Pneumococcal carriage and changes in serotype distribution post- PCV13 introduction in children in Matiari, Pakistan.

BACKGROUND: In early 2021, the 10-valent Pneumococcal conjugate vaccine (PCV10) was replaced with 13-valent (PCV13) by the federal directorate of immunization (FDI), Pakistan. We assessed the impact of a higher valent vaccine, PCV13, on the serotype distribution of nasopharyngeal carriage in rural Pakistan. METHODS: Children <2 years were randomly selected from two rural union councils of Matiari, Sindh in Pakistan between September-October,2022. Clinical, sociodemographic and vaccination histories were recorded. Nasopharyngeal swabs were collected and processed at Infectious Disease Research Laboratory, Aga Khan University, Karachi. Whole genome sequencing was performed on the culture positive isolates. RESULTS: Of the 200 children enrolled, pneumococcus was detected in 140(70 %) isolates. Majority of age-eligible children (60.1 %,110/183) received 3 PCV13 doses. PCV10 carriage declined from 13.2 %(78/590) in 2017/18 to 7.2 % (10/140) in 2022, additional PCV13 serotypes (3, 6A/6C and 19A) decreased from 18.5 %(109/590) to 11.4 %(16/140) while non-PCV13 serotypes increased from 68.3 %(403/590) to 81.4 %(114/140). There were 88.5 %(n = 124), 80.7 %(n = 113), 55.0 %(n = 77), and 46.0 %(n = 65) isolates predicted to be resistant to cotrimoxazole, penicillin(meningitis cut-off), tetracycline, and erythromycin respectively. CONCLUSION: Replacing PCV10 with PCV13 rapidly decreased prevalence of PCV13 carriage among vaccinated children in Matiari, Pakistan. Vaccine-driven selection pressure may have been responsible for the increase of non-PCV13 serotypes.

Use of Myo-Inositol Vaginal Pessary in the Treatment of Subfertility.

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Does the implementation of revised American College of Cardiology and American Heart Association (ACC/AHA) guidelines improve the identification of stillbirths and preterm births in hypertensive pregnancies: a population-based cohort study from South Asia and sub-Saharan Africa.

BACKGROUND: Hypertensive disorders of pregnancy (HDP) are a significant cause of maternal mortality worldwide. The classification and treatment of hypertension in pregnancy remain debated. We aim to compare the effectiveness of the revised 2017 ACC/AHA blood pressure threshold in predicting adverse pregnancy outcomes. METHODS: We conducted a secondary data analysis of the Alliance for Maternal and Newborn Health Improvement (AMANHI) biorepository study, including 10,001 pregnant women from Bangladesh, Pakistan, and Tanzania. Blood pressure was measured using validated devices at different antenatal care visits. The blood pressure readings were categorized as: normal blood pressure (systolic blood pressure (sBP) < 120 mm Hg and diastolic blood pressure (dBP) < 80 mm Hg), elevated blood pressure (sBP 120-129 and dBP < 80), stage 1 hypertension (sBP 130-139 or dBP 80-89, or both), and stage 2 hypertension (sBP ≥ 140 or dBP ≥ 90, or both). We estimated risk ratios for stillbirths and preterm births, as well as diagnostic test properties of both the pre-existing JNC7 (≥ 140/90) and revised ACC/AHA (≥ 130/80) thresholds using normal blood pressure as reference group. RESULTS: From May 2014 to June 2018, blood pressure readings were available for 9,448 women (2,894 in Bangladesh, 2,303 in Pakistan, and 4,251 in Tanzania). We observed normal blood pressure in 70%, elevated blood pressure in 12.4%, stage 1 hypertension in 15.2%, and stage 2 hypertension in 2.5% of the pregnant women respectively. Out of these, 310 stillbirths and 9,109 live births were recorded, with 887 preterm births. Using the ACC/AHA criteria, the stage 1 hypertension cut-off revealed 15.3% additional hypertension diagnoses as compared to JNC7 criteria. ACC/AHA defined hypertension was significantly associated with stillbirths (RR 1.8, 95% CI 1.4, 2.3). The JNC 7 hypertension cut-off of ≥ 140/90 was significantly associated with a higher risk of preterm births (RR 1.6, 95% CI 1.2, 2.2) and stillbirths (RR 3.6, 95% CI 2.5, 5.3). Both criteria demonstrated low sensitivities (8.4 for JNC-7 and 28.1 for ACC/AHA) and positive predictive values (11.0 for JNC7 and 5.2 for ACC/AHA) in predicting adverse outcomes. CONCLUSION: The ACC/AHA criteria (≥ 130/80) identified additional cases of hypertension but had limited predictive accuracy for stillbirths and preterm births, highlighting the ongoing need for improved criteria in managing pregnancy-related hypertension.

Controlling Triboelectric Charge of MOFs by Leveraging Ligands Chemistry.

Metal-organic frameworks (MOFs) have emerged as promising materials for triboelectric nanogenerators (TENGs), but the effects of ligand choice on triboelectric charge remain underexplored. Hence, this paper demonstrates the effect of single, binary, and ternary ligands on TENG performance of cobalt/cerium-based (Co─Ce) bimetallic MOFs utilizing 2-methylimidazole (2Melm), terephthalic acid (BDC), and benzene tricarboxylic acid (BTC) as ligands. The detailed structural characterization revealed that varying ligand chemistries led to distinct MOF features affecting TENG performance. Single ligand bimetallic MOFs (designated as CoCe-2MeIm, CoCe-BDC, CoCe-BTC) has lower performance than binary ligand (designated as CoCe-2MeIm-BDC, CoCe-2MeIm-BTC, CoCe-BDC-BTC) and ternary ligand MOFs (designated as CoCe-2MeIm-BDC-BTC). Among all, the binary ligand MOF, CoCe-2MeIm-BTC, shows the best results (598 V, 26.7 µA) due to the combined effect of imidazole ring and (─COO─) groups. This is attributed to lone pairs on nitrogen atoms and a delocalized π-electron system in imidazole system in this material. CoCe-BTC has the lowest results (31 V, 3.2 µA) due to the bulkier nature of the electron-withdrawing (─COO─) groups and their impact on the π-electron system of the benzene ring. This study showcases the potential of ligand chemistry manipulation to control triboelectric charge and thereby enhance MOF-based TENG performance.

Assessing knowledge of dental house officers regarding dosage calculation and complications of local anaesthesia, in three tertiary care dental hospitals of DUHS, Karachi.

Objectives: To assess the knowledge and awareness of dental house officers regarding calculation of local anaesthesia dosage, and to evaluate differences in practices at various tertiary care facilities. METHODS: The cross-sectional study was conducted at three dental hospitals affiliated with Dow University of Health Sciences, Karachi from July to December 2022, and comprised house officers of either gender currently enrolled at the participating centres. Data was collected using a self-administered questionnaire to assess knowledge and awareness of local anaesthesia dosage calculation, administration methods, and common complications. Data was analysed using SPSS 26. RESULTS: Of the 200 subjects approached, 136(68%) responded, and 89(65.4%) of them were females. Knowledge regarding the meaning of 2% lidocaine solution was low 45(33%), and 68(50%) subjects were knowledgeable about the maximum dosage of lidocaine with epinephrine. In terms of practice, lidocaine was the most commonly administered local anaesthetic 115(85%), followed by bupivacaine 15(11%). The majority of subjects administered local anaesthesia with vasoconstrictor 127(94%), but only 36(27%) performed aspiration during administration. Syncope 71(52%) was the most commonly reported complication, followed by lip/cheek/tongue biting by 35(26%). CONCLUSIONS: House officers' knowledge level of local anaesthesia administration indicated the need for adequate training.

Incidental Finding of Atrial Myxoma in a Patient Presenting With Transient Ischemic Attack (TIA): A Case Report.

Atrial myxomas are benign primary cardiac tumors. They can present with nonspecific symptoms, ranging from constitutional symptoms and embolic phenomena such as transient ischemic attacks (TIAs) or strokes to sudden cardiac death. Early diagnosis may be a challenge due to the nonspecific presentation of atrial myxoma. A high degree of suspicion is needed in patients with TIA having no known cardiovascular risk factors. Although benign, if left untreated, it can lead to serious complications ranging from embolic phenomena and obstructive symptoms to sudden cardiac death. An echocardiogram is of fundamental importance in diagnosing atrial myxoma, and surgical resection is the ultimate treatment of choice. Here, we discuss a case of TIA as the initial presentation of atrial myxoma.

Role of rotavirus vaccine in reducing diarrheal episodes in infants visiting private primary health care clinics in Karachi, Pakistan: A mixed-methods study.

BACKGROUND: Rotavirus (RV) induced diarrhea led to hospitalization and mortality prior to the introduction of the rotavirus vaccine (RVV). The estimated RVV coverage was 86% in children less than one year of age in Pakistan. OBJECTIVES: To determine the difference in the number of diarrheal episodes among children who received and who did not receive RVV, along with the parental and physician's perspectives on the barriers toward RV immunization in children aged less than 1 year in Karachi, Pakistan. METHODS: A mixed-methods study design was conducted in three Primary Healthcare (PHC) private clinics located in different districts of Karachi, Pakistan. Data for RVV status and diarrheal episodes were collected, from medical records in June 2020 for children born between October 2019 to March 2020. Three In-depth Interviews (IDIs) with physicians and three focus group discussions (FGDs) with mothers were conducted for information on awareness and approach towards diarrhea, knowledge, and acceptance of RVV, and barriers towards RV immunization. RESULTS: A total of 430 infants visited the three PHC centres coded as A (n = 144), B (n = 146), and C (n = 140). The mean age of infants was 2.6 ± 0.2 months, 49.5 % were males and 87 (20.2 %) were partial/not vaccinated for RV. Reported diarrheal episodes were 104 (24.2 %), and of these 76 (73.1 %) were partially or not vaccinated, and 83 (79.8 %) were stunted. Recorded diarrhea was significantly associated with partial/not vaccinated status (p < 0.001), stunting (p < 0.001), and by PHC centre location (p < 0.001). PHC-C had the lowest percentage of reported diarrhea, stunting, and non/partially vaccinated status. Qualitative study (FGDs) showed that mothers had lack of awareness and knowledge on the prevention of diarrhea by RVV. Physicians' IDIs pointed towards a lack of sufficient training on RVV. CONCLUSION: Diarrheal episodes in infants were associated with partial or unvaccinated for RVV, low nutritional status, and areas of residence. Low levels of knowledge and awareness in caretakers and lack of training for RVV in PHC physicians were perceived as barriers in controlling diarrheal diseases.

Predictors of Respiratory Syncytial Virus, Influenza Virus, and Human Metapneumovirus Carriage in Children Under 5 Years With WHO-Defined Fast-Breathing Pneumonia in Pakistan.

BACKGROUND: Pneumonia is a leading cause of morbidity and mortality in children < 5 years. We describe nasopharyngeal carriage of respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza virus among children with fast-breathing pneumonia in Karachi, Pakistan. METHODS: We performed a cross-sectional analysis of nasopharyngeal swabs from children aged 2-59 months with fast-breathing pneumonia, enrolled in the randomized trial of amoxicillin versus placebo for fast-breathing pneumonia (RETAPP) (NCT02372461) from 2014 to 2016. Swabs were collected using WHO standardized methods, processed at the Aga Khan University, Pakistan. Viral detection was performed using LUMINEX xTAG respiratory viral panel assay and logistic regression identified clinical and sociodemographic predictors. FINDINGS: Of the 1000 children tested, 92.2% (n = 922) were positive for viral carriage. RSV, hMPV, and influenza virus were detected in 59 (6.4%), 56 (6.1%), and 58 (6.3%) children and co-infections in three samples (two RSV-hMPV and one influenza-hMPV). RSV carriage was common in infants (56%), we observed a higher occurrence of fever in children with hMPV and influenza virus (80% and 88%, respectively) and fast breathing in RSV (80%) carriage. RSV carriage was positively associated with a history of fast/difficulty breathing (aOR: 1.96, 95% CI 1.02-3.76) and low oxygen saturation (aOR: 2.52, 95% CI 1.32-4.82), hMPV carriage was positively associated with a complete vaccination status (aOR: 2.22, 95% CI 1.23-4.00) and body temperature ≥ 37.5°C (aOR: 2.34, 95% CI 1.35-4.04) whereas influenza viral carriage was associated with body temperature ≥ 37.5°C (aOR: 4.48, 95% CI 2.53-7.93). CONCLUSION: We observed a high nasopharyngeal viral carriage among children with WHO-defined fast-breathing pneumonia in Pakistan. Fever, difficulty in breathing, hypoxia and vaccination status are important clinical predictors for viral nonsevere community-acquired pneumonia.

Secondary attack rates and determinants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) household transmission in Pakistan: A case-ascertained prospective, longitudinal study.

BACKGROUND: Households are considered ideal settings for studying the transmission dynamics of an infectious disease. METHODS: A prospective study was conducted, based on the World Health Organization FFX protocol from October 2020 to January,2021. Household contacts of laboratory-confirmed index cases were followed up for their symptomatic history, nasal swabs for RT-PCR,and blood samples for anti-SARS CoV-2 antibodies were collected at enrollment and days 7, 14 and 28. We estimated secondary attack rate (SAR), effective household case cluster size and determinants of secondary infection among susceptible household contacts using multivariable logistic regression. RESULTS: We enrolled 77 index cases and their 543 contacts. Out of these, 252 contacts were susceptible at the time of enrollment. There were 77 household clusters, out of which, transmission took place in 20 (25.9%) giving rise to 34 cases. The acquired secondary attack rate (SAR) was 14.0% (95% CI 9.0-18.0). The effective household case cluster size was 0.46 (95%CI 0.33,0.56). Reported symptoms of nausea and vomiting (aOR, 7.9; 95% CI, 1.4-45.5) and fatigue (aOR, 9.3; 95% CI, 3.8-22.7) were associated with SARS-CoV-2 transmission. CONCLUSIONS: We observed a low SARS-CoV-2 secondary attack rate in the backdrop of high seroprevalence and asymptomatic transmission among households in Karachi, Pakistan.

Association of maternal nutritional status and small for gestational age neonates in peri-urban communities of Karachi, Pakistan: findings from the PRISMA study.

BACKGROUND: Early pregnancy nutritional status can be associated with adverse birth outcomes such as small-for-gestational age (SGA) and low birth weight (LBW). BMI (Body Mass Index) and MUAC (Mid-upper arm circumference) are easy to use assessments and are indicative of the pre-pregnancy nutritional status if obtained in the first trimester. This study primarily assesses the association of maternal nutritional status using BMI and MUAC with SGA in a community-based cohort of Pakistani women. It also aims to determine the predictive ability of MUAC and BMI in predicting SGA. Secondarily, we assessed the association between maternal nutrition and large for gestational age (LGA) and LBW. METHODS: This study is a secondary analysis of an ongoing pregnancy cohort "Pregnancy Risk Infant Surveillance and Measurement Alliance (PRISMA)"in Ibrahim Hyderi and Rehri Goth, Karachi. PRISMA participants who were enrolled between January 2021 to August 2022 were included given they had a gestational age < 14 weeks confirmed via ultrasound, MUAC and BMI measurements were available and birth weight was captured within 72 hours. Multivariable logistic regression was used to determine an association between maternal nutritional status and SGA. The PRISMA study was approved by the Aga Khan University Ethics Review Committee (2021-5920-15,518). RESULTS: Of 926 women included in the analysis, 26.6% (n = 247) had a low MUAC (< 23 cm) while 18.4% (n = 171) were underweight (BMI < 18.5 kg/m2). Nearly one third of low MUAC and underweight women delivered SGA infants (34.4 and 35.1% respectively). Underweight women and women with low MUAC had a statistically significant association with SGA (Underweight: OR 1.49, 95% CI 1.1,2.4; Low MUAC-OR 1.64, 95% CI 1.2,2.3) as well as LBW (Underweight: OR-1.63, 95% CI 1.1,2.4; Low MUAC-OR-1.63, 95% CI 1.2,2.3). ROC curves showed that MUAC and BMI had modest predictability for SGA (AUC < 0.7). CONCLUSION: Maternal nutritional status as indicated by BMI and MUAC are strongly associated with adverse pregnancy outcomes including SGA, LGA and LBW. Although MUAC and BMI are widely used to determine maternal nutritional status, they have poor predictive ability for newborn size. Further research is needed to identify other tools or a combination of tools to better predict adverse birth outcomes in resource-limited settings and plan interventions.

Clinical experience of next generation sequencing based expanded carrier screening in high-risk couples from a tertiary healthcare center in Pakistan.

INTRODUCTION: Carrier screening for genetic conditions has long been a part of preconception and prenatal care. While the use of expanded carrier screening (ECS) is widely common in HICs (high income countries), the clinical actionability of ECS in LMICs (low middle income countries) with high consanguineous unions is not well-understood. METHOD: Retrospective chart review of couples who presented to the Prenatal Genetics Clinic at Aga Khan University Hospital, between the period of June 2018 and November 2022. All the statistical analyses were performed using the statistical software STATA version 17.0. RESULTS: Of the 202 individuals tested, 166 (82%) were identified to be carriers of at least one gene associated with a monogenic condition. Out of the 302 genes tested, individuals were found to be carriers of conditions associated with 87 genes. Clinical actionability of ECS was established in a total of 45 (45%) high risk couples undergoing screening using ECS. CONCLUSION: We report the first clinical experience of using next generation sequencing based ECS in 101 high-risk couples seeking consultation in the Genetics Clinic, at a tertiary healthcare center in Pakistan, showing that over 80% high-risk individuals are carriers of at least one condition and 45% of couples receive an actionable result to making autonomous informed reproductive decisions in future pregnancies.

Investigating the unparalleled effects of economic growth and high-quality economic development on energy insecurity in China: A provincial perspective.

China has changed its focus from traditional high-speed economic growth to high-quality economic development (HQED) and the implementation of environmentally friendly practices. This transition can have parallel or unparallel impacts on energy insecurity (EIS). In this regards, HQED, inter Alia, is crucial in mitigating EIS and combating the energy crisis. Our study explores the impact of economic growth (EG) and HQED on EIS using the provincial panel data of China for the period 2011-2017. From the perspective of comparative analysis, the results reveal that HQED reduces EIS while EG increases it. The robustness checks indicate that industrial structure (IS) has a negative impact on EIS, whereas industrial structure upgrading (ISU) and green innovation (GI) have a positive influence. This implies that IS contributes to an increase in EIS, whereas ISU and GI result in a decrease in EIS. In addition, the analysis reveals that digital financial inclusion (DFI) exhibits a significant positive relation with EIS, albeit occasionally a negative but insignificant link. The policy implication is that the government should stimulate policies to promote HQED which reduces the EIS.

Triboelectric Energy Harvesting from Highly Conjugated Fused Aromatic Ladder Structure Under Extreme Environmental Conditions.

Practical application of triboelectric nanogenerators (TENGs) has been challenging, particularly, under harsh environmental conditions. This work proposes a novel 3D-fused aromatic ladder (FAL) structure as a tribo-positive material for TENGs, to address these challenges. The 3D-FAL offers a unique materials engineering platform for tailored properties, such as high specific surface area and porosity, good thermal and mechanical stability, and tunable electronic properties. The fabricated 3D-FAL-based TENG reaches a maximum peak power density of 451.2 µW cm-2 at 5 Hz frequency. More importantly, the 3D-FAL-based TENG maintains stable output performance under harsh operating environments, over wide temperature (-45-100 °C) and humidity ranges (8.3-96.7% RH), representing the development of novel FAL for sustainable energy generation under challenging environmental conditions. Furthermore, the 3D-FAL-based TENG proves to be a promising device for a speed monitoring system engaging reconstruction in virtual reality in a snowy environment.

Early to mid-pregnancy HbA1c levels and its association with adverse pregnancy outcomes in three low middle-income countries in Asia and Sub-Saharan Africa.

BACKGROUND: Hyperglycemia during pregnancy leads to adverse maternal and fetal outcomes. Thus, strict monitoring of blood glucose levels is warranted. This study aims to determine the association of early to mid-pregnancy HbA1c levels with the development of pregnancy complications in women from three countries in South Asia and Sub-Saharan Africa. METHODS: We performed a secondary analysis of the AMANHI (Alliance for Maternal and Newborn Health Improvement) cohort, which enrolled 10,001 pregnant women between May 2014 and June 2018 across Sylhet-Bangladesh, Karachi-Pakistan, and Pemba Island-Tanzania. HbA1c assays were performed at enrollment (8 to < 20 gestational weeks), and epidemiological data were collected during 2-3 monthly household visits. The women were followed-up till the postpartum period to determine the pregnancy outcomes. Multivariable logistic regression models assessed the association between elevated HbA1c levels and adverse events while controlling for potential confounders. RESULTS: A total of 9,510 pregnant women were included in the analysis. The mean HbA1c level at enrollment was found to be the highest in Bangladesh (5.31 ± 0.37), followed by Tanzania (5.22 ± 0.49) and then Pakistan (5.07 ± 0.58). We report 339 stillbirths and 9,039 live births. Among the live births were 892 preterm births, 892 deliveries via cesarean section, and 532 LGA babies. In the multivariate pooled analysis, maternal HbA1c levels of ≥ 6.5 were associated with increased risks of stillbirths (aRR = 6.3, 95% CI = 3.4,11.6); preterm births (aRR = 3.5, 95% CI = 1.8-6.7); and Large for Gestational Age (aRR = 5.5, 95% CI = 2.9-10.6). CONCLUSION: Maternal HbA1c level is an independent risk factor for predicting adverse pregnancy outcomes such as stillbirth, preterm birth, and LGA among women in South Asia and Sub-Saharan Africa. These groups may benefit from early interventional strategies.

Knowledge, attitudes, and practices toward seasonal influenza vaccination among healthcare workers and pregnant women in Pakistan: A mixed methods approach.

Vaccine hesitancy is a significant public health issue globally. We aim to document the barriers toward seasonal influenza vaccine uptake among healthcare workers (HCWs) and pregnant women (PW) in Pakistan. We performed a concurrent mixed methods study in four cities (Karachi, Islamabad, Quetta, and Peshawar) across Pakistan from September to December 2021. The quantitative component consisted of independent cross-sectional surveys for PW and HCWs, and the qualitative component comprised of in-depth interviews (IDIs) and focus group discussions (FGDs) among HCWs. Simple linear regression was used to determine the association of sociodemographic variables with knowledge, attitudes, and practices. Overall, 750 PW and 420 HCWs were enrolled. Among the PW, 44% were willing to receive the vaccine if available free of cost. Only 44% of the HCWs were vaccinated; however, 86% intended to get vaccinated and were willing to recommend the vaccine to their patients. HCWs refused vaccine due to side-effects (65%), cost (57%), and allergies (36%). An education level of secondary school and above was predictive of higher attitude and knowledge scores while having received the COVID-19 vaccine was associated with higher practice scores for both PW and HCWs. Several themes emerged from the interviews: 1) HCWs' knowledge of influenza and its prevention, 2) HCWs' perception of motivators and barriers to influenza vaccine uptake and 3) HCWs' attitudes towrd vaccine promotion. We report low influenza vaccine coverage among HCWs and PW in Pakistan. Educational campaigns addressing misconceptions, and improving affordability and accessibility through government interventions, can improve vaccine uptake.

Capital structure determinants across sectors: Comparison of observed evidences from the use of time series and panel data estimators.

This comparative study is an attempt to explore the determinants of capital structure for Malaysian firms listed in various sectors level. Within the framework of traditional and moderate dynamic capital structure theories, the key determinants such as fixed assets, current assets, return on equity, size, earning per share and total assets are tested in relation to the debt-equity ratio. The large-scale study entails data collected from 551 listed firms of Bursa Malaysia main market over 12 years period i.e. 2005-2016. Notably, this study combines Time Series econometrics with Panel Data analysis to enhance methodological robustness. Moreover, the comparative analysis approach is designated to recognize the most persistent capital structure determinants. In the first place, the Multiple Regression analysis (MRA) is selected as a baseline estimation method. Subsequently, the Auto Regression Distributed Lag model (ARDL), the Panel Data Static models, and Dynamic model via the Generalized Method of Moments (GMM) are employed to identify the capital structure determinants for the firms listed at Bursa Malaysia. The outcomes are surprising and indicate that the entire market is primarily controlled by the studied determinant total assets, which is significant in both construction and property sectors through MRA, ARDL, and GMM analysis. Technically, the significant role of tangibility and the existence of speed of adjustment across sectors imply that the Dynamic Capital Structure is the most prominent among all, followed by the Dynamic Trade-off theory.

Investigating the impact of prior COVID-19 on IgG antibody and interferon γ responses after BBIBP-CorV vaccination in a disease endemic population: A prospective observational study.

Background and Aims: COVID-19 vaccinations have reduced morbidity and mortality from the disease. Antibodies against severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) have been associated with immune protection. Seroprevalence studies revealed high immunoglobulin G (IgG) antibody levels to SARS-CoV-2 in the Pakistani population before vaccinations. We investigated the effect of BBIBP-CorV vaccination on circulating IgG antibodies and interferon (IFN)-γ from T cells measured in a cohort of healthy individuals, with respect to age, gender, and history of COVID-19. Methods: The study was conducted between April and October 2021. BBIBP-CorV vaccinated participants were followed up to 24 weeks. Antibodies to SARS-CoV-2 Spike protein and its receptor-binding domain (RBD) were measured. IFNγ secreted by whole blood stimulation of Spike protein and extended genome antigens was determined. Results: Study participants with a history of prior COVID-19 displayed a higher magnitude of IgG antibodies to Spike and RBD. IgG seropositivity was greater in those with prior COVID-19, aged 50 years or younger and in females. At 24 weeks after vaccination, 37.4% of participants showed IFN-γ responses to SARS-CoV-2 antigens. T cell IFN-γ release was higher in those with prior COVID-19 and those aged 50 years or less. Highest IFN-γ release was observed to extended genome antigens in individuals both with and without prior COVID-19. Conclusion: We found that IgG seropositivity to both Spike and RBD was affected by prior COVID-19, age and gender. Importantly, seropositive responses persisted up to 24 weeks after vaccination. Persistence of vaccine induced IgG antibodies may be linked to the high seroprevalence observed earlier in unvaccinated individuals. Increased T cell reactivity to Spike and extended genome antigens reflects cellular activation induced by BBIBP-CorV. COVID-19 vaccination may have longer lasting immune responses in populations with a higher seroprevalence. These data inform on vaccination booster policies for high-risk groups.

Frequency and Factors of Sleep Paralysis Among Medical Students of Karachi.

INTRODUCTION: Sleep paralysis is a prevalent phenomenon characterized by suffocation, immobility, and hallucinations. Its causes remain unknown, although the neurotransmitter imbalance is suggested as a potential factor. This condition is closely associated with hallucinations and a sense of intrusion, often observed in patients with narcolepsy, hypertension, and seizures. METHODS: A cross-sectional study was conducted in various medical colleges in Karachi, involving 297 participants aged 18 to 30 years. The participants were divided into groups based on gender and year of study. They were surveyed about the frequency of sleep paralysis episodes, their beliefs about the phenomenon, sleep routines, and academic impacts. RESULTS: Among the respondents, a significant number of females (n=209, 70.3%) reported experiencing sleep paralysis. The overall mean age was 20±2.0 years. Correlation analysis revealed an insignificant relationship between depression and mental anxiety (p=0.147). Similarly, no significant association was found when comparing the occurrence of sleep paralysis (p=0.16). However, a notable finding was the significant link between sleep paralysis and its impact on academics (p=0.043). CONCLUSION: This study highlighted the frequency of sleep paralysis among medical students, particularly among females. Furthermore, it emphasizes the diverse beliefs held by individuals regarding these frightening episodes. To address this neglected issue, it is essential to conduct awareness sessions aimed at understanding and alleviating sleep paralysis in individuals' lives.