SARS-CoV-2: Current trends in emerging variants, pathogenesis, immune responses, potential therapeutic, and vaccine development strategies

Synergistic Effect of Maternal Micronutrient Supplementation on ORFV DNA Vaccine Immune Response in a Pregnant Model

Contagious ecthyma is a contagious zoonotic disease caused by the Orf virus that can infect farm animals and humans, but no vaccine is available for pregnant mothers. Excessive oxidative stress during pregnancy can suppress the vaccine immune response in pregnant mothers; hence, maternal micronutrient supplementation could effectively improve the immune response, health, and oxidative status during pregnancy. In this study, we employed an 8-week-old pregnant rat model to receive a single intramuscular dose of 200 µg of ORF DNA vaccine with or without vitamin E and selenium supplementation to evaluate their effect on immune responses (specific IgG and IgG isotypes), oxidative stress, liver enzymes, and blood glucose levels in maternal-neonatal serum and milk secretions. Additionally, antioxidant-related gene expressions were analyzed in the maternal placenta and pups' liver. The results showed that supplementation of vitamin E and selenium with ORF DNA vaccination increased the production of specific antibody and IgG isotypes (IgG1 and IgG2a) and reduced the oxidative stress in neonatal-maternal serum and milk compared to both the control group and those vaccinated without supplementation (p < 0.05). Notably, the ORF DNA vaccine did not cause oxidative stress and hepatic damage. However, combined supplementation of vitamin E and selenium with DNA vaccination significantly decreased serum malondialdehyde (MDA) levels and improved the antioxidant-related enzyme activities of glutathione peroxidase (GPX), superoxide dismutase 1 (SOD1), and selenoprotein P (SELP) in the maternal placenta and liver of pups (p < 0.05). In conclusion, maternal supplementation of vitamin E and selenium enhanced the immune responses of the ORF DNA vaccine by mitigating oxidative stress in pregnant rats and could thus be a promising strategy for better health outcomes for both mothers and neonates.

Automated breast tumor ultrasound image segmentation with hybrid UNet and classification using fine-tuned CNN model

Introduction

Breast cancer stands as the second most deadly form of cancer among women worldwide. Early diagnosis and treatment can significantly mitigate mortality rates.

Purpose

The study aims to classify breast ultrasound images into benign and malignant tumors. This approach involves segmenting the breast's region of interest (ROI) employing an optimized UNet architecture and classifying the ROIs through an optimized shallow CNN model utilizing an ablation study.

Method

Several image processing techniques are utilized to improve image quality by removing text, artifacts, and speckle noise, and statistical analysis is done to check the enhanced image quality is satisfactory. With the processed dataset, the segmentation of breast tumor ROI is carried out, optimizing the UNet model through an ablation study where the architectural configuration and hyperparameters are altered. After obtaining the tumor ROIs from the fine-tuned UNet model (RKO-UNet), an optimized CNN model is employed to classify the tumor into benign and malignant classes. To enhance the CNN model's performance, an ablation study is conducted, coupled with the integration of an attention unit. The model's performance is further assessed by classifying breast cancer with mammogram images.

Result

The proposed classification model (RKONet-13) results in an accuracy of 98.41 %. The performance of the proposed model is further compared with five transfer learning models for both pre-segmented and post-segmented datasets. K-fold cross-validation is done to assess the proposed RKONet-13 model's performance stability. Furthermore, the performance of the proposed model is compared with previous literature, where the proposed model outperforms existing methods, demonstrating its effectiveness in breast cancer diagnosis. Lastly, the model demonstrates its robustness for breast cancer classification, delivering an exceptional performance of 96.21 % on a mammogram dataset.

Conclusion

The efficacy of this study relies on image pre-processing, segmentation with hybrid attention UNet, and classification with fine-tuned robust CNN model. This comprehensive approach aims to determine an effective technique for detecting breast cancer within ultrasound images.

Efficient Selective Adsorption of SARS-CoV-2 via the Recognition of Spike Proteins Using an Affinity Spongy Monolith

Since the outbreak of COVID-19, SARS-CoV-2, the infection has been spreading to date. The rate of false-negative result on a polymerase chain reaction (PCR) test considered the gold standard is roughly 20%. Therefore, its accuracy poses a question as well as needs improvement in the test. This study reports fabrication of a substrate of an anti-spike protein (AS)-immobilized porous material having selective adsorption toward a spike protein protruding from the surface of SARS-CoV-2. We have employed an organic polymer substrate called spongy monolith (SPM). The SPM has through-pores of about 10 μm and is adequate for flowing liquid containing virus particles. It also involves an epoxy group on the surface, enabling arbitrary proteins such as antibodies to immobilize. When antibodies of the spike protein toward receptor binding domain were immobilized, selective adsorption of the spike protein was observed. At the same time, when mixed analytes of spike proteins, lysozymes and amylases, were flowed into an AS-SPM, selective adsorption toward the spike proteins was observed. Then, SARS-CoV-2 was flowed into the BSA-SPM or AS-SPM, amounts of SARS-CoV-2 adsorption toward the AS-SPM were much larger compared to the ones toward the BSA-SPM. Furthermore, rotavirus was not adsorbed to the AS-SPM at all. These results show that the AS-SPM recognizes selectively the spike proteins of SARS-CoV-2 and may be possible applications for the purification and concentration of SARS-CoV-2.

Dermatological Manifestations in COVID-19: A Case Study of SARS-CoV-2 Infection in a Genetic Thrombophilic Patient with Mthfr Mutation

The present case study describes the dermatological manifestations of COVID-19 in a patient with genetic thrombophilia (MTHFR–C677T mutation) and the identification of a SARS-CoV-2 variant of interest (VOI). A female patient, 47 years old, unvaccinated, with thrombophilia, was diagnosed with COVID-19. She presented with urticarial and maculopapular eruptions from the seventh day of symptoms, which progressed to multiple lesions with dark centers (D-dimer value > 1450 ng/mL). The dermatological manifestations disappeared after 30 days, corroborating the reduction in D-dimer levels. Viral genome sequencing revealed infection by the VOI Zeta (P.2). Antibody testing, performed 30 days after the onset of symptoms, detected only IgG. The virus neutralization test showed the highest neutralizing titer for a P.2 strain, validating the genotypic identification. Lesions were suggested to be due to infection in skin cells causing a direct cytopathic effect or release of pro-inflammatory cytokines triggering erythematous and urticarial eruptions. In addition, vascular complications are also proposed to be due to the MTHFR mutation and increased D-dimer values. This case report is an alert about COVID-19 in patients with pre-existing vascular diseases, especially in unvaccinated patients, by VOI.

The protection quest is a primary key to sharing the neutralizing antibody response to cover against all emerging VOCs based on BIV1-CovIran studies

Over time, the antigenic evolution of emerging variants of SARS-CoV-2 has demanded the development of potential protective vaccines. Administration of additional doses of current vaccines based on the WT spike protein may boost immunity, but their effectiveness has dwindled for patients with more recent variants. Here, we studied the neutralization activity of post-WT strain-based vaccination and a structural simulation in-silico based on the interactions of the RBD-hACE2 as the key to initiating infection among the VOCs of SARS-CoV-2. Our data display shows that WT sera showed a markedly greater reduction in Delta and Omicron, suggesting that the Wuhan-based vaccines may be more susceptible to breakthrough and new VOCs. According to the MD simulation, mutations of Omicron result in a significant change in the variant charge distribution throughout the binding interface that consequently alters the critical interface electrostatic potential in comparison to other variants. This observation provides new insights into immunization policy and next-generation vaccine development.

Global emerging Omicron variant of SARS-CoV-2: Impacts, challenges and strategies

Newly emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are continuously posing high global public health concerns and panic resulting in waves of coronavirus disease 2019 (COVID-19) pandemic. Depending on the extent of genomic variations, mutations and adaptation, few of the variants gain the ability to spread quickly across many countries, acquire higher virulency and ability to cause severe disease, morbidity and mortality. These variants have been implicated in lessening the efficacy of the current COVID-19 vaccines and immunotherapies resulting in break-through viral infections in vaccinated individuals and recovered patients. Altogether, these could hinder the protective herd immunity to be achieved through the ongoing progressive COVID-19 vaccination. Currently, the only variant of interest of SARS-CoV-2 is Omicron that was first identified in South Africa. In this review, we present the overview on the emerging SARS-CoV-2 variants with a special focus on the Omicron variant, its lineages and hybrid variants. We discuss the hypotheses of the origin, genetic change and underlying molecular mechanism behind higher transmissibility and immune escape of Omicron variant. Major concerns related to Omicron including the efficacy of the current available immunotherapeutics and vaccines, transmissibility, disease severity, and mortality are discussed. In the last part, challenges and strategies to counter Omicron variant, its lineages and hybrid variants amid the ongoing COVID-19 pandemic are presented.

Association between serologically confirmed COVID-19 infection and cognitive functioning in community dwelling older adults

Introduction

COVID-19 infection can impact the central nervous system, and is often associated with cognitive decline. However, there are no studies linking serologically confirmed COVID-19 infection with objectively assessed cognitive functioning. We explored whether presence of SARS-CoV-2 antibodies account for variability in participants' scores on a neuropsychological assessment.

Methods

In this cross-sectional study participants were 657 (mean age = 72.97; SD = 6.07 years; women = 47.7%) individuals randomly selected from the general population of the canton of Zurich and included in the Corona Immunitas study. We conducted serological tests between October 2020 and May 2021 to detect and quantify SARS-CoV-2 antibodies in peripheral venous blood samples. We assessed cognitive function, vaccination status (vaccinated; not vaccinated), number of health conditions, and demographic variables between January and August 2021. We studied the association between seropositivity and global cognitive function and five cognitive domains (language expression, language comprehension, temporal orientation, spatial orientation, and memory) with linear regression models. Based on SARS-CoV-2 antibodies and vaccination status, we stratified participants into three groups: No SARS-CoV-2 antibodies (N = 402); SARS-CoV-2 antibodies due to vaccination (N = 218); history of SARS-CoV-2 infection and no vaccination (N = 37).

Results

In the regression model adjusted for age, sex, educational level, and number of health conditions, compared to those without SARS-CoV-2 antibodies, those with SARS-CoV-2 antibodies due to vaccination had better global cognitive functioning (Standardized beta = 0.10; 95% CI = 0.02; 0.17), and those with SARS-CoV-2 antibodies due to infection had poorer cognitive functioning (Standardized beta = -0.10; 95% CI = -0.18; -0.03). Regarding cognitive domains, compared to those without SARS-CoV-2 antibodies, those with SARS-CoV-2 antibodies due to infection scored more poorly on language comprehension and temporal orientation, and those with SARS-CoV-2 antibodies due to vaccination scored better on memory.

Discussion

By linking serologically confirmed presence of SARS-CoV-2 antibodies to poorer global cognitive functioning in community dwelling older adults we strengthen existing evidence in support of cognitive decline related to COVID-19. Given the large number of infected older adults, and the endurance of the pandemic, our results highlight the need to address COVID-19 related cognitive decline in the clinical and public health areas of prevention, diagnosis, and treatment.

Strategies to tackle SARS-CoV-2 Mu, a newly classified variant of interest likely to resist currently available COVID-19 vaccines

Several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have recently been reported in many countries. These have exacerbated the coronavirus disease 2019 (COVID-19)-induced global health threats and hindered COVID-19 vaccine development and therapeutic progress. This commentary discusses the potential risk of the newly classified Mu variant of interest, seeming a highly vaccine-resistant variant, and the approaches that can be adopted to tackle this variant based on the available evidence. The SARS-CoV-2 B.1.621 (Mu variant) lineage has shown approximately ten times higher resistance to neutralizing sera obtained from COVID-19 survivors or BNT161b2-vaccinated people than the parenteral B.1 lineage. Several urgent and long-term strategic plans, including quick genomic surveillance for uncovering the genetic characteristics of the variants, equitable global mass vaccination, booster dose administration if required, and strict implementation of public health measures or non-pharmaceutical interventions, must be undertaken concertedly to restrict further infections, mutations, or recombination of the SARS-CoV-2 virus and its deadly strains.

The Impact of Immune-Modifying Treatments for Skin Diseases on the Immune Response to COVID-19 Vaccines: a Narrative Review

Purpose of Review

SARS-CoV-2 has had a devastating global effect, with vaccinations being paramount in the public health strategy against COVID-19. Vaccinations have uncoupled infection from adverse COVID-19 outcomes worldwide. While immune-modifying therapies are effective for the management of skin diseases such as psoriasis and atopic dermatitis, these medications also impair protective immune responses. There has been longstanding uncertainty and concern over the impact of immune-modifying therapies on the effectiveness of vaccines; for example, it is well recognised that methotrexate impairs humoral responses to both influenza and pneumococcal vaccines. This narrative review aims to discuss the evidence to date on the impact of immune-modifying therapies on the immune response to COVID-19 vaccines, with a focus on the first two vaccine doses.

Recent Findings

Individuals receiving immune-modifying therapy are more likely to have attenuated humoral responses to a single dose of COVID-19 vaccine compared to healthy controls; however, this may be improved by a complete course of vaccination. B cell targeted biologics such as rituximab markedly impair the humoral response to both the first and second COVID-19 vaccination. There remains a paucity of data on cellular immune responses, with the few available studies indicating lower responses to two vaccine doses in individuals receiving immune-modifying therapies compared to healthy controls, which may impact the durability of immune responses.

Summary

Inadequate humoral immune responses to a single dose of vaccine in the context of immune-modifying therapy are improved by a complete course of vaccination. Individuals receiving immune-modifying treatments should be encouraged to take up a complete vaccine course to mitigate their risk against COVID-19. Research in large patient populations on the longevity/kinetics of the complex humoral and cellular response to subsequent vaccine doses, including against newer variants of concern, is warranted, in addition to data on immune correlates of vaccine clinical effectiveness.

A Bivalent COVID-19 Vaccine Based on Alpha and Beta Variants Elicits Potent and Broad Immune Responses in Mice against SARS-CoV-2 Variants

With the emergence and rapid spread of new pandemic variants, especially variants of concern (VOCs), the development of next-generation vaccines with broad-spectrum neutralizing activities is of great importance. In this study, SCTV01C, a clinical stage bivalent vaccine based on trimeric spike extracellular domain (S-ECD) of SARS-CoV-2 variants Alpha (B.1.1.7) and Beta (B.1.351) with a squalene-based oil-in-water adjuvant was evaluated in comparison to its two corresponding (Alpha and Beta) monovalent vaccines in mouse immunogenicity studies. The two monovalent vaccines induced potent neutralizing antibody responses against the antigen-matched variants, but drastic reductions in neutralizing antibody titers against antigen-mismatched variants were observed. In comparison, the bivalent vaccine SCTV01C induced relatively higher and broad-spectrum cross-neutralizing activities against various SARS-CoV-2 variants, including the D614G variant, VOCs (B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.1.529), variants of interest (VOIs) (C.37, B.1.621), variants under monitoring (VUMs) (B.1.526, B.1.617.1, B.1.429, C.36.3) and other variants (B.1.618, 20I/484Q). All three vaccines elicited potent Th1-biased T-cell immune responses. These results provide direct evidence that variant-based multivalent vaccines could play important roles in addressing the critical issue of reduced protective efficacy against the existing and emerging SARS-CoV-2 variants.