Feature Article: 3 Misconceptions About the Hepatitis Outbreak in Children

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In late April 2022, several cases of hepatitis of unknown cause were reported in children in the U.S. and several other countries. Investigations into these, and additional cases, are currently underway.

Hepatitis is a medical term used to describe inflammation of the liver. However, because some viruses include the word “hepatitis” in their name, it is easy to be confused. So, let’s take a closer look at what hepatitis is, discuss why these cases are causing concern, and address some misconceptions related to the situation.

What is hepatitis?

Hepatitis is a term used by healthcare providers to describe inflammation of the liver. Typically, an inflamed liver is not functioning properly, leading to symptoms like nausea or vomiting, pain, dark urine, light-colored bowel movements or diarrhea, joint pain, or yellowing of the skin or the whites of the eyes (called jaundice). However, not everyone with hepatitis experiences symptoms, making it difficult in some cases to know that a person’s liver is under stress.

Hepatitis can be caused by several viruses. Hepatitis A, hepatitis B, and hepatitis C may come to mind when one thinks about liver infections (perhaps even the less commonly known, hepatitis D and hepatitis E), but hepatitis can result from a variety of causes, including:

  • Other viruses, such as adenovirus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, Yellow fever virus and Dengue virus
  • Bacterial infections, particularly if they are severe enough to infect the bloodstream (called sepsis)
  • Repeated consumption of large amounts of alcohol over time
  • Chemicals, including poisons or medications
  • Autoimmune disorders
  • Genetic disorders, such as Wilson disease
  • Dietary supplements

The condition can be short-lived or chronic, meaning it does not resolve and eventually can lead to liver disease or liver cancer, such as can occur with hepatitis B infections.

Why are the current cases so concerning?

The recent cases of hepatitis in children are alarming for a few reasons:

  • Although the number of cases is small, collectively, they are occurring at higher rates than would typically be expected.
  • Some of the children are experiencing severe enough liver damage that they require liver transplants, and a few have died.
  • The cause has yet to be determined. While a few hypotheses have been generated, it remains unclear why these children are getting hepatitis. Many of the children have tested positive for a particular type of adenovirus, called adenovirus type 41, but not all of the children have had this virus. It is possible that in some cases, adenovirus was not detected due to timing or quality of specimens or other testing limitations. Furthermore, adenovirus type 41 does not cause the extent of liver damage being experienced in this situation. However, if adenovirus is the cause, it will be incumbent upon us to figure out why. Potential reasons for more severe disease could include a novel form of the virus, lower immunity to adenovirus due to fewer exposures during the pandemic, or co-infection with another virus, such as SARS-CoV-2, the virus that causes COVID-19. Although, importantly, not all of the children had a history of COVID-19 either.

Investigations into the causes are ongoing in several countries, including the U.S.

Three things to know about the current hepatitis outbreak in children

When we don’t know why something is happening, we try to figure it out. Often, we do this by looking for patterns, such as what the child was doing before developing symptoms. It is human nature to do this, and it is an important part of the process of finding answers. Unfortunately, this same process can result in misunderstanding or confusion as people share ideas, especially in today’s connected world. As such, we wanted to address three ideas about this situation that are unlikely or unfounded, but which have spread, causing fear and confusion.

1. The current situation is not the result of weakened immune systems due to COVID-19 lockdowns.

While it is likely that children have less immunity against certain viruses, like adenovirus, because of lack of exposure during the pandemic, that is different than having a weakened immune system. The immune system is robust, and it works all day every day — the same as our heart, lungs and their associated systems. The things we touch are not sterile. The food we eat is not sterile, and the air we breathe is not sterile. This means that our immune systems work 24/7 regardless of whether we are in our homes and away from others or going about our usual business. As such, even while increased numbers of contagious infections may be likely, increased severity of infections should not be assumed. For example, adenovirus infections are generally a nuisance, but for most people they are not deadly, so if an adenovirus is found to be the cause, we will need to understand why we are seeing the increased severity. As described above, it could be that the virus has changed. Alternatively, if the number of severe cases is significantly higher, that could result in an increase in severe outcomes. However, that would not provide evidence that our immune systems were weakened by the social distancing and other public health measures instituted to save lives during the pandemic.

2. The current situation does not mean the hepatitis B vaccine given at birth does not work.

Because of confusion about use of the word “hepatitis,” some have suggested that this situation offers evidence that the hepatitis B vaccine does not work. However, as described above, hepatitis B is one of many pathogens that can cause hepatitis. To date, none of the affected children were found to have infections caused by any of the same-named viruses (hepatitis A, B, C, D or E). As such, the situation does not offer evidence that either the hepatitis A or hepatitis B vaccine is ineffective.

3. The current situation is not related to the adenovirus used in COVID-19 vaccines.

Some have confused the adenovirus discussed in relation to this situation (type 41) and the adenovirus vectors used in some COVID-19 vaccines (types 5 and 26). In addition to being different types of adenovirus, the COVID-19 vaccines made using adenovirus vector viruses (J&J/Janssen and AstraZeneca) are not approved for use in people younger than 18 years of age. The children experiencing hepatitis are 16 years of age and younger.


Finding the cause of these cases of hepatitis is important, particularly as we witness children becoming so ill that they require hospitalization and, in some cases, surgical intervention in the form of a liver transplant. And, sadly, a few children have died. However, it is also important that we critically analyze what we know about the situation, so that we are not overcome with fear or misinformed by ill-founded ideas circulating on the internet.

To stay abreast of the situation, monitor several sources of information to see what they are reporting, or check primary sources, such as the World Health Organization or the Centers for Disease Control and Prevention.

If you have questions specific to your child, contact your child’s doctor. If you are concerned that your child may be displaying symptoms of hepatitis, contact your child’s doctor or seek emergency medical treatment if needed.

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Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel.