Oral Side Effects of COVID-19 Vaccine

The primary objective of this multicentre cross-sectional survey-based study is to estimate
the prevalence of oral side effects of COVID-19 vaccine in the short term.

The secondary objectives are:

- to identify the risk factors of COVID-19 vaccine oral side effects in the short term.

- to evaluate the relationship between oral side effects and other inflammatory side
effects of COVID-19 vaccine in the short term.

The target population is healthcare workers as they are identified among the priority groups
of COVID-19 vaccine deployment plans in the EU/EEA and the UK. One more reason to select the
healthcare workers among different groups of the population, their higher awareness about the
possible vaccine-related oral side-effects so that more accurate and reliable results can be
obtained.

A self-administered questionnaire will be developed, and its content validity will be tested
using a panel of experts. The test re-test reliability of the questionnaire will be tested by
30 volunteers (10 Czech, 10 Turkish, 10 German) to achieve at least a Cronbach's alpha of
0.70. The questionnaire will be available in five languages; Czech, English, German, Slovak
and Turkish. Dual forward translation and expert panels will produce equivalent Czech,
German, Slovak and Turkish versions of the questionnaire.

The questionnaire will be composed of multiple-choice items divided into four main
categories; a) demographic data including gender, age, location of practice, profession, and
experience, b) medical anamnesis including medical comorbidities, medications, and recent
oral symptoms, c) COVID-19 related anamnesis including vaccination date, previous infection,
and exposure to infected cases, and d) vaccine side effects including inflammatory symptoms,
cutaneous symptoms, and oral symptoms. (Annex 1)