Search Results (62)

Plant-derived products, particularly essential oils, represent a promising source of antiviral scaffolds. Although Populus balsamifera L. has been traditionally used to manage respiratory ailments and infections, the antiviral potential of its bud essential oil remains unexplored. In this study, we evaluated the in vitro antiviral cytoprotective activity of P. balsamifera bud essential oil and its major constituents against HCoV-OC43, a human betacoronavirus associated with seasonal respiratory infections, using a cell-based cytoprotection assay. The assay reliably detected the activity of reference antivirals, including chloroquine (EC₅₀ = 0.11 ± 0.01 µg/mL), molnupiravir, and fluvoxamine, supporting its suitability for antiviral screening. Under these conditions, P. balsamifera bud essential oil exhibited strong cytoprotective activity, with an EC₅₀ of 3.3 ± 0.5 µg/mL. Chemical analysis revealed a sesquiterpene-rich composition. Two major constituents, α-bisabolol and nerolidol, also showed marked cytoprotection, with EC₅₀ values of 2.7 ± 0.3 µg/mL and 2.6 ± 0.4 µg/mL, respectively, supporting their contribution to the overall activity of the oil. To our knowledge, this study provides the first experimental evidence of antiviral cytoprotective activity of P. balsamifera bud essential oil against a human coronavirus and identifies α-bisabolol and nerolidol as active compounds in this model. Full article

The coronavirus disease 19 pandemic disrupted pediatric respiratory infections through non-pharmaceutical interventions and altered contact patterns. Long-term comparisons across the pandemic timeline in children remain limited. In this study, we analyzed 15,657 respiratory specimens from patients ≤ 18 years at Dankook University Hospital (2007–2023) using multiplex polymerase chain reaction assays targeting 15 viruses. Age-stratified positivity rates were compared across pandemic phases. Children ≤ 6 years comprised 88.61% of the study population. Human rhinovirus showed the highest detection rate (24.06%), followed by adenovirus (12.33%), respiratory syncytial virus-subtypes A and B (RSV-A: 11.13%; RSV-B: 8.65%), human parainfluenza virus-type 3 (HPIV-3; 6.21%), human metapneumovirus (HMPV; 5.33%), and enterovirus (2018–2023; EV; 10.96%). Monthly distributions differed (p < 0.001). RSV peaked in late autumn and winter; influenza and seasonal coronaviruses in winter and spring; HMPV, HPIV-3, EV, and human bocavirus in summer and fall. Positivity declined during the pandemic, rebounding in 2023, most prominently among children aged 1–6 years (84.91%). HPIV-3 and EV increased (p < 0.001). RSV-A predominated pre-pandemic, whereas RSV-B showed a non-significant relative increase post-pandemic; no subtype differences occurred during the pandemic. Findings demonstrate pathogen-specific shifts in predominance and seasonality and support ongoing surveillance and pediatric care planning. Full article

Human coronavirus 229E (HCoV-229E) is an alphacoronavirus that typically causes mild upper respiratory infections but remains understudied in terms of its long-term immuno-ecological behavior. Although the COVID-19 pandemic markedly altered human behavior and viral transmission, extended circulation patterns of HCoV-229E remain poorly defined. We analyzed annual, seasonal, and age-specific trends using real-time PCR–based respiratory virus surveillance data from Dankook University Hospital collected between 2007 and 2024. Among 23,284 nasopharyngeal swab specimens, 344 were positive for HCoV-229E (overall positivity, 1.43%). Positivity declined significantly over time (OR per year, 0.916; 95% CI, 0.894–0.939; p < 0.001). Compared with spring (1.04%), positivity was highest in winter (2.69%) and lowest in summer (0.29%) (both p < 0.001), whereas autumn (0.81%) showed no significant difference. Early childhood (1–5 years) demonstrated a higher likelihood of positivity than infants aged 0 years (aOR, 1.51; p = 0.007) and the highest crude positivity rate (1.89%). Although underlying mechanisms were not directly assessed, this long-term analysis documents a persistent decline and attenuation of seasonal dominance in HCoV-229E detection beyond the period of pandemic-related suppression. These findings underscore the value of sustained laboratory-based surveillance in identifying and tracking long-term changes in respiratory virus circulation patterns and in supporting public health monitoring aligned with Sustainable Development Goal 3 (SDG 3). Full article

Several researchers have documented the occurrence of the unfamiliar severe acute respiratory syndrome coronavirus 2 ribonucleic acid (also known as SARS-CoV-2 RNA) in various raw wastewater (WW) samples analyzed globally. The efficiency of strategic WW-based epidemiology (WBE) approach as a timely cautioning tool for human coronavirus disease-2019 (COVID) and other similar outbreaks is highly promising. This strategy offers a cost-effective, population-wide surveillance tool that can detect rising case trends, from days to weeks before clinical reports, thus enabling proactive public health interventions. This study aimed to detect the occurrence of the viral genome in WW over four seasons, which contributes to the database for multi-plant surveillance research in South Africa. About 480 WW influent samples were amassed from ten sampling points situated in nine wastewater treatment facilities (WWTFs) in Amathole District Municipality (ADM) located in the Province of Eastern Cape (EC), South Africa (SA). The study was carried out for a period of one year. Quantitative real-time polymerase chain reaction (i.e., RT-PCR) was operated to identify the viral genomes in the respective total RNA samples. Of the 480 extracted RNA samples, 210 (44%) were positive with viral genome copies (gc) that ranged from 700 to 40,000 GC/mL. Our results were contrasted with existing COVID-19-positive cases throughout the COVID omicron wave in the ECP. Variations in gc were observed across different seasons, with the highest GC observed in winter. In contrast, there were significant inconsistencies in the existing data of COVID-19 clinical cases, thus indicating no connection between both data. However, with more similar studies, advanced innovative WBE strategies could possibly act as prompt warning tools to signal public health officials about potential future outbreaks. Full article

Seasonal human coronaviruses (HCoVs), including HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1, circulate globally in an epidemic pattern and account for a substantial proportion of common cold cases, particularly in infants, the elderly, and immunocompromised individuals. Although clinical manifestations are typically mild, these HCoVs exhibit ongoing antigenic drift and have demonstrated the potential to cause severe diseases in certain populations, underscoring the importance of developing targeted and broad-spectrum vaccines. This review systematically examines the pathogenesis, epidemiology, genomic architecture, and major antigenic determinants of seasonal HCoVs, highlighting key differences in receptor usage and the roles of structural proteins in modulating viral tropism and host immunity. We summarize recent advances across various vaccine platforms, including inactivated, DNA, mRNA, subunit, viral-vectored, and virus-like particle (VLP) approaches, in the development of seasonal HCoV vaccines. We specifically summarize preclinical and clinical findings demonstrating variable cross-reactivity between SARS-CoV-2 and seasonal HCoV vaccines. Evidence indicates that cross-reactive humoral and cellular immune responses following SARS-CoV-2 infection or vaccination predominantly target conserved epitopes of structural proteins, supporting strategies that incorporate conserved regions to achieve broad-spectrum protection. Finally, we discuss current challenges in pathogenesis research and vaccine development for seasonal HCoVs. We propose future directions for the development of innovative pan-coronavirus vaccines that integrate both humoral and cellular antigens, aiming to protect vulnerable populations and mitigate future zoonotic spillover threats. Full article

Human adenoviruses (HAdVs; genus Mastadenovirus, family Adenoviridae) are major etiologic agents of respiratory infections, exerting a disproportionately large impact on children. However, no long-term study to date has spanned pre- and post-pandemic periods in a Korean tertiary setting. Here, we retrospectively analyzed 23,284 nasopharyngeal swabs collected between 2007 and 2024 at a tertiary medical center in South Korea. Most specimens were obtained from inpatients and outpatients presenting with fever or respiratory symptoms for differential viral diagnosis. HAdV was detected using real-time PCR, and positivity rates were compared by year, season, and age group. Overall, 2043 tested positive for HAdV. Annual positivity peaked in 2010, 2013, and 2016, followed by a sharp decline during the coronavirus disease 2019 pandemic, reaching its lowest level in 2024. Positivity was higher in summer and spring than in winter. Children aged 1–5 years had the highest positivity, whereas adults and older adults showed markedly lower rates. The disproportionate burden among children underscores the need for targeted surveillance, school-based infection control, and region-specific preparedness strategies. These findings provide crucial long-term evidence into adenovirus circulation in the post-pandemic era and provides an evidence-based foundation for future public health policy and infection control planning. Full article

Artificial intelligence (AI) techniques—ranging from hybrid mechanistic–machine learning (ML) ensembles to gradient-boosted decision trees, support-vector machines, and deep neural networks—are transforming the management of seasonal influenza, respiratory syncytial virus (RSV), human immunodeficiency virus (HIV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptom-based triage models using eXtreme Gradient Boosting (XGBoost) and Random Forests, as well as imaging classifiers built on convolutional neural networks (CNNs), have improved diagnostic accuracy across respiratory infections. Transformer-based architectures and social media surveillance pipelines have enabled real-time monitoring of COVID-19. In HIV research, support-vector machines (SVMs), logistic regression, and deep neural network (DNN) frameworks advance viral-protein classification and drug-resistance mapping, accelerating antiviral and vaccine discovery. Despite these successes, persistent challenges remain—data heterogeneity, limited model interpretability, hallucinations in large language models (LLMs), and infrastructure gaps in low-resource settings. We recommend standardized open-access data pipelines and integration of explainable-AI methodologies to ensure safe, equitable deployment of AI-driven interventions in future viral-outbreak responses. Full article

Viral lung infections are a never-ending threat to public health due to the emergence of new variants and their seasonal nature. While vaccines offer some protection, the need for effective antiviral drugs remains high. The existing research methods using 2D cell culture and animal models have their limitations. Human cell-based tissue engineering approaches hold great promise for bridging this gap. Here, we describe a microextrusion bioprinting approach to generate three-dimensional (3D) lung models composed of four cell types: endothelial cells, primary fibroblasts, macrophage cells, and epithelial cells. A549 and Calu-3 cells were selected as epithelial cells to simulate the cells of the lower and upper respiratory tract, respectively. Cells were bioprinted in a hydrogel consisting of alginate, gelatin, hyaluronic acid, collagen, and laminin-521. The models were cultured under air–liquid interface (ALI) conditions to further enhance their physiological relevance as lung cells. Their viability, metabolic activity, and expression of specific cell markers were analyzed during long-term culture for 21 days. The constructs were successfully infected with both a seasonal influenza A virus (IAV) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant, demonstrating their potential for studying diverse viral infections. Full article

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the zoonotic virus responsible for the COVID-19 pandemic, has caused global health and economic disruption. American mink (Neovison vison) are highly susceptible to SARS-CoV-2 and capable of transmitting it to both mink and humans. We previously reported the first detection of SARS-CoV-2 in feral mink, with two positive cases among 13 animals in the upper courses of two rivers in the Valencian Community, eastern Spain. Here, we expand that study with 60 additional feral mink sampled from November 2020 to May 2022. Four new positives were identified by two-step RT-PCR assay on necropsy samples, including nasal and rectal swabs, lung tissue, lymph nodes, and fetuses from three pregnant females. In total, six of 73 mink tested positive, all with low viral loads. Sanger sequencing confirmed infection and revealed clustering with the B.1.177 and Alpha variants. Body weight and reproductive status analyses indicated seasonal breeding and high population turnover, consistent with other wild mink populations. Our findings reveal that SARS-CoV-2 circulation is limited in feral mink, at least in this region. They underscore the key importance of wildlife surveillance as an element of the One Health strategy, which encompasses humans, animals, and the environment. Full article

The global outbreak of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) and the strategies adopted by different nations have affected and altered the transmission of different respiratory pathogens around the world. We examined the impact of SARS-CoV-2 on the spread of respiratory viruses in the period between 2021 and 2024 in patients with severe influenza-like symptoms in the Lazio region using multiplex PCR tests for the identification of common seasonal respiratory viruses. Our data reveal a change in the transmission of respiratory viruses from 2021 to 2024, with a sharp decline in the transmission of SARS-CoV-2 and a rise in the transmission of other respiratory viruses, especially influenza viruses, and human rhinovirus/enterovirus in 2024. Moreover, viral co-infections, both those involving two viruses and those involving three viruses, have also increased. This work shows how the spread of SARS-CoV-2 influenced the spread of other respiratory viruses over four years in patients with severe influenza-like symptoms in the Lazio region. In conclusion, the resurgence and fluctuation of various respiratory viruses emphasize the dynamic nature of viral epidemiology in the post-pandemic context and highlight the ongoing need for vigilant public health monitoring and intervention strategies. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel human coronavirus, emerged in late 2019 and rapidly evolved into a pandemic around the world. The coronavirus disease (COVID-19) pandemic has dramatically changed the epidemiology and seasonality of other traditional respiratory viruses, e.g., influenza, respiratory syncytial virus, enterovirus, etc. These traditional respiratory viruses have transmission mode and clinical symptoms similar to SARS-CoV-2 but may differ in clinical outcomes and management. Co-infection between SARS-CoV-2 and one or more traditional respiratory viruses have been reported in the literature but have shown mixed evidence in clinical outcomes. With SARS-CoV-2 evolving into mild Omicron variants, it is believed that SARS-CoV-2 co-circulates with other respiratory viruses, which in turn affect the epidemiology and clinical course of respiratory viral infections. In response to these changes, multiplex molecular tests for SARS-CoV-2 and one or more traditional respiratory viruses are attracting more attention in the field and have been developed into a variety of testing modalities. In this review, we describe the seasonality (i.e., in the Northern Hemisphere), epidemiology, and clinical significance of traditional respiratory viruses and their co-infection with SARS-CoV-2 in the post-COVID era. Furthermore, we review commonly used multiplex molecular tests and their applications for the detection of respiratory viruses and their co-infections. Altogether, this review not only sheds light on the epidemiology and clinical significance of respiratory viral infections and co-infections in the post-COVID era, and but also provides insights into the laboratory-based diagnoses of respiratory viral infections using multiplex molecular testing. Full article

Background/Objectives: mRNA vaccines have demonstrated strong immunogenicity and efficacy against SARS-CoV-2. However, the extent of antibody cross-reactivity against human seasonal coronaviruses, such as NL63, remains unclear. Furthermore, it is unknown whether pre-existing antibody responses against NL63 might influence the outcome of SARS-CoV-2 mRNA vaccination. Methods: We used a flow cytometry-based serological assay and an in vitro neutralization assay to analyze NL63 antibody responses in sera from SARS-CoV-2 mRNA-vaccinated mice and plasma samples from a vaccinated human cohort. Results: We found that the Moderna mRNA-1273 vaccine can generate cross-reactive antibodies against NL63. Importantly, SARS-CoV-2 mRNA vaccination did not boost pre-existing anti-NL63 responses in humans, and pre-existing NL63 antibody levels did not affect the antibody response induced by SARS-CoV-2 mRNA vaccination. Conclusions: These findings suggest that while SARS-CoV-2 mRNA vaccination can induce cross-reactive antibodies against NL63, pre-existing immunity to this seasonal coronavirus does not appear to significantly impact vaccine immunogenicity. These findings contribute to our understanding of the complex interplay between pre-existing immunity to seasonal coronaviruses and the immune response generated by SARS-CoV-2 mRNA vaccines. Full article

Background/Objectives: The impact of the coronavirus disease 2019 (COVID-19) pandemic on health was significant worldwide. The measures adopted to limit the spread of the virus had an indirect effect on the epidemiology of other infectious diseases with similar mechanisms of inter-human transmission. The present literature review analyzed the scenario of pediatric acute respiratory infections in the post-lockdown period compared to the pre-pandemic and lockdown periods. The different patterns of viruses’ outbreaks were evaluated according to the type of local COVID-19 restrictive measures and to the type of pathogen. Methods: Relevant scientific literature published between March 2020 and November 2024 was identified by means of electronic keyword searches in the PubMed, Scopus, and Cochrane Library databases. Results: Worldwide implementation of non-pharmacological public health interventions aimed at limiting the COVID-19 pandemic resulted in a measurable effect on the circulation of other common respiratory viruses, significantly affecting their usual seasonality. Most viruses significantly reduced their activity during the lockdown period but returned to or exceeded historical levels after discontinuation of preventive non-pharmacological measures. For many respiratory viruses, particularly respiratory syncytial virus, an off-season increase was reported. Conclusions: The non-pharmacological interventions, which effectively helped limit the COVID-19 pandemic, resulted in relevant epidemiologic changes in most common respiratory viruses. Given the different seasonality and clinical severity observed for some pathogens after lockdown, possible future off-season or more severe epidemics should be expected. Full article

The coronavirus disease 2019 (COVID-19) pandemic profoundly disrupted the epidemiology of respiratory viruses, driven primarily by widespread non-pharmaceutical interventions (NPIs) such as social distancing and masking. This eight-year retrospective study examines the seasonal patterns and incidence of influenza virus, respiratory syncytial virus (RSV), and other respiratory viruses across pre-pandemic, pandemic, and post-pandemic phases in Jalisco, Mexico. Weekly case counts were analyzed using an interrupted time series (ITS) model, segmenting the timeline into these three distinct phases. Significant reductions in respiratory virus circulation were observed during the pandemic, followed by atypical resurgences as NPIs were relaxed. Influenza displayed alternating subtype dominance, with influenza A H3 prevailing in 2022, influenza B surging in 2023, and influenza A H1N1 increasing thereafter, reflecting potential immunity gaps. RSV activity was marked by earlier onset and higher intensity post-pandemic. Other viruses, including human rhinovirus/enterovirus (HRV/HEV) and parainfluenza virus (HPIV), showed altered dynamics, with some failing to return to pre-pandemic seasonality. These findings underscore the need for adaptive surveillance systems and vaccination strategies to address evolving viral patterns. Future research should investigate the long-term public health implications, focusing on vaccination, clinical outcomes, and healthcare preparedness. Full article

Coronavirus disease 2019 (COVID-19) can be tracked through wastewater, enabling the prediction of cases by wastewater-based epidemiology (WBE). An issue that complicates WBE is that humans are not static, moving in and out of sewer drainage areas throughout the day. During large-scale events (i.e., sports, music, culture), large populations move during a small time frame in certain areas, with some individuals carrying along the virus. To track such human movement anonymously, cell phone location data (using StreetLight^®) were used to monitor the flow of populations in and out of the sewershed during football games at the University of Oklahoma for two consecutive seasons (2020–2021). Hourly wastewater samples were taken during gamedays (Saturday to Sunday mornings) and on one control Saturday (no game) for each season, along with controls in the form of composite samples for days surrounding the events. Hourly population data during gamedays allowed for the calculation of viral load per capita, which increased for most games, indicating the existence of incoming infected individuals in the region. This case study aims to help decision makers understand how hosting large-scale events during this and potential future disease outbreaks may impact public health. Full article