An outbreak of hepatitis of unknown etiology in children across the world is not caused by COVID-19 vaccines. Of course, anti-vaxxers are trying to use this hepatitis outbreak as more fear, uncertainty, and doubt about the COVID-19 vaccines, but the evidence doesn’t support it.
As of this time, we don’t know a lot about this hepatitis outbreak, like routes of infection and the causative agent, but it is ringing the alarm bells at various public health agencies across the world.
In this article, I will walk you through the hepatitis outbreak and then some limited data that appear to show that there is no link to either COVID-19 or COVID-19 vaccines.
What is this hepatitis outbreak?
The World Health Organization (WHO) and Centers for Disease Prevention and Control (CDC) are each reporting an outbreak of hepatitis in children across the world. The disease has an unknown etiology (cause).

In the WHO report published on May 27, 2022, scientists confirmed 650 probable cases of acute hepatitis of unknown etiology in children have been reported to the WHO from 33 countries in five WHO Regions between April 5th and May 26th. Additionally, 99 cases are pending classification. There has been a 100% increase in cases from April to May.
The WHO stated, “The actual number of cases may be underestimated.”
The WHO stated that they have ruled out hepatitis A, B, C, D, and E, so this appears to be a new form of hepatitis, although researchers have yet to uncover what is causing it.
According to the latest Joint Surveillance Report by the WHO Regional Office for Europe (EURO), as of 20 May 2022 WHO has observed the following:
- 75.4% of cases are <5 years of age.
- Of 156 cases with information on hospital admission, 22 (14.1%) were admitted to an intensive care unit. Of the 117 cases for which this information was available, 14 (12%) have received a liver transplant. Usually, hepatitis C is the only one that might require a liver transplant after liver failure, so this is troubling.
- Overall, 181 cases were tested for adenovirus by any specimen type, of which 110 (60.8%) tested positive. The positivity rate was the highest in whole blood specimens (69.5%).
- Of the 188 cases PCR tested for SARS-CoV-2, 23 (12.2%) tested positive. Serology results for SARS-CoV-2 were only available for 26 cases, of which 19 (73.1%) had a positive finding.
- Of the 63 cases with data on COVID-19 vaccination, 53 (84.1%) were unvaccinated.
So let’s go over some points about this data.
First, it’s a bit scary that a new form of hepatitis with unknown etiology is circulating in children. There aren’t a lot of cases yet, but it’s spread across the world, so scientists are diving into this disease to see what may be happening.
Second, as part of their due diligence WHO researchers tried to determine if adenovirus or SARS-CoV-2 are correlated with the outbreak. WHO stated:
Based on the working case definition for probable cases, laboratory testing has excluded hepatitis A-E viruses in these children. SARS-CoV-2 and/or adenovirus have been detected in a number of the cases, although the data reported to WHO are incomplete. The United Kingdom has recently observed an increase in adenovirus activity, which is co-circulating with SARS-CoV-2, though the role of these viruses in the pathogenesis is not yet clear.
In other words, WHO researchers are unsure if either disease is related to the hepatitis outbreak. However, there appears to be some preliminary information from the UK that could establish a link between one variant of adenovirus with the hepatitis outbreak:
Adenovirus has been found in 75% of the cases tested in the United Kingdom, but the data for other countries are incomplete. Of the small number of samples that have so far been typed, a majority have been confirmed for Type 41 adenovirus (in the United Kingdom, in 27 of 35 cases with an available result). Adenovirus associated virus 2 (AAV-2) has also been detected in a small number of cases in the United Kingdom using meta-genomics in liver and blood samples. However, many of the remaining cases did not have appropriate samples taken, highlighting the importance of appropriate sampling (whole blood) to further characterize the type of adenovirus detected. Additionally, Type 41 adenovirus infection has not previously been linked to such a clinical presentation in otherwise healthy children.
Adenovirus 41 is known to cause gastroenteritis, and other variants and species of adenovirus have been linked to hepatitis, so it is not surprising that the World Health Organization is focused on whether there is some level of correlation between adenovirus and this hepatitis outbreak.
The WHO states:
While adenovirus is a plausible hypothesis as part of the pathogenesis mechanism, further investigations are ongoing for the causative agent; adenovirus infection (which generally causes mild self-limiting gastrointestinal or respiratory infections in young children) does not fully explain the more severe clinical picture observed with these cases. Factors such as increased susceptibility amongst young children following a lower level of circulation of adenovirus during the COVID-19 pandemic, the potential emergence of a novel adenovirus, SARS-CoV-2 co-infection or a complication of previous SARS-CoV-2 infection, leading to superantigen-mediated immune cell activation, proposed a causal mechanism of multisystem inflammatory syndrome in children need to be further investigated.

Are COVID-19 vaccines related to this outbreak?
In the small sample size of 63 patients with this new hepatitis, where the vaccine status was known, 84% were unvaccinated against the COVID-19. This very preliminary data seems to indicate, if it indicates anything at all, that the risk of this new hepatitis may be increased in individuals who are unvaccinated. But, I would not establish any type of conclusion based on this type of data.
WHO has been examining whether adenovirus is involved with the outbreak not only because the virus has been co-circulating with SARS-CoV-2, but also because it may actually be the causal factor of the hepatitis outbreak.
The COVID-19 vaccines from JNJ and AstraZeneca use an adenovirus vector to transfer an mRNA fragment to the cell. This induces the cell to produce the spike protein, similar to true mRNA vaccines. The adenovirus vector cannot replicate and there is no evidence that this or any other adenovirus is linked to hepatitis.
The CDC and WHO are taking this situation very seriously and are continuing to monitor the outbreak and test for infectious agents that may be linked to the hepatitis cases.
Let me repeat myself, just in case. There is no evidence whatsoever that links COVID-19 vaccines of any type to this hepatitis outbreak. Again, quoting the World Health Organization:
Hypotheses related to side effects from COVID-19 vaccines are currently not supported as most of the affected children did not receive these vaccines.
Citations
- Schaberg KB, Kambham N, Sibley RK, Higgins JPT. Adenovirus Hepatitis: Clinicopathologic Analysis of 12 Consecutive Cases From a Single Institution. Am J Surg Pathol. 2017 Jun;41(6):810-819. doi: 10.1097/PAS.0000000000000834. PMID: 28296681.