For those who suffer from side effects after a COVID vaccination, the unpleasant symptoms are probably worth it – even if they don’t have to experience them.
According to the U.S. Centers for Disease Control and Prevention, about 77 percent of those who received the vaccine dose from Pfizer, Moderna, or Johnson & Johnson received at least one local vaccine, such as headache, fever, or fatigue. reported no symptoms. muscle pain.
But a new study published in the journal JAMA Network Open On Tuesday, nearly two-thirds of these symptoms were found to be spontaneous due to what researchers call the “nosebo” effect.
Scientists at Beth Israel Deaconess Medical Center in Boston claimed that many volunteers in vaccine control groups – those who unknowingly received an inert, placebo vaccine – had flu-like symptoms, such as vaccinated cohorts.
“Non-specific symptoms such as headache and fatigue, which we found to be particularly sensitive to the nosebo, are listed in many data sheets as among the most common adverse reactions after COVID-19 vaccination.” says senior researcher Ted J. Kaptchuk, a professor of medicine. This is stated in a statement from Harvard Medical School.
“Evidence suggests that this type of data may misrepresent people’s daily background feelings caused by the vaccine or lead to anxiety and worry that make people overly alert to their body’s feelings about adverse events,” he added. said Kaptchuk.
Researchers reported that recipients of both the vaccine and placebo recently reported adverse effects at similar rates – 22,802 and 22,578 reports, respectively, based on data collected from 12 vaccine trials.
More than 35% of placebo recipients experienced at least one systemic symptom, i.e., not related to the injection site. Headache is the most common, 19.6%, fatigue – 16.7%. For comparison, 46 percent of actual vaccine recipients reported experiencing at least one systemic symptom.
However, 16 percent of placebo recipients reported local effects such as pain, itching, and swelling at the injection site after the first dose, while approximately 66 percent of actually vaccinated volunteers experienced similar local effects.
The figures suggest that at least two-thirds reported by individuals treated with the active vaccine may be related to the nosebo effect, as the researchers found that the same symptoms occurred in the placebo group. .
As participants switched to additional doses, the number of those who reported adverse symptoms after the second placebo stroke decreased by 32% and local discomfort by 12%.
However, for the conscientious vaccine group, their reporting of a systemic reaction increased to 61%, while the effect of the injection site increased to 73%. According to the researchers, this may be the result of participants expecting symptoms for the second dose, which results in a psychosomatic response that matches their expectations.
Further research suggests that the nosebo effect may be responsible for up to half of all side effects reported after the second dose for those receiving two-dose therapy, such as Pfizer and Moderna.
The researchers acknowledged the limitations because the 12 trials included in the study had different approaches to reporting symptoms and were based on different vaccine types – mRNS, protein-based, and viral vector.
Kaptchuk said he hopes their study will “help reduce concerns about the COVID-19 vaccine, which will reduce hesitation in vaccination.”