Placebos

If you’ve had both of your COVID vaccinations, you may have suffered some side-effects – perhaps headaches, fatigue, fever or a sore arm. These effects are mainly caused by your immune system’s reaction to the vaccine. But most scientists agree that there is another cause: the human mind.

The ability of the mind to generate the symptoms of illness is known as the “nocebo” effect. The nocebo effect is the unpopular twin brother of the placebo effect. Whereas the placebo effect alleviates pain and the symptoms of illness, the nocebo effect does the opposite: it generates pain and symptoms.

A 2018 study found that almost half of participants in placebo trials experience side-effects, even though they are taking inert substances. 

There was a similar finding in the first major trial of the Pfizer COVID vaccine in 2020. In the placebo group – who were not given the vaccine – between a quarter and a third of people reported fatigue, a similar number reported headaches, and around 10% reported muscle pain.

Indeed, Martin Michaelis and Mark Wass, bioscientists at the University of Kent, recently suggested that “for some vaccinated people the knowledge that they have been vaccinated may be sufficient to drive side-effects”.  READ MORE