Page 112 - JCBP-3-1

Journal of Clinical and
Basic Psychosomatics Concerns about COVID-19 vaccination and AE rate

regarding the vaccination process and the AE rate, which process and higher AE prevalence. We could not prove
is consistent with previous data. 6-9 causality. The pharmacovigilance behavior of our
Concerns regarding the (unknown) side effects participants with an intensive AE registration could also
of vaccinations can cause vaccination skepticism and have resulted in the higher AE rate. Nonetheless, regardless
refusal. 16,26,27 The significant association between concern of the cause of increased AE rates, the underlying
and increased rate of side effects may be explained by self- mechanism should be seriously considered and possible
fulfilling prophecy. 28,29 Negative expectations promote countermeasures should be initiated. Although studies
the emergence of feared and even unlikely developments into nocebo effects have recently increased, little is known
in the future, among other things, by reinforcing certain about the influencing factors and measures to reduce
10,22,23
predisposing behaviors. Pagnini et al. demonstrated that them. However, further studies are required to identify
the expectation of colds in the summer is significantly nocebo effects in clinical (e.g., RCTs) and observational
associated with the development of flu-like symptoms in (i.e., studies without a placebo group) studies. For example,
30
the winter. They cited so-called nocebo effects, which are sex- and gender-related expectations of vaccines as
initiated by negative expectations, among other things, well as knowledge about health beliefs before a medical
as a possible explanation for this association. However, intervention (e.g., vaccination, drug therapy) may be
determining these effects directly in non-interventional examined. Subsequently, measures to reduce nocebo effects
studies is not possible. Thus, the exact underlying should be investigated and their effectiveness in clinical and
mechanism remains unclear. However, increased self- observational studies should be examined. These results
attention might have a reinforcing effect. People who could help implement individual and population-based
31
are worried about the vaccination course may be more measures for personalized medicine and prevention.
concerned about the possible side effects than those who 5. Conclusion
are not worried. Furthermore, participants who want to
accurately document their AEs (e.g., for pharmacovigilance) Nocebo-like effects might have played a role in the
may experience more AEs because they specifically pay AEs developed in our sample. Since high AE rates can
attention to the expected side effects. 14,26,29 contribute to vaccine hesitancy, as much as possible should
be done to minimize nocebo effects.
There are recommendations to reduce nocebo
effects. These recommendations are partially aimed at Acknowledgments
reducing self-awareness by providing less information
on insignificant side effects after counseling the patients The authors would like to thank Sabine Kohler for
regarding the nocebo phenomenon and obtaining their formatting the questionnaires and assisting in the creation
consent. This prior consent is necessary to safeguard the of the Excel database; Romana Galczak, Sabine Kohler,
9
patients’ rights. Drawing attention to an unknown side and Gabriele Kamakaris for distributing and collecting
effect is impossible. Whereas it is very difficult not to think the questionnaires; Filiz Meseli for legal support in data
about something that was previously announced. Providing protection and personnel law issues; the staff council,
focused information in observational studies would which reviewed this study in detail within a very short
benefit pharmacovigilance because regardless of the reason time before Christmas 2020 and approved it in good time;
for increased attention to expected side effects, a more the board, which agreed that the study was displayed in
objective reporting would be possible. Accordingly, we the vaccination centers; and especially all colleagues at the
consider it unlikely that particularly detailed information hospital who participated in this study in large numbers.
on side effects, as suggested by some authors, would reduce Funding
fears and negative expectations, respectively. 1,11,21
None.
A limitation of our study is the use of real-world data
in an observational setting. Clear evidence of nocebo Conflict of interest
effects cannot be obtained in this setting. In principle,
our study participants may have had a positive attitude The authors declare that they have no competing interests.
toward vaccination, resulting in lesser nocebo effects than Author contributions
that in the normal population. However, our survey
16
included medical professionals from different fields. Conceptualization: Isabel Hach, Stephan Kolb
Thus, vaccination expectations and knowledge regarding Formal analysis: Isabel Hach, Bunila-Yuwang Francisca,
vaccinations may differ. We could only demonstrate the Wolfgang Hitzl
association between concerns regarding the vaccination Investigation: Isabel Hach

Volume 3 Issue 1 (2025) 106 doi: 10.36922/jcbp.4727