or go to the hospital immediately.
Why it’s important to get the hepatitis A and B vaccines
Hepatitis affects the liver, a critical organ in the human body. Your liver helps with filtering your blood from harmful substances, aids in digestion, and performs a lot of other functions to keep you healthy. For your sake (and your liver’s) it’s important to protect yourself from preventable illnesses like hepatitis A and B with the vaccines.
Hepatitis A can be spread through contact with contaminated water or food, causing a milder illness than hepatitis B, which can be spread through contact with infected blood or bodily fluids. While most infections of both can clear up on their own with proper treatment, and hepatitis A can’t become chronic (long term), if not treated properly, hepatitis B may become chronic and lead to liver damage, liver cancer, cirrhosis and even death.
Protect yourself from hepatitis A and B
The best way to protect yourself and your loved ones from hepatitis A and B is by getting the vaccines. But there are other ways to protect yourself and those around you, including practicing safe sex, having good hygiene, avoiding the use of injectable drugs, taking precautions when traveling internationally, and choosing a business with good cleaning practices when getting tattoos and piercings.
