Tomorrow marks the start of this year’s Edinburgh Science Festival, an annual event held since 1989 and the UK’s largest.

In 2020 the festival was cancelled due to Covid-19 restrictions, three weeks before it was due to begin. But this year it’s back, with a blend of online and in-person events including many outdoor activities. Along with showcasing recent scientific discoveries, it includes an online event looking at false scientific information and what we can do to counter it.

Most scientists and researchers are aware that false information and conspiracy theories exist but we’re not really trained to know what to do about it. Our role is to conduct the studies, review wider evidence and try to communicate the findings. We also need to be prepared for criticism of our work and keep an open mind about the fact that we might have got it wrong, or that there is uncertainty. Normally this is resolved by others replicating our findings or indeed disproving them with different or better research. However, sometimes things presented as scientific ‘facts’ are just completely without substance and can cause real harm.

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This is the case with some of the information we’ve seen circulating on Covid-19 vaccines. Here I think researchers do need to step up and call out misinformation and be prepared to explain why something simply isn’t true. So what are some of the most common myths about these vaccines?

One of the most worrying claims has been that vaccines can lead to infertility and affect the human reproductive system. There is no evidence for this and it is often used as an argument to dissuade people from taking up other vaccines or medicines. As the Royal College of Obstetricians and Gynaecologists have made clear, there isn’t even a biologically plausible mechanism why fertility would be affected. Couples planning a pregnancy, and women who are pregnant are eligible for the vaccines and should be offered them at the same time as others in their age group.

Two of the vaccines approved for use in the UK are messenger RNA (mRNA) vaccines made using a new technology that uses a nanoparticle to deliver genetic instructions to human cells to help the immune system to attack the virus. This may have contributed to claims that Covid-19 vaccines can ‘rewrite’ your DNA. There is no basis for this claim as the vaccines don’t interact with DNA or indeed the centre (nucleus) of our cells where DNA is located.

One of the more bizzare claims about Covid-19 vaccines is that they make people magnetic. We even saw scenes of a nurse in the USA trying to make a key stick to her neck in a court hearing in the USA where a bill was being considered to address civil liberties in relation to vaccines. The key fell off. The argument used is that vaccines have metal in them that can cause a magnetic interaction with objects. But there are no metals in Covid-19 vaccines.

Another common misperception is that the vaccine may lead to testing positive for Covid-19 in future (on a lateral flow or PCR test). There is no basis for this, as these tests are designed to test for the virus, either its genetic material or proteins in the virus. If you take a serology (blood) test that looks for antibodies (usually as part of a study) the effect of vaccines will show up, but being vaccinated does not increase your chances of testing positive for the disease.

Perhaps the most common question about Covid-19 vaccines that is perfectly legitimate but has fuelled misinformation is about longer term consequences for health following vaccination. As a general question this is important to respond to, because even the tens of thousands of people who took part in the original trials for approved vaccines will now only be eight or nine months post second dose. They are still being followed up.

In addition, the ‘real world’ reporting of any adverse events or side effects following vaccination (such as the MHRA’s yellow card system in the UK) has only been in place since vaccines were rolled out from December 2019. Anti-vaccination campaigns have seized on this, calling the vaccines experimental and claiming that they will cause disease or even death in the longer term.

But here we can look back to other mass vaccination programmes that have been in place for decades. We know that adverse events show up soon after vaccination, in the first few days or weeks. This is the case with the side effects many experience after a Covid-19 vaccine such as a sore arm or flu-like symptoms, but also the extremely rare blood clots that may be linked to two of the adenoviral vector vaccines, Oxford Astra Zeneca and Janssen. Other vaccines such as for measles, mumps, polio, hepatitis, tetanus, diphtheria etc have not caused long-term health effects and we have no reason to believe that Covid-19 vaccines will either.

There are other myths about Covid-19 vaccines that might be contributing to vaccine hesitancy and that are circulating online. The best way to combat these is to provide accurate information and reassurance, and to make sure that information reaches people from trusted sources.

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We’ll be discussing this and much more on scientific disinformation at The Edinburgh Science Festival session presented by the Royal Society of Edinburgh and chaired by the veteran journalist Jim Naughtie. It takes place on Monday June 28th at 5:30pm and registration is free. I’ll be taking part and do join us if you can.

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