JAN 21, 2022 3:30 PM PST

Negative side effects from the COVID-19 vaccine may be all in your head

WRITTEN BY: J. Bryce Ortiz

Did you suffer from a headache, fever, or body aches and chills after you received the COVID-19 vaccine? You aren’t alone. As the United States Centers for Disease Control (CDC) found, over 77% of people reported at least one negative reaction to the first dose of the vaccine. A new study, published in the Journal of the American Medical Association, reported that a high percent of reported adverse side effects following COVID-19 vaccinations may arise from a psychological phenomenon similar to the placebo effect. 

Many of us have heard of the placebo effect. As the video below explains, this effect describes a phenomenon in which an individual believes a placebo drug (i.e., an inert, non-therapeutic drug such as a sugar pill) is effective and expects and/or shows a clinical improvement in response to the fake drug. Some researchers have studied the neurobiological underpinnings of the placebo effect, which have shed light on the brain regions and neurotransmitters involved in the positive effects of placebos. 

Additionally, psychological effects, such as the conscious or unconscious expectation that a therapy will work, play a large role in the placebo response. That is, if you expect a treatment will be beneficial, you are more likely to experience beneficial outcomes. Similar to the placebo effect, an opposite phenomenon exists called the nocebo effect. The nocebo effect often occurs when you expect that a treatment will be harmful, and as such, you will more likely experience negative effects in response to treatment. For example, if we are told that a vaccine will possibly lead to body aches, chills, headache, and fatigue, then we are more likely to experience one or all of these negative symptoms after receiving the vaccine. 

In the published study, the researchers performed a meta-analysis of randomized, placebo-controlled COVID-19 vaccine trials. They then compared the rates of reported adverse side effects by participants who received the actual COVID-19 vaccine to side effects reported by individuals who received a placebo vaccine (a saline injection). Interestingly, while individuals who received the actual vaccine reported more adverse side effects, close to one-third of people who received the placebo vaccine also reported an adverse side effect. The researchers then performed an analysis that suggested the nocebo effect accounts for up to 76% of all adverse side effects in individuals who received the COVID-19 vaccine. 

Ted Kaptchuk, the lead author of the study, said that, “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-19 vaccination in many information leaflets.” He suggests that this information may lead individuals to misattribute common background sensations to vaccine side effects and make individuals hyper alert about bodily feelings following vaccination. 

The researchers hope that their findings may help to start conversations about the nocebo effect among health care providers and their patients, with the belief that these conversations can reduce worry about the COVID-19 vaccine and help to decrease vaccine hesitancy. 

 

Sources: CDCthe Journal of the American Medical AssociationThe Journal of NeuroscienceThe Journal of Neuroscience

About the Author
PhD in Neuroscience
Science and medical writer | Researcher | Interested in the intersection between translational science, drug development, and policy
You May Also Like
NOV 11, 2021
Immunology
Some Patients Left Vulnerable to COVID Even After Getting Vaccinated
NOV 11, 2021
Some Patients Left Vulnerable to COVID Even After Getting Vaccinated
Global vaccination efforts continue in the backdrop of the ongoing pandemic. However, new studies demonstrate how severa ...
DEC 21, 2021
Immunology
Shark Immune Proteins as Pandemic 'Insurance'?
DEC 21, 2021
Shark Immune Proteins as Pandemic 'Insurance'?
Sharks are incredibly hardy creatures—they've survived in marine ecosystems, often unchallenged predators, for ...
DEC 22, 2021
Coronavirus
Which COVID vaccine and booster are right for me?
DEC 22, 2021
Which COVID vaccine and booster are right for me?
The 2-year anniversary of the COVID-19 pandemic, which began in December 2019, recently passed. It would not be overstat ...
FEB 17, 2022
Immunology
A Post-vaccination Workout Boosts Immune Responses
FEB 17, 2022
A Post-vaccination Workout Boosts Immune Responses
  A workout after getting a vaccine for influenza or COVID-19 may provide additional immune protection, says a new ...
MAR 10, 2022
Health & Medicine
New Study States Natural Immunity to COVID Lasted up to 15 months in the Majority of Its Cohorts
MAR 10, 2022
New Study States Natural Immunity to COVID Lasted up to 15 months in the Majority of Its Cohorts
From the beginning of the pandemic to late January 2022 during the Omicron wave, the CDC estimates that 43% of the US po ...
APR 01, 2022
Cannabis Sciences
Can weed cure Covid?
APR 01, 2022
Can weed cure Covid?
Since legal cannabis has gained momentum throughout the country, so have the reports that it's the cure all for everythi ...
Loading Comments...