Are hepatitis cases in children related to the J&J COVID-19 vaccine? No, that's not true: The claim that the adenovirus vector in the Johnson & Johnson COVID vaccine is related to youths being diagnosed with hepatitis is not possible because that vaccine is not approved for children in the United States nor in the United Kingdom as of April 25, 2022.
The claim appeared in an Instagram post on April 23, 2022:
(Source: Instagram screenshot taken on Mon Apr 25 19:21:20 2022 UTC)
The Instagram post is a screen grab of a tweet by Brad Campbell, a "chiropractic Internist," with a reply by Stanton Hom, a "prenatal/pediatric chiropractic specialist."
The posts appear to be related to recent news stories that children are being diagnosed with hepatitis in the U.K. and the United States. The BBC reported that "Adenovirus probable cause of mysterious child hepatitis."
In the United States the J&J/Janssen vaccine is not approved for use by people under 17, according to the Centers for Disease Control and Prevention, as of April 25, 2022. Thus the J&J vaccine could not be causing the hepatitis. "Currently, the Pfizer-BioNTech COVID-19 vaccine is the only vaccine authorized or approved for children ages 5 through 17 years," the website says.
(Source: CDC website screenshot taken on Mon Apr 25 19:23:54 2022 UTC)
According to the National Health Service in England, only the Pfizer/BioNTech vaccine has been approved for children 5 to 15. "Which COVID-19 vaccine will children get? Children will be given the Pfizer/BioNTech (Comirnaty) vaccine for both doses. You can read the Pfizer/BioNTech COVID-19 vaccine patient information leaflet on GOV.UK."
None of the children in the U.K. who have been diagnosed with hepatitis received a COVID-19 vaccine of any kind, according to gavi.org:
Importantly, none of the children diagnosed with hepatitis in the UK have received a COVID vaccination, so there's no basis to believe COVID vaccines have anything to do with this spike.
The BBC, citing the UK Health Security Agency, also reported that "none of the children involved has been vaccinated."