Social media posts have sought to falsely link a recent increase in unexplained hepatitis in children to the Covid vaccine.
The affected children were mostly under the age of five and therefore ineligible for the injection, say health agencies monitoring the situation.
But that hasn't stopped other claims and theories about not sending children to school from being promoted as fact.
So, what are the proven facts of the cases so far?
As of April 21, 2022, the World Health Organization had recorded at least 169 cases of unexplained hepatitis – inflammation of the liver – in children in 11 countries since January. Of these, 114 were in the United Kingdom.
None of the five specific viruses (labeled A – E) that commonly cause hepatitis were found, but most of the young people tested tested positive for a particular adenovirus – a common family of infections responsible for illnesses ranging from colds to eye infections.
Dr Meera Chand, director of clinical and emerging infections research at the UK Health Safety Agency (UKHSA), said their investigations "increasingly" suggested the increase was linked to adenovirus infection.
"However, we are thoroughly investigating other possible causes," she said.
Vaccine 'finally' ruled out
The UKHSA says the Covid vaccine is the only thing they can definitively rule out – because none of the affected children had received the injection.
However, on Twitter, Reddit, Facebook and Telegram, the BBC has found false claims that these hepatitis cases were caused by the Covid vaccine.
A post on Reddit highlighted the fact that an adenovirus is used in the AstraZeneca and Johnson & Johnson Covid vaccines.
The adenoviruses used in vaccines are harmless carriers that have been modified so they cannot replicate or cause infection.
Not only are they completely different adenoviruses from those found in affected children, but these vaccines are largely restricted to use in people aged 40 and over in the UK.
The average age of children who develop hepatitis is three – an age group that is not eligible for any of the Covid vaccines in the UK, where most cases have been recorded.
An article from a website known to contain false and misleading information about Covid, claiming that the Pfizer vaccine was to blame, was shared on Facebook in English, Spanish, Italian, Chinese and Norwegian.
It cites a misinterpreted study, which has also been used to make misleading claims about vaccines and fertility.
(Full article by BBC, available in English)