Outbreaks of unexplained hepatitis in children that began in 2022 have been linked to adeno associated virus 2 (AAV2) in three studies looking at cases in the UK and the US.
The mysterious cases of non-A to E hepatitis were first flagged in April 2022 in Scotland,1 and by July 2022 the World Health Organization had registered more than 1010 probable cases across 35 countries.2 As of July 2022, 15 cases in the UK had received a liver transplant and no deaths had been recorded.
All three studies, published in Nature under its accelerated article preview system, found that AAV2 was detected in nearly all the cases of unexplained hepatitis and that many of the children also had signs of infection with a helper virus, such as human adenovirus or herpesviruses. However, researchers have …