Uptake, Safety and Attitudes Towards COVID-19 Vaccination: A Cross-Sectional Study on First and Second Doses Among the General Public

Objective

To investigate public uptake, attitudes and the safety of the first and second doses of COVID-19 vaccination.

Methods

This was a cross-sectional web-based survey study. A self-administered questionnaire was prepared from a literature search and information about COVID-19 available at various resources. The developed questionnaire was validated for readability by experts and refined in light of the feedback received from the experts and the final version was prepared. The reliability of the questionnaire was 0.7 which shows an acceptable level of scale internal consistency. The data analysis was performed using IBM SPSS software (version 25).

Results

A total of 513 participants completed the survey, including 311 (60.6%) women and 202 (39.4%) men. The mean age was (31.5±12.8) years. It was found that 493 (96.1%) took the first and second doses of COVID-19 and 376 (73.3%) suffered from side effects, of these 14% (56/376) reported the side effects to the health authorities. The most common side effects were fatigue (51.5%), fever (42.3%), headache (39.5%), and injection site pain (37.6%). Half of the participants (50.5%) had a positive attitude towards COVID-19 preventive measures. Females had higher odds of experiencing side effects than males OR (95% CI); 2.002 (1.312-3.056). Individuals living in urban areas had lower odds of experiencing side effects than those living in rural areas OR (95% CI); 0.364 (0.142-0.933).

Conclusion

Vaccine uptake was massive and side effects due to the COVID-19 vaccine were common but minor. The majority of the participants had positive attitudes towards recommended COVID-19 preventive measures. Being female and living in rural areas were associated with experiencing side effects.

Influence of Intrinsic Aerobic Exercise Capacity and Sex on Cardiac Injury Following Acute Myocardial Ischemia and Reperfusion

Purpose: Previous reports have suggested that active exercise aside, intrinsic aerobic running capacity (Low = LCR, high = HCR) in otherwise sedentary animals may influence several cardiovascular health-related indicators. Relative to the HCR phenotype, the LCR phenotype is characterized by decreased endothelial reactivity, increased susceptibility to reperfusion-induced arrhythmias following short, non-infarction ischemia, and increased diet-induced insulin resistance. More broadly, the LCR phenotype has come to be characterized as a "disease prone" model, with the HCRs as "disease resistant." Whether these effects extend to injury outcomes in an overt infarction or whether the effects are gender specific is not known. This study was designed to determine whether HCR/LCR phenotypic differences would be evident in injury responses to acute myocardial ischemia-reperfusion injury (AIR), measured as infarct size and to determine whether sex differences in infarction size were preserved with phenotypic selection. Methods: Regional myocardial AIR was induced in vivo by either 15 or 30 min ligation of the left anterior descending coronary artery, followed by 2 h of reperfusion. Global ischemia was induced in isolated hearts ex vivo using a Langendorff perfusion system and cessation of perfusion for either 15 or 30 min followed by 2 h of reperfusion. Infarct size was determined using 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and normalized to area at risk in the regional model, or whole heart in the global model. Portions of the tissue were paraffin embedded for H&E staining and histology analysis. Results: Phenotype dependent differences in infarct size were seen with 15 min occlusion/2 h reperfusion (LCR > HCR, p < 0.05) in both regional and global models. In both models, longer occlusion times (30 min/2 h) produced significantly larger infarctions in both phenotypes, but phenotypic differences were no longer present (LCR vs. HCR, p = n.s.). Sex differences in infarct size were present in each phenotype (LCR male > LCR female, p < 0.05; HCR male > HCR female, p < 0.05 regardless of length of occlusion, or ischemia model. Conclusions: There is cardioprotection afforded by high intrinsic aerobic capacity, but it is not infinite/continuous, and may be overcome with sufficient injury burden. Phenotypic selection based on endurance running capacity preserved sex differences in response to both short and longer term coronary occlusive challenges. Outcomes could not be associated with differences in system characteristics such as circulating inflammatory mediators or autonomic nervous system influences, as similar phenotypic injury patterns were seen in vivo, and in isolated crystalloid perfused heart ex vivo.

Low Intrinsic Aerobic Capacity Limits Recovery Response to Hindlimb Ischemia

Introduction: In this study, we determined the influence of intrinsic exercise capacity on the vascular adaptive responses to hind limb ischemia. High Capacity Running, HCR; Low Capacity Running, LCR, rats were used to assess intrinsic aerobic capacity effects on adaptive responses to ischemia.

Methods: Muscle samples from both ischemic and non-ischemic limb in both strains were compared, histologically for the muscle-capillary relationship, and functionally using microspheres to track blood flow and muscle stimulation to test fatigability. PCR was used to identify the differences in gene expression between the phenotypes following occlusive ischemia.

Results: Prior to ligation, there were not significant differences between the phenotypes in the exhaustion time with high frequency pacing. Following ligation, LCR decreased significantly in the exhaustion time compare with HCRs (437 ± 47 vs. 824 ± 56, p < 0.001). The immediate decrease in flow was significantly more severe in LCRs than HCRs (52.5 vs. 37.8%, p < 0.001). VEGF, eNOS, and ANG2 (but not ANG1) gene expression were decreased in LCRs vs. HCRs before occlusion, and increased significantly in LCRs 14D after occlusion, but not in HCRs. LCR capillary density (CD) was significantly lower at all time points after occlusion (LCR 7D = 564.76 ± 40.5, LCR 14D = 507.48 ± 54.2, both p < 0.05 vs. HCR for respective time point). NCAF increased significantly in HCR and LCR in response to ischemia.

Summary: These results suggest that LCR confers increased risk for ischemic injury and is subject to delayed and less effective adaptive response to ischemic stress.

Augmented Cardiac Mitochondrial Capacity in High Capacity Aerobic Running "Disease-Resistant" Phenotype at Rest Is Lost Following Ischemia Reperfusion

Rationale: Regular active exercise is considered therapeutic for cardiovascular disease, in part by increasing mitochondrial respiratory capacity, but a significant amount of exercise capacity is determined genetically. Animal models, demonstrating either high capacity aerobic running (HCR) or low capacity aerobic running (LCR) phenotypes, have been developed to study the intrinsic contribution, with HCR rats subsequently characterized as "disease resistant" and the LCRs as "disease prone." Enhanced cardioprotection in HCRs has been variable and mutifactoral, but likely includes a metabolic component. These studies were conducted to determine the influence of intrinsic aerobic phenotype on cardiac mitochondrial function before and after ischemia and reperfusion. Methods: A total of 34 HCR and LCR rats were obtained from the parent colony at the University of Toledo, housed under sedentary conditions, and fed normal chow. LCR and HCR animals were randomly assigned to either control or ischemia-reperfusion (IR). On each study day, one HCR/LCR pair was anesthetized, and hearts were rapidly excised. In IR animals, the hearts were immediately flushed with iced hyperkalemic, hyperosmotic, cardioplegia solution, and subjected to global hypothermic ischemic arrest (80 min). Following the arrest, the hearts underwent warm reperfusion (120 min) using a Langendorff perfusion system. Following reperfusion, the heart was weighed and the left ventricle (LV) was isolated. A midventricular ring was obtained to estimate infarction size [triphenyltetrazolium chloride (TTC)] and part of the remaining tissue (~150 mg) was transferred to a homogenation buffer on ice. Isolated mitochondria (MITO) samples were prepared and used to determine respiratory capacity under different metabolic conditions. In control animals, MITO were obtained and prepared similarly immediately following anesthesia and heart removal, but without IR. Results: In the control rats, both resting and maximally stimulated respiratory rates were higher (32 and 40%, respectively; p < 0.05) in HCR mitochondria compared to LCR. After IR, resting MITO respiratory rates were decreased to about 10% of control in both strains, and the augmented capacity in HCRs was absent. Maximally stimulated rates also were decreased more than 50% from control and were no longer different between phenotypes. Ca++ retention capacity and infarct size were not significantly different between HCR and LCR (49.2 ± 5.6 vs. 53.7 ± 4.9%), nor was average coronary flow during reperfusion or arrhythmogenesis. There was a significant loss of mitochondria following IR, which was coupled with decreased function in the remaining mitochondria in both strains. Conclusion: Cardiac mitochondrial capacity from HCR was significantly higher than LCR in the controls under each condition. After IR insult, the cardiac mitochondrial respiratory rates were similar between phenotypes, as was Ca++ retention capacity, infarct size, and arrhythmogenicity, despite the increased mitochondrial capacity in the HCRs before ischemia. Relatively, the loss of respiratory capacity was actually greater in HCR than LCR. These data could suggest limits in the extent to which the HCR phenotype might be "protective" against acute tissue stressors. The extent to which any of these deficits could be "rescued" by adding an active exercise component to the intrinsic phenotype is unknown.

Oral Feeding of Probiotic Bifidobacterium infantis: Colonic Morphological Changes in Rat Model of TNBS-Induced Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology. It has been proposed that modifying the bacterial flora in intestine with probiotics may decrease the inflammatory process and prevent relapses in UC. We investigated the possible protective and therapeutic effects of a single strand of probiotic, Bifidobacterium infantis (BI), on colonic inflammation, in rats with regular feedings. Two groups of Lewis rats were prepared (n = 8). The first group was the control, sham-fed group (n = 4). The other group was the experimental BI-fed group (n = 4). Colitis was induced in both groups by intrarectal administration of TNBS under light anesthesia. The sham-fed colitis induced groups received a daily oral gavage feeding of 1.0 mL distilled water, whereas the B. infantis-fed group received 0.205 g of B. infantis dissolved in 1.0 mL distilled water daily. The change in body weight and food and water intake was recorded over the course of each study and analyzed. The rats were euthanized and tissues from the descending colon were harvested and analyzed microscopically and histologically. Results of our study indicated significant reduction in inflammation, mucosal damage, and preservation of goblet cells, as compared to the control animals. Modulation of gastrointestinal (GI) flora suggests a promising field in developing strategies for prevention and treatment of inflammatory bowel diseases by dietary modifications.