Background: Porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHP) are economically significant pathogens in the pig industry. The use of combined vaccines against PCV2 and MHP is one of the most effective ways of protecting pigs from both diseases, and it has become a part of general management. Objectives: This study evaluated the efficacy of two new bivalent vaccines of PCV2 and MHP (Myco-X and Myco-XD) in SPF pigs. Myco-X and Myco-XD are a combined vaccine of MHP with PCV2b and PCV2d, respectively. Methods: Sixteen pigs were divided into four groups: Myco-X-vaccinated challenged, Myco-XD-vaccinated challenged, unvaccinated challenged, and unvaccinated unchallenged.Two milliliters of Myco-X were administered intramuscularly, and 0.5 mL of Myco-XD was injected intradermally at 3 wk of age. The pigs were challenged with virulent PCV2d via the intramuscular and intranasal route 4 wk post-vaccination. Results: All vaccinated pigs showed effective reduction of the clinical signs, the PCV2d load in the blood and nasal swab samples, as well as lung and lymphoid tissue lesions in the challenge test. Compared to unvaccinated challenged animals, the vaccinated challenged animals showed significantly higher (p < 0.05) levels of anti-PCV2 IgG, PCV2d-specific interferon-γ (IFN-γ), and anti-MHP IgG. Conclusions Based on clinical, microbiological, serological, and pathological assessments, this study confirmed that both combined vaccines could protect pigs against PCV2 infection caused by PCV2d. On the other hand, further research on the efficacy evaluation of these new vaccines against the MHP challenge and PCV2d/MHP co-challenge is needed.

This study examined the relationships among personality traits, coping efficacy, and academic stress in medical and non-medical students in South Korea, and investigated the mediating effect of coping efficacy in the relationship between personality traits and academic stress. The study group comprised 210 medical students and 175 non-medical students. They were asked to rate their personality traits, coping efficacy, and academic stress. The data were analyzed using IBM SPSS ver. 26.0 (IBM Corp., Armonk, NY, USA) and AMOS ver. 26.0 (IBM Corp.). Medical students scored higher for examination stress and lower for extroversion than non-medical students. In both groups, extroversion and conscientiousness positively affected coping efficacy, while neuroticism influenced it negatively. Neuroticism directly influenced all types of academic stress in both groups, while extroversion and conscientiousness only had direct effects on examination stress among medical students. Coping efficacy mediated the associations between personality traits and academic stress, except for the relationship between neuroticism and grade stress among medical students. The study indicates that coping efficacy had a significant effect on relieving academic stress among students with higher scores for extroversion and conscientiousness. Efforts should be made to decrease neuroticism to lower academic stress, as the relationship between neuroticism and academic stress is not directly influenced by coping efficacy. The implications of these results are discussed regarding a consultation system for students, especially those in medical school.

This study examined the relationships among personality traits, coping efficacy, and academic stress in medical and non-medical students in South Korea, and investigated the mediating effect of coping efficacy in the relationship between personality traits and academic stress. The study group comprised 210 medical students and 175 non-medical students. They were asked to rate their personality traits, coping efficacy, and academic stress. The data were analyzed using IBM SPSS ver. 26.0 (IBM Corp., Armonk, NY, USA) and AMOS ver. 26.0 (IBM Corp.). Medical students scored higher for examination stress and lower for extroversion than non-medical students. In both groups, extroversion and conscientiousness positively affected coping efficacy, while neuroticism influenced it negatively. Neuroticism directly influenced all types of academic stress in both groups, while extroversion and conscientiousness only had direct effects on examination stress among medical students. Coping efficacy mediated the associations between personality traits and academic stress, except for the relationship between neuroticism and grade stress among medical students. The study indicates that coping efficacy had a significant effect on relieving academic stress among students with higher scores for extroversion and conscientiousness. Efforts should be made to decrease neuroticism to lower academic stress, as the relationship between neuroticism and academic stress is not directly influenced by coping efficacy. The implications of these results are discussed regarding a consultation system for students, especially those in medical school.