Our CARTOON program, an interdisciplinary psychoeducational intervention, unfolds over five instructive sessions, each addressing key aspects of hygiene and COVID-19 awareness (Supplementary Material) (16). These sessions cover topics such as hand hygiene, facial contact avoidance, sneezing etiquette, mask-wearing, and social distancing. To make the learning experience engaging and child-friendly, we utilize specialized exercises and games. For ease of accessibility, the full English translation of our CARTOON program is provided in the Supplementary Material.

Our program introduces the “CCP heroes” (Supplementary Material). These heroes, namely Captain Soapy Hands, Mister Sneeze, Do not Touch Tina, Flying Mask-up Mona, and Hero of the Distance, are depicted in a comic style designed by Dr. Philipp Steinbauer at the Comprehensive Center for Pediatrics (CCP) of the Medical University of Vienna. The CCP heroes effectively convey fundamental rules to prevent the spread of SARS-CoV-2. Posters featuring these self-designed heroes were prominently displayed in the kindergarten environment, serving as regular reminders for children to adhere to hygiene measures.

Moreover, our psychoeducational program spanned five days, with each daily session lasting 60 min. Conducted in groups of up to six children, the sessions were facilitated by trained staff members, ensuring an interactive and informative learning experience. To minimize response bias, interviewers were trained to use neutral phrasing, avoid leading questions, and ensure a comfortable, non-judgmental environment. Visual aids (such as illustrations) were incorporated to support understanding. Additionally, children were encouraged to provide their own answers without external influence from peers or caregivers. Participant adherence to the program was monitored throughout the intervention. Attendance records were maintained for each session, and completion rates were assessed at the end of the program. There were no additional drop-out rates during the study period.

Descriptive statistics were used to summarize baseline characteristics of recruited participants. In order to test differences between the two groups with regard to theoretical and practical knowledge, as well as emotion t-tests for independent samples were performed.

Categorical variables are in absolute frequencies and percentages. Continuous variables are listed in means and standard deviations and were presented in tables. For the analysis of covariates to predict knowledge regarding COVD-19 and hygiene measures a linear regression model was performed. The following covariates were included: age, gender, education of mother, number of children in the household, cramped living conditions, and mental stress in the family. Statistical analysis was performed using SPSS 24 (IBM Corporation, Armonk, NY, USA). A p-value of < 0.05 was considered as statistically significant.

Fifty-three children completed the baseline assessment including the corona quiz and the assessment of anxiety (Table 3). There were no significant differences between the control and intervention group when comparing the means of theoretical knowledge about COVID-19 (4.1 ± 2.3 vs. 3.9 ± 2.4; p = .76) and hygiene knowledge (6.3 ± 2.3 vs. 5.9 ± 2.3; p = .53) at baseline. Moreover, we did not find a difference between the control and intervention group regarding overall anxiety (1.3 ± 2.9 vs. 1.1 ± 1.7; p = .77) and anxiety regarding COVID-19 (5.1 ± 3.8 vs. 5.6 ± 2.5; p = .57) at baseline. However, when comparing overall anxiety with anxiety regarding COVID-19 within the groups there was a statistically significant difference in both groups (control group: 1.3 ± 2.9 vs. 5.1 ± 3.8, p = .01; intervention group: 1.1 ± 1.7 vs. 5.6 ± 2.5, p < .01) (Table 3).

Fifty-three children completed the short-term assessment (Table 3). There were no significant differences when comparing the baseline knowledge about COVID-19 with the short-term knowledge about COVID-19 within the control group (4.1 ± 2.3 vs. 4.0 ± 1.9; p = .86) as well as the intervention group (3.9 ± 2.4 vs. 4.6 ± 1.9; p = .27). When comparing the baseline knowledge about hygiene measures with the short-term knowledge about hygiene measures, no significant differences within the control (6.3 ± 2.3 vs. 6.2 ± 2.0; p = .86) and intervention group (5.9 ± 2.3 vs. 6.3 ± 2.6; p = .58) were found.

Participants in the intervention group exhibited significantly lower anxiety scores after the short-term assessment when compared with the baseline assessment (2.2 ± 1.7 vs. 5.6 ± 2.5; p = .01). However, there was no significant difference within the control group when comparing the baseline scores of COVID-19 related anxiety with short-term scores (5.1 ± 3.8 vs. 4.9 ± 3.1; p = .39) (Table 3).

Fifty-three children completed the long-term assessment (Table 3). Control group children showed no significant differences in knowledge about COVID-19 when comparing the baseline with the long-term assessment scores (4.1 ± 2.3 vs. 4.4 ± 2.0, p = .60). However, children assigned to the intervention group showed an increase in knowledge about COVID-19 when comparing baseline and short term scores (3.9 ± 2.4 vs. 5.9 ± 2.0, p = .003).

There were no significant differences in knowledge about hygiene measures when comparing the baseline (6.3 ± 2.3) with the long-term assessment scores (6.7 ± 2.3; p = .51). However, children included in the intervention group showed significantly better knowledge about hygiene measures in the long-term assessment when compared to the baseline assessment scores (7.2 ± 2.2 vs. 5.9 ± 2.3, <0.001).

Results of multivariable linear regression analysis of risk factors to predict knowledge scores about COVID-19 and hygiene measures are provided in Table 4. Lower age of the children and lower education of the mother were both significantly predictive for lower knowledge regarding COVID-19 and hygiene measures in children. In addition, mental stress in the family was also associated with lower knowledge regarding COVID-19 and hygiene measures (Table 4).

To the best of our knowledge, there is currently only one cartoon-based educational program on hygiene measures for children. However, it is important to note that that program, named “The Magic Glasses,” does not function as an educational intervention against COVID-19. Instead, it serves as a hygiene education intervention package specifically designed to prevent worm infections in Chinese schoolchildren (28). In contrast, the CARTOON program effectively conveys fundamental rules to prevent the spread of SARS-CoV-2, and could be easily adapted to other situations associated with the spread of respiratory pathogens, showing propensity to generalizability. CARTOON has demonstrated a significant enhancement in knowledge about COVID-19 and adherence to preventive measures three months post-intervention. This suggests its potential as a valuable tool for future pandemics. By employing child-friendly teaching methods and engaging visuals, we effectively communicated information to preschool children, facilitating a deeper understanding of knowledge and preventive measures. Despite the notable impact of our educational program on knowledge, the regression model highlights two key factors that warrant further consideration. Specifically, the age of the participant and maternal education emerged as particularly influential in the process of knowledge acquisition. In fact, children's ability to form a real representation of important life events develops gradually. Around the ages 3–5, children start to understand basic concepts, but a more nuanced understanding typically develops between the ages 7–10 (29, 30). As children grow and their cognitive abilities mature, they progress from concrete thinking, which is focused on tangible, observable things, to abstract thinking, which involves understanding symbols, metaphors, as well as hypothetical, and more complex situations. Abstract thinking strongly relates to the maturation of cognitive abilities, the latter particularly mediated by surrounding factors such as maternal education (30). Maternal education, in particular, has been found to have a significant impact on various aspects of children's knowledge acquisition and overall development, including: cognitive development, language development, educational attainment, social and emotional behavior, and nutrition (31–33).

Usually, knowledge can have a significant impact on psychic well-being in various ways. When individuals have clear, reliable knowledge about a situation, they are better equipped to understand potential risks and develop effective coping strategies. Ambiguity and uncertainty, on the other hand, can contribute to heightened anxiety. The same is true in the context of health care and crisis situations (34–36).

The COVID-19 pandemic has not only posed significant physical health risks but has also had a substantial impact on the mental well-being of individuals, including children.

Importantly, our CARTOON intervention not only focused on knowledge acquisition but also addressed children's emotional well-being. Participants in the intervention group experienced a significant reduction in anxiety scores related to COVID-19, whereas the control group did not show significant changes. This finding suggests that CARTOON not only provided children with knowledge but also helped alleviate their fears and anxiety surrounding the pandemic. Interestingly, higher levels of COVID-19-related knowledge and knowledge about preventive measures were associated with reduced emotional and behavioral problems in children in a study by Wang and colleagues (37). This is also in line with a study by Zhou and colleagues who showed a high prevalence of psychological health problems among adolescents, which were negatively associated with the level of knowledge about COVID-19 (5). By using child-friendly illustrated pictures and engaging teaching sessions, we created an environment where children felt empowered and equipped to cope with the challenges posed by the virus.

Our study has several limitations. First, our sample size was relatively small, which may limit the generalizability of the findings. Although the results demonstrate significant improvements in hygiene knowledge and anxiety reduction, larger-scale studies are required to validate these effects in broader populations. Additionally, the study only included a three-month follow-up, making it difficult to assess the long-term retention of knowledge and behavior change.

Second, the study was conducted in two kindergartens in Vienna, Austria. The specific cultural and educational context may influence the results, and the findings might differ in other settings or different countries with variations in educational systems, and cultural differences in health education approaches. Third, the emotional scales and quizzes, while adapted for children, may still have limitations in accurately capturing the full range of emotions and knowledge in young children. However, we have used only validated tools in order to minimize this bias.

Another potential limitation of this study is the possibility of response bias in children's interviews. Due to their developmental stage, young children may interpret questions differently, provide socially desirable answers, or be influenced by the interviewer's phrasing or demeanor. While efforts were made to minimize these biases through structured interview techniques, neutral questioning, and the use of visual aids, the possibility of misinterpretation or response distortion cannot be entirely ruled out.

In addition, other factors, such as prior exposure to hygiene education or parental attitudes toward hygiene, may also play a role in shaping children's knowledge and responses to the intervention. Since these data were not collected in this study, their potential influence on the results remains unknown.