Vaccines are an important tool of preventive medicine. Organized vaccination programs have saved numerous people from serious infectious diseases. Surprisingly, there is a considerable portion of the population who oppose vaccinations. In particular, the existence of anti-vaccination perceptions among travelers to countries with endemic diseases is a major public health concern. Although hesitancy towards vaccinations is not a novel phenomenon, it came back to the forefront during the fight against the COVID-19 pandemic. This review explored the etiology of anti-vaccination beliefs among travelers and drew conclusions about their impact on public health and society in general. For this purpose, a purposeful search for data on the causative factors of vaccine hesitancy and their impact on people’s health was conducted. A descriptive analysis of the findings and conclusions about possible implications in health policy and clinical practice are presented. Fear of side effects, lack of credence in the necessity of vaccines, and mistrust of medical authorities are important causative factors. Their interplay shapes hesitancy towards vaccines. However, anti-vaccination beliefs can also be an aspect of a more general unconventional stance of life. Health care professionals and organizations must be ready to tackle vaccine hesitancy by making the necessary interventions. Correcting misconceptions about vaccinations is a prerequisite for ensuring personal and public health, especially in the context of a pandemic or epidemic. Moreover, ensuring the efficacy and safety of vaccines, especially in cases of modern technology applications, is a fundamental factor in addressing people’s concerns about vaccines. For this purpose, medical authorities and organizations must provide accurate and clear information on vaccines so as to eliminate misinformation. Furthermore, clinicians should cultivate their communication skills in order to convey the appropriate messages to prospective recipients of vaccinations.

During the pandemic, nurses experienced anger that stemmed from a sense of threat, frustration or even a sense of injustice. The purpose of this study was to examine the relationship between vaccination hesitancy, anger, cynicism and medical mistrust among nurses, as there are no relevant studies in the literature. The study was conducted online by completing self-report questionnaires. The Dimensions of Anger Reactions-5, the 8-item "Cynical Distrust" scale and the Medical Mistrust Multiformat Scale were used. For vaccination hesitancy, two questions with a 5-point scale were used; one question examining hesitancy to get vaccinated with the COVID-19 vaccine, and another question examining hesitancy to get vaccinated with the influenza vaccine. 387 nurses (66 men and 321 women) participated in the study. Nurses showed statistically greater hesitancy for the COVID-19 vaccine compared to hesitancy for the influenza vaccine. The variation in Vaccine Hesitancy was explained by the scores in the Medical Mistrust Multiformat Scale, the Dimensions of Anger Reactions and the Cynical Distrust Scale. The Medical Mistrust Multiformat Scale mediated the relationship between Cynical Distrust Scale and Total Vaccine Hesitancy. The Dimensions of Anger Reactions Scale significantly moderated the indirect effect of Cynical Distrust Scale on Total Vaccine Hesitancy through the Medical Mistrust Multiformat Scale. In conclusion, it is highly likely that anger is involved in reported vaccine hesitancy both by activating schemas of distrust in others and by adopting antisystemic views of mistrust in the medical system.

Introduction/Aim: Central sensitivity to thyroid hormones refers to the sensitivity of the hypothalamic-pituitary-thyroid (HPT) axis to changes in circulating free thyroxine (fT4). The relationship between fT4 levels and iodine intake is complex. The aim of the present study was to assess central sensitivity to thyroid hormones in pregnancy against iodine intake. Materials & Methods: One thousand one hundred two blood and urine samples were collected from pregnant women (with a mean age+SD of 30.4+4.6 years) during singleton pregnancies; women with known/diagnosed thyroid disease were excluded. Specifically, TSH & fT4 and 24-hour urinary iodine excretion (UI) were measured in each trimester and at two months postpartum. The Thyroid Feedback Quantile-based Index (TFQI) was calculated to assess central sensitivity to thyroid hormones. For the statistical analysis of TFQI by time period, analysis of variance (ANOVA) was used, while Pearson's correlation was used to assess TFQI versus UI. Results: The mean TFQI index ranged from -0.06 (first trimester) to -0.07 (two months postpartum), while the corresponding UI was 141 and 172 μg/L, respectively. The TFQI-UI correlation was negative (Pearson r: -0.325, p: 0.04 and r: -0.399, p: 0.023), for UI values over 250 μg/L, in the first and the third trimester of pregnancy, respectively. Discussion: TFQI is a new index reflecting central sensitivity to thyroid hormones. Lower TFQI indicates higher sensitivity to thyroid hormones. In our sample TFQI was inversely related to iodine intake, in the first trimester of pregnancy (the critical period of organogenesis) and the third trimester (the critical period of fetal growth). Thus, the observed changes in TFQI may reflect different ways of central action of thyroid hormones, according to the phase of pregnancy. The negative association between maternal TFQI (indicative of central sensitivity to thyroid hormone) and urine iodine levels during the third trimester of pregnancy may reflect the combined influence of maternal and fetal thyroid function. Our results are intriguing and have the potential to enhance our comprehension of the changes in the HPT axis’ function via variations in central sensitivity to thyroid hormones and its interplay with nutritional iodine status during pregnancy.