Experts say that up to three quarters (or more) of the side effects from the Covid vaccine could be “all in your head.” 

People around the globe claim that they have experienced headaches, diarrhoea and tiredness after being jabbed. 

Harvard scientists believe that the majority of these side effects can be attributed to the “Nocebo” effect. This is a phenomenon where someone experiences an unpleasant side effect after a jab just because it was expected.

Researchers analyzed reports of 44,000 participants on side effects after being jabbed.

But half of the participants were not told they had actually been given a placebo, or fake vaccine — such as a saline solution.

According to researchers, many people claimed that side effects caused by jabs are actually due to ‘background feelings’ which were not related to jabs.

The researchers claimed that people became hyper-alert to vaccine-related problems because of their anxiety. 

The above graph shows the proportion of trial participants that got the Covid vaccine which reported experiencing side effects from the jab. These results were compared to reports of side effects in the placebo group. A ratio of side effects reported in the placebo and vaccinated group was then calculated. This allowed scientists to determine what proportion of side effects in the vaccinated group were likely not due to the jabs (striped areas)

Below is a graph showing the percentage of participants in the trial who reported side effects after receiving the Covid vaccine. This was compared with side effect reports from the placebo group. The ratio of side effect reported by the placebo group and those in the vaccinated was calculated. Scientists were able to calculate the percentage of side effects that could have been caused by the jabs.

The study examined side effects rates in approximately 22,000 individuals who were administered the Covid vaccine as part of clinical trials.

The fake vaccine was administered to an identical control group. 

Placebos can be used as a part of routine clinical trials to determine if a treatment works. 

Is there a placebo or nocebo effect?

To test the effectiveness of a treatment, studies usually include placebo groups.

In Covid vaccine trials, these volunteers were not told they were receiving a fake treatment —  or saline solution — in the place of a vaccine.

These patients were treated in exactly the same manner as those who had been vaccinated. They also received two injections.

The scientists include this group in order to determine if the treatment works and cancel the nocebo and placebo effects.

The placebo effect is a phenomenon where people are more likely to expect a positive outcome because of their positive expectations.

However, there is the nocebo phenomenon. This is where someone who has a negative expectation is more likely than others to experience a negative outcome.

Ted Kaptchuk (a world-renowned authority on the placebo effect) stated that this likely affected vaccine trials. 

The results showed that 46 percent of those vaccinated said they experienced adverse side effects such as headaches or exhaustion following the initial dose.

After the second jab, this rose to 61% of the group.

A total of 66% also described local reactions, such as swelling, pain or redness upon the first jab.

The number of reported reactions also increased after the second dose to 73%. 

However, the placebo group showed the exact opposite.

About a third reported headaches after taking the medication. The proportion dropped slightly following the second dose.

For local reactions to the injection site (which fell from 16% to 12%) by the second jab), the pattern was again repeated. 

According to scientists, it was possible that someone in the placebo-group could claim they have had an allergic reaction to the vaccine even though they didn’t receive the vaccine as they expected.

It was also possible to claim that people receiving the jab had experienced a negative result, even though it didn’t happen.

This phenomenon is known as the “nocebo effect” and it is where someone asserts that they had a bad reaction to treatment because they thought they would. 

To determine the likely percentage of side effects not caused by vaccines in jabbed individuals, scientists created a ratio.

The side effects rates in the vaccine and placebo groups were compared to determine how many of them were truly triggered. 

According to them, 76% of the headaches and fatigue reported after taking the first dose were due to the nocebo effects.

After the second dose, however, it dropped to 52%

Scientists believe that the amount of side effects from jabs is higher after the second dose, which was due to the increased immune system activity. 

They also stated that 25% of reactions to vaccines around injection sites were unlikely to be due to the initial dose and only 16% after the second.

Researchers found that people who received placebo had fewer adverse reactions to the second jab than those who were given the original. This was because the chance of experiencing one again after the second injection. 

According to them, this decreased their concern about having a reaction from the second injection and made it less likely that they would report one.

Ted Kaptchuk is a world-renowned expert on the placebo effect and was part of the research. He stated that it was obvious negative expectations led to side effects being incorrectly associated with vaccines.

He said: ‘Nonspecific symptoms like headache and fatigue — which we have shown to be particularly nocebo sensitive — are listed among the most common adverse reactions following Covid vaccination in many information leaflets.

Evidence suggests that such information could cause individuals to mistakenly attribute common background sensations like those arising from vaccinations.

‘Or [it could]People can feel anxiety or worry about the future, which may lead to fear and panic. 

Published in JAMA Open Research, the study is now available.

It included jabs made by AstraZeneca, Pfizer and Moderna — all in used in the UK.

This included the Johnson and Johnson jab that is used in the US and not the UK as well as some vaccines currently in clinical trials.

To establish if the trial has an impact, clinical trials include placebo groups.

Subjects who are given sugar pills or injections of saline to treat diabetes, will be treated exactly as those in the treatment group.

In Covid vaccine trials placebo groups were double-blind — meaning neither they or the scientists administering the vaccines knew who was getting the actual vaccine. 

The British health regulator has listed headaches as side effects after getting the vaccine. This affects around 10% of those who have received it. 

Since the start of the rollout, more than 50 million doses of medication were distributed. The MHRA received over 1.4million side effects reports.

Many complaints, however, are due to conditions such as ear and eye problems or indigestion that have not been connected with vaccines.

However, regulators have also been able use the data to detect blood clots or other uncommon side effects, and determine what complications occur more frequently than they expected.