Professor Úna Fairbrother on how false claims about paracetamol and autism put public health at risk.
Date: 25 September 2025
Messaging coming from the current president of the USA and promoted by social media is dangerous, misinformed and is done for votes, clicks and likes without troubling with ethics, integrity or expertise. The latest regards false information about paracetamol, autism and triple vaccinations.
The scientific consensus remains that paracetamol (or Tylenol as it’s known in the US) is the safest choice for pregnant women when needed. While some studies hint at an association between heavy use and neurodevelopmental issues like Autism Spectrum Disorder (ASD), this link is not proven to be causal and is outweighed by the known, verifiable risk of untreated high fever to the foetus. Similarly, decades of rigorous global research have definitively proven that the triple MMR vaccine (Measles, Mumps, and Rubella) does not cause autism.
So-called ‘evidence’ against vaccines is often heavily politicised and can easily be enhanced with AI, bearing little actual regard for real people. Health advice is particularly vulnerable to this manipulation.
We have just come out of a global pandemic where over seven million people died, with over 700,000,000 cases reported, though the true figures may be much higher. This was against a background of lurid anti-vaccination, science fiction-type, conspiracy theories ranging from laughable (vaccines make us magnetic) to terrifying (huge numbers will die from the vaccine).
Millions of Lives Saved
Routine childhood immunisation efforts are estimated to have prevented over 154 million deaths worldwide in the 50 years between 1974 and 2024, according to the World Health Organisation. More recently, a Lancet study has estimated that in the 12 months to 8 December 2021 over 14 million lives worldwide were saved through the COVID vaccination alone. This was the largest public health intervention in history, and it succeeded. But this hasn’t helped to stem the wave of anti-science rhetoric or profound mistrust that has been amplified through modern means of communication.
Why Understanding Science is Hard (and Why Education Matters)
I have taught molecular science to students at UK universities for over 25 years and know that understanding science data is not straightforward. It needs background knowledge, critical thinking skills and trusted sources of information. Universities are essential in creating a population who have these skills.
Scientific evidence is rarely or never absolute, so we offer percentages and probabilities, using words like ‘suggests’ and ‘risk’, leading people to suppose that we are not sure or clear. Even using raw statistics can be open to interpretation: a 25% risk, for example, is judged differently by every person based on their life experience and the severity of the situation (think the chance of being run over today versus the chance of it raining on your barbecue). This confirms why we must prioritise high-quality, expert advice over isolated statistics.
A Dangerous Argument
It is much easier to peddle bland assumptions with clear and emphatic messaging (we will stop autism by stopping paracetamol use in pregnancy) than to explain something nuanced, complex and case-specific, which may require education and balancing of information.
These false arguments often have a clever structure that flows a bit like ths:
- statement of fact - increasing levels of autism reported,
- moving to some real research - risks of paracetamol and pregnancy have been investigated (appealing to the ‘no smoke without fire’ mentality),
- then leading into some propaganda style messaging, with an emotional appeal often using evocative and suggestive language – ‘I want to say it like it is, don't take Tylenol. Don't take it. Fight like hell not to take it.’
This style of argument is powerful when promoted by a figure who has social standing or popularity (from a president to an influencer). When it relates to human health, it creates an especially dangerous cocktail.
The US president has used our current ‘conspiracy-ready’ environment to suggest that paracetamol causes autism and to cast fresh doubt on childhood vaccinations. This is based on a failure to grasp the complexity of data and the risk vs benefits for individual pregnant women. There has certainly been an increase in individuals identified with autism, but experts attribute much of this rise to increased awareness, the widening of diagnostic criteria, and earlier screening, and scientists are also working hard to understand what other factors are contributing.
More Vulnerable Society
A population now primed to mistrust vaccinations are easier to frighten. Fewer people are now being vaccinated, and in the UK alone this has led to an increase in childhood diseases that we had almost eradicated a few decades ago, such as measles, mumps and rubella. Individuals who cannot have vaccinations due to poor health are at higher risk of contracting these diseases from unvaccinated infected individuals. All of these diseases can cause life-changing harm, even death, in children.
It is terrifying that, should we have another pandemic similar to COVID, we would be in a worse position to mitigate its ravages, both through vaccination hesitation and reduced ability to produce a vaccine. The latter is due to the attack on American scientific research, which is so often world-leading, by Trump’s abrupt removal of billions of dollars of funding.
Look to Trusted Sources
In the UK, there are some trusted sources that offer science-backed medical advice:
Pregnant women in our university community and in the UK at large, who are concerned with the use of paracetamol to manage their health conditions or anyone concerned about their vaccination status, are best placed to discuss this with their GP and, if appropriate, maternity services or health visitors. Our medical practitioners are highly informed and able to give case-specific advice, advice that is in your best interests, not theirs.
