Description: What does the science say? We have heard or used that question a LOT in these COVID days (years). It is a good question… an important question and one that is much better grounded than questions like; what do I think or what do I wish or what do I want to believe or what do I need to be true? We DO know from psychological research into cognitive biases that personal experience or related anecdotes can powerfully influence our beliefs, even in situations where there IS science that would show us a best bet depiction of what is likely true. This is called the availability heuristic. Now thinks about tis statement. I got the first COVID vaccination and I had a really bad reaction to it, my arm hurt for 5 days, I felt nauseous, stiff and sore and could not really do anything but sleep for 4 days. I think the shots are dangerous and I am not going to get anymore. Or, my friend got COVID and other than a runny nose had no other symptoms, … its not that bad and the shots cause problems so I am not getting anymore. We KNOW (yes, we do, don’t we?) that COVID vaccinations reduce the likelihood of infection and drastically reduce the likelihood of hospitalization or death if COVID is contracted after vaccination. Despite this large-scale health research some anti-vaxers and vaccine hesitant people seem to stick with their personal (available/vivid) experience. Is there OTHER research they might benefit from seeing? Well, have you heard of nocebos? Yes? If so how might they be at play in the “vaccination can be bad for you” belief? If not, well, either way, read the article linked below for a report on some science you likely have not been aware of (but should be!).
Source: COVID-19 vaccines: 76% of reported side effect may be due to ‘nocebo’ effect, Robby Berman, Medical News Today.
Date: January 25, 2022

Article Link: https://www.medicalnewstoday.com/articles/covid-19-vaccine-76-of-reported-side-effects-may-be-due-to-nocebo-effect
You likely have heard previously about placebos. Placebos or inactive (no active ingredient) versions of pills or shots are administered to part of the sample in a trial with the rest of those in the trial getting the shot or medication being investigated. Why? Well, because it has been consistently shown that getting what you think is a medication or treatment can have positive effects. Good medications are those that produce effects that are not just better than nothing but that are better than a placebo. Nocebos have similar effect but in the opposite direction. Due to this, the central finding of this research into nocebos, that 76% of the adverse experiences people had following a COVID vaccination are attributable to nocebo effects, is the most important. It suggests that a huge proportion of the experiences that get drawn into individuals’ decision-making about vaccination experiences are not caused by the vaccines used. Of course, now that we have this scientific data, the real challenge is to figure out how to make vaccine hesitant and anti-vaxers not only aware of it but to get them to use it to push aside their availability heuristic-based decisions. Now THERE is a place where more research IS needed.
Questions for Discussion:
- What is the availability heuristic and how might it be playing out in the decisions of anti-vaxers and the vaccine hesitant?
- What is a nocebo and how might its effects be involved in vaccination hesitancy?
- How might we utilize this research on nocebos to reduce vaccination hesitancey?
References (Read Further):
Sever, P. (2022). Nocebo affects after COVID-19 vaccination. The Lancet Regional Health–Europe, 12. Link
Haas, J. W., Bender, F. L., Ballou, S., Kelley, J. M., Wilhelm, M., Miller, F. G., … & Kaptchuk, T. J. (2022). Frequency of Adverse Events in the Placebo Arms of COVID-19 Vaccine Trials: A Systematic Review and Meta-analysis. JAMA network open, 5(1), e2143955-e2143955. Link
Colloca, L., & Miller, F. G. (2011). The nocebo effect and its relevance for clinical practice. Psychosomatic medicine, 73(7), 598. Link
Enck, P., Benedetti, F., & Schedlowski, M. (2008). New insights into the placebo and nocebo responses. Neuron, 59(2), 195-206. Link
Colloca, L., & Barsky, A. J. (2020). Placebo and nocebo effects. New England Journal of Medicine, 382(6), 554-561. Link
Colloca, L., & Finniss, D. (2012). Nocebo effects, patient-clinician communication, and therapeutic outcomes. Jama, 307(6), 567-568. Link
Amanzio, M., Howick, J., Bartoli, M., Cipriani, G. E., & Kong, J. (2020). How do nocebo phenomena provide a theoretical framework for the COVID-19 pandemic?. Frontiers in psychology, 2805. Link
Daniali, H., & Flaten, M. A. (2021). Experiencing COVID-19 symptoms without the disease: The role of nocebo in reporting of symptoms. Scandinavian Journal of Public Health, 14034948211018385. Link
Pachur, T., Hertwig, R., & Steinmann, F. (2012). How do people judge risks: availability heuristic, affect heuristic, or both?. Journal of Experimental Psychology: Applied, 18(3), 314. Link