Search Results (5,755)

Photodynamic inactivation (PDI) is a relatively new approach for targeting viruses. Recently, PDI has been shown to be effective against various viral infections, with a low probability of resistance development. The study presents PDI towards the infectivity of human coronavirus (HCoV-OC43) at different stages of its propagation and through different mechanisms of action. Two tetra-methylpyridiloxy-substituted gallium and zinc phthalocyanines (GaPcMe and ZnPcMe), exposed to light from a 660 nm light-emitting diode (LED), were evaluated and showed a high potential against HcoV-OC43. The effect of PDI on extracellular virions and the stage of their adsorption was assessed using the finite dilution method and by determining changes in viral infectivity (Δlgs). The impact on the viral replicative cycle was assessed by inhibition of the cytopathic effect (CPE). The direct effect on virions was notable for both phthalocyanines, but was significantly more pronounced for ZnPcMe (Δlg = 4). A strong inhibitory effect on virus adsorption was observed for ZnPcMe (from Δlg = 3.5 to complete inhibition, Δlg = 5.0, depending on the irradiation time). Both GaPcMe and ZnPcMe demonstrate PDI at an early stage of the virus replication cycle. This is reflected in the high photoinactivation indices PII = 44.0 for ZnPcMe and PII = 23.3 for GaPcMe. The binding potential of GaPcMe and ZnPcMe toward viral and host protein targets was investigated using molecular docking and molecular dynamics (MD) simulations. The computational panel included HCoV-OC43 3CLpro (Nsp5, PDB 9PAM) and homologous SARS-CoV-2 proteins, namely Nsp5, Nsp12, M protein, S protein, as well as human ACE2. The docking results indicated that both phthalocyanines exhibit notable theoretical binding affinity toward these targets. Full article

Caused by the SARS-CoV-2 virus, the COVID-19 pandemic is still considered a complex challenge, with manifestations not only of respiratory issues, but also conditions related to chronic cerebrovascular damage. Endothelial biomarkers, neuropathological and neuroimaging findings indicate endothelial dysfunction, microthrombosis, and disruption of the blood–brain barrier (BBB) are central mechanisms for acute and chronic ischemic and hemorrhagic cerebral events. Understanding these mechanisms is vital to reducing their impact on population health, whether through treatment or prevention of adverse outcomes. The objective of this study is to perform a review of the scientific literature on the post-infection effects of SARS-CoV-2 affecting the cerebral endothelium and the BBB, correlating them with potential clinical outcomes. Material and Methods: Analysis of studies extracted from the PubMed database using the following terms: Long-COVID “AND” SARS-CoV-2 “AND” blood–brain barrier. Inclusion criteria: keywords, publications related to the topic, and primary studies published after peer review. Exclusion criteria: preprint studies, publication outside of the timeframe 2020–2025, study design not compatible with this research, and full text not available. Results: An initial 121 studies were identified, of which 105 were excluded due to not meeting all inclusion criteria and 6 studies were inaccessible due to not being in the English language and full-text access limitations. Fifteen articles were included in the analysis, for topics as expression of viral receptors in the endothelium, markers of their activation, cerebral microvascular injury and coagulopathies. To clarify the pathogenic cascade, the evidence was stratified by biological model where in vitro evidence demonstrates that the Spike protein induces direct endothelial toxicity and platelet aggregation, establishing the primary molecular insult. Animal models confirm the translation of this insult into structural degradation of the BBB and pericyte loss. Clinically, infection-phase findings, characterized by multifocal microthrombosis and permeability spikes, act as the determining event that predisposes to the persistent neuroinflammatory environment. Biomarkers of BBB disruption and neuronal damage were consistently reported, with persistence of BBB dysfunction modifying risk stratification and rehabilitation efforts. Reported cases of Long-COVID demonstrated normalization of BBB markers without correlation with long-term symptoms, suggesting that other mechanisms are involved in Long-COVID. Conclusion: Cerebral endotheliopathies and BBB dysfunction in patients with COVID-19 continue to impact the health of the population. The scientific literature indicates that SARS-CoV-2 induces cerebral endothelial injury, BBB disruption, and an increased risk of vascular events related to endotheliopathy, inflammation, and hypercoagulability. Understanding the impact of COVID-19 pathology on the population and developing prospective studies is essential to quantify the prevalence and mechanisms of brain injury. The identification of molecular targets and infection pathways are promising toward defining both preventive and therapeutic strategies to improve outcomes in the Long-COVID population. Full article

Background/Objectives: SARS-CoV-2, influenza viruses, and respiratory syncytial virus (RSV) remain major causes of adult hospitalizations, but contemporary comparative data are limited. This study compared the epidemiological characteristics, clinical presentation, and outcomes of adults hospitalized with these infections during the 2025/2026 epidemic season in Poland. Methods: We conducted a retrospective multicenter study of consecutive adults hospitalized with laboratory-confirmed COVID-19, influenza, or RSV infection between September 2025 and April 2026. Demographic characteristics, comorbidities, vaccination status, clinical features, laboratory findings, and outcomes were analyzed. Independent predictors of in-hospital mortality were identified using multivariable logistic regression. Results: The study included 604 patients: 255 with COVID-19, 314 with influenza, and 35 with RSV infection. Distinct seasonal patterns were observed, with COVID-19 peaking in autumn, influenza in winter, and RSV in early spring. Most hospitalized patients were elderly and unvaccinated. RSV patients were older, more frequently affected by multimorbidity, ischemic heart disease, and cancer, and showed the greatest respiratory impairment, including the highest rates of hypoxemia and pneumonia. Influenza was characterized by more frequent fever, headache, and myalgia. Despite lower pneumonia rates, COVID-19 was associated with the highest in-hospital mortality (13.7%) and remained an independent predictor of death (aOR = 3.23, 95%CI: 1.68–6.22). Antibiotic use was common across all cohorts (62–77%). Conclusions: COVID-19 remained associated with the highest mortality among hospitalized adults, whereas RSV contributed substantially to respiratory morbidity in older individuals. These findings support improved vaccination uptake, continued surveillance, hospital preparedness, and antimicrobial stewardship. Full article

Chalcones are naturally occurring open-chain flavonoids widely distributed in plants and recognized for their broad spectrum of pharmacological activities. Their versatile scaffold allows for extensive structural modifications, leading to a diverse range of natural and synthetic derivatives with notable biological potential. In the context of viral infections, chalcones have demonstrated remarkable efficacy against a variety of human pathogens, including dengue virus, HIV, HCV, influenza A, SARS-CoV-2, and other emerging viruses. Beyond human health, several chalcones have shown potent activity against plant viruses such as tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV), and animal viruses including porcine reproductive and respiratory syndrome virus (PRRSV) and mammalian reovirus (MRV), underscoring their broad antiviral spectrum. These compounds act through multiple mechanisms, including the inhibition of viral enzymes (e.g., proteases, polymerases, and integrases), interference with viral entry and replication, and the modulation of host-related pathways. Recent advances in molecular docking, structure–activity relationship (SAR) studies, and synthetic optimization have further highlighted chalcones as a promising scaffold for antiviral drug discovery. Accordingly, this review summarizes and categorizes antiviral chalcones reported over the last two decades, emphasizing and critically discussing their molecular targets, mechanisms of action, and pharmacological potential as lead compounds. It also provides a comparative perspective on their pharmacological relevance by correlating their activities against standard therapeutic agents and reference inhibitors. Furthermore, the most recurrent viral targets were critically discussed regarding their conservation, expected genetic barriers to resistance, and the global SAR trends identified for the corresponding antiviral chalcones. Finally, in silico ADMET profiling of the most promising naturally occurring chalcones was performed to evaluate their drug-likeness and pharmacokinetic properties, offering guidance for future structural optimization and translational development. Collectively, these findings highlight the chalcone scaffold as a versatile platform for the development of novel antiviral agents targeting diverse viral and host pathways. Full article

Acute bronchiolitis is the leading cause of infant hospitalization worldwide, with respiratory syncytial virus (RSV) historically predominating. Prospective virological data for the 2025–2026 epidemic season in Morocco were lacking. A prospective observational cohort study was conducted at the Department of Pediatric Infectious Diseases and Clinical Immunology, Casablanca Mother-Child Hospital, from August 2025 through March 2026. Consecutive infants aged 1–24 months hospitalized with acute viral bronchiolitis underwent nasopharyngeal sampling and multiplex rapid antigen testing for RSV, influenza A, influenza B, and SARS-CoV-2. A total of 131 infants were enrolled (median age 4.8 months; male-to-female ratio 0.84:1). At least one virus was identified in 63 patients (48.1%; 95% CI 39.1–57.3%). RSV predominated: 49 sole infections and 2 co-infections with influenza A, totaling 51 positives (80.9% of virus-positive cases; 38.9% of the cohort). Influenza A totaled 8 cases (12.7%), including the 2 co-infections; influenza B accounted for 2 further cases (3.2%). SARS-CoV-2 was not detected. Epidemic activity peaked in January 2026 (65 admissions), declining through February (34) and March (12). All detected pathogens have licensed preventive options, supporting the introduction of nirsevimab, maternal RSV vaccination, and seasonal influenza vaccination as public health priorities in Morocco. Full article

Background/Objectives: Glycosylation can affect vaccine antigen structure and function, making site-specific glycan characterization relevant to antigen quality and comparability. However, quantitative approaches for comparing glycan microheterogeneity remain limited. This study evaluated the utility of the glycopeptide abundance distribution spectra framework for measuring similarity among site-specific glycosylation profiles in vaccines and antigen reference reagents across manufacturing conditions. Methods: Intact N-linked glycopeptides were characterized by nanoflow liquid chromatography–tandem mass spectrometry with stepped-energy fragmentation. Products included monovalent and quadrivalent influenza antigens produced in embryonated eggs, Madin–Darby canine kidney cells, or Spodoptera frugiperda cells, together with a SARS-CoV-2 spike vaccine produced in Spodoptera frugiperda cells and a Chinese hamster ovary cell-produced varicella-zoster virus glycoprotein E vaccine. Site-specific glycan distributions were represented as distribution spectra and compared using NIST MS Search software. Dot-product scores ranging from 0 to 999 quantified similarity. Results: Across measured glycosylation sites, distributions clustered into six recurrent classes. Similarity was high for replicate analyses, conserved influenza components across annual formulations, and matched components from different suppliers within the same production platform (similarity scores = 978, 961, and 960, respectively). Similarity was lower between sites within the same protein, between influenza strains, and between production sources (similarity scores = 554, 540, and 209, respectively). Among production-source comparisons, egg- and Madin–Darby canine kidney-derived profiles were most similar, and the overall ordering of glycosylation similarity was consistent with broad phylogenetic relatedness among production hosts. Conclusions: Distribution spectra-based similarity scoring of vaccine glycoproteins provides a quantitative, reusable approach for documenting site-specific glycosylation microheterogeneity. Using this method, we can conclude that production source is the dominant contributor to variation, whereas replicates, annual formulations, and suppliers within the same production platform are highly consistent. Full article

Theories on the early steps of the HIV-1 life cycle have been radically revised over the past five years. The long-held assumption that the capsid fully disassembles in the cytoplasm has given way to a more nuanced view: Cytoplasmic disassembly does occur and, in several myeloid systems, is increasingly linked to cytosolic cDNA sensing and to abortive infection. However, a substantial fraction of intact or nearly intact capsid cores instead traverse the nuclear pore complex (NPC) and, upon interacting with the host factor CPSF6, induce liquid–liquid phase separation. This leads to the formation of biomolecular condensates, termed HIV-1 membraneless organelles (HIV-1-MLOs), which subsequently merge with nuclear speckles (NSs). In this Perspective we read these condensates along five interlocking axes. First, the virus drives the host phase separation of cleavage and polyadenylation specificity factor 6 (CPSF6), which quickly fuses with another MLO: the NS composed of the speckle scaffold factors, SON and SRRM2. Second, the resulting condensate behaves as a catalytic site that concentrates the reverse-transcription machinery and thereby promotes integration of the viral DNA into speckle-associated chromatin (SPADs). Third, the same compartment is the final layer of a stratified programme of innate immune evasion, shielding nascent double-stranded DNA from cGAS–STING after cytoplasmic restriction factors and sensors have been outmanoeuvred. Fourth, although demonstrated only in vitro, stable HIV-1-MLOs can maintain the viral RNA genome in the presence of a reverse-transcription inhibitor. Upon removal of the inhibitor, reverse transcription resumes, mirroring, to some extent, the situation in individuals undergoing interruption of antiretroviral therapy and suggesting that these structures may act as a pre-integration reservoir. Fifth, and still largely unexplored, the sanctuary has a pharmacological dimension: anatomical lymphoid compartments, and possibly the condensate itself through selective small-molecule partitioning, may limit antiretroviral drug access. We situate HIV-1-MLOs within the convergent condensate strategies of SARS-CoV-2 and other viruses, and we discuss the clinical, diagnostic, therapeutic, and vaccine implications, including capsid inhibitors as “block-and-expose” tools. Full article

Background/Objectives: The lack of effective antiviral therapies for many viral infections highlights the need for the development of new antiviral agents. The broad antiviral effects of glycopeptide antibiotics (GPAs) and their derivatives have been previously described. In our studies, we investigated the in vitro viral inhibitory activity of newly synthesized GPA derivatives against Zika virus (ZIKV), chikungunya virus (CHIKV), o’nyong-nyong virus (ONNV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: Antiviral activity (EC50) and cytotoxicity (CC50) of the active compounds were determined using cell-based assays. The mechanism of action of the lead compound was investigated using binding and entry assays, cell-free virion pre-incubation, a virion destabilization assay, a liposome-based capsid protection assay, and molecular docking analysis. Results: Seven of the compounds were able to inhibit ZIKV and two compounds inhibited all four tested viruses. Among them, a teicoplanin pseudoaglycone derivative, compound 7, showed the strongest antiviral activity, inhibiting all four viruses at low micromolar concentrations. Mechanistic studies demonstrated that compound 7 acts during an early stage of ZIKV infection and inhibits low-pH-triggered virus–liposome fusion. Molecular docking analysis suggested potential interactions between compound 7 and the viral envelope protein that could interfere with the conformational rearrangements required for membrane fusion. Conclusions: The present findings demonstrate that hydrophobic GPA derivatives, particularly compound 7, exhibit promising broad-spectrum antiviral activity in vitro. Whether similar mechanisms contribute to the antiviral activity against other viruses remains unknown. The studied GPA derivatives are promising candidates for further pre-clinical and clinical development as broad-spectrum antivirals. Full article

SARS-CoV-2 infection leads to extrapulmonary complications in multiple organs, including the brain, both in the short-term and long-term. The neurological manifestation of SARS-CoV-2 infection ranges from benign signs like loss of smell and loss of taste to severe complications like encephalitis, stroke, and exacerbation of Alzheimer’s disease (AD) progression. Pericytes are mural cells of the brain vasculature that help maintain the blood–brain barrier (BBB), regulate cerebral blood flow (CBF), modulate neuroinflammation, and clear toxic materials, including amyloid beta. Pericytes express ACE2, the receptor for SARS-CoV-2, and therefore may be targeted by either direct virus infection or virus-induced inflammatory cytokines induced by the virus in the brain. To further study the effects of SARS-CoV-2 on pericytes and BBB integrity, the long-term effects of SARS-CoV-2 infection on brain pericytes, inflammation, and other neuropathological complications were analyzed in mice. K18 (human ACE2 transgenic) mice were infected with 10³ PFU of SARS-CoV-2 (delta strain), and the brains were analyzed at 6, 14, and 30 days post-infection (dpi). A significant reduction in the weight of infected mice was observed by 6 dpi. Viral nucleocapsid protein and infectious SARS-CoV-2 were observed in the brains of all mice by 6 dpi, and in some mice by 14 dpi, but not at 30 dpi. This observation suggests viral neurotropism with subsequent clearance at later timepoints. Despite virus clearance, the levels of inflammatory mediators, including TNF-α and IFN-γ were significantly elevated up to 30 dpi. We also observed a significant reduction in the level of brain pericytes by 14 dpi up to 30 dpi. Importantly, an increase was observed in the level of Friend Leukemia Integration 1 (FLI-1), a transcription factor known to promote pericyte cell death, from 14 dpi up to 30 dpi. The level of amyloid beta 1–42 was elevated in the brain of infected mice at 6 dpi, and this was maintained up to 30 dpi, and there was a decrease in neuronal density from 14 to 30 dpi. Furthermore, we observed an increased expression of Alzheimer’s disease (AD)-associated genes like PSEN1, BACE1, and APP. Furthermore, there was increased activation of several neurodegenerative pathways, including “G alpha (z) signaling pathway”, “Apelin muscle signaling pathway”, and “G beta-gamma (Gβγ) signaling”, in the brains of infected mice compared to control mice. Collectively, the observed neuropathology and unique molecular markers of neurodegenerative disease progression provide a novel mechanism by which COVID-19 may promote dementia/AD by contributing to pericyte loss and BBB dysfunction during infection. Full article

Identifying antigens that elicit protective immunity is the key step for vaccine development. Here, we describe the use of the MS2 VLP platform to identify epitopes of SARS-CoV-2 structural proteins recognized by antibodies from COVID-19 patients, and to present those epitopes to the immune system as vaccines. We constructed an MS2 virus-like particle (VLP) library covering all four structural proteins of SARS-CoV-2 and affinity-selected vaccine candidates by biopanning on antibodies from infected humans. We focused on the structural proteins, reasoning that they are the most likely targets of a protective antibody response. The epitopes we found map almost entirely to the spike and nucleocapsid proteins. The VLPs displaying such epitopes were produced individually in E. coli and then tested for their potential as vaccines. While none of the affinity-selected spike-specific VLPs elicited neutralizing antibodies, VLPs displaying nucleocapsid epitopes induced protective immunity in a hamster model. This work illustrates the MS2 VLP platform’s capacity for the identification of new vaccine candidates and raises the possibility that VLPs displaying nucleocapsid epitopes could provide long-lasting protection against a range of virus variants. Full article

COVID-19, influenza, and respiratory syncytial virus are leading causes of severe acute respiratory infection (SARI). As viral dynamics shift post-pandemic, comparing their clinical profiles is essential for optimizing management and vaccination strategies. We conducted a retrospective observational study of adults hospitalized with PCR-confirmed COVID-19, influenza, or RSV over three consecutive seasons (2021–2024). We compared clinical features, comorbidities and outcomes, including mortality, intubation rates and respiratory deterioration. Multivariable analyses were performed where virus was the independent variable and respiratory deterioration, intubation rate and mortality, Charlson Comorbidity Index, smoking status and pneumonia were co-variates. 263 patients were analyzed. Key findings revealed distinct clinical profiles: influenza patients were significantly younger, while COVID-19 was the predominant cause of viral pneumonia. RSV patients presented with the most severe oxygenation deficit upon admission and experienced the highest rate of respiratory deterioration (28%). Logistic regression analyses demonstrated that pneumonia [OR 2.81, 95% Confidence Interval (CI): 1.23–6.43, p = 0.01] and RSV (OR 2.8, 95% CI: 1.16–6.63, p = 0.02) were independently associated with respiratory deterioration. Similarly, pneumonia (OR 4.86, 95%CI: 1.62–17.36, p < 0.01] and RSV (OR 4.67, 95%CI: 1.5–14.34, p < 0.01) were independently associated with high risk of intubation. Among patients hospitalized because of COVID-19, RSV and Influenza, pneumonia and RSV were linked with respiratory deterioration and increased risk of intubation but not with death. Full article

Background/Objectives: Pediatric acute-onset neuropsychiatric syndrome (PANS) describes the rapid onset of obsessive–compulsive symptoms or severe food restriction, accompanied by neuropsychiatric or somatic features that are not better explained by another disorder. PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections) is a related, more narrowly defined construct in which symptoms are temporally associated with group A Streptococcus infection. This review examines clinical symptoms, infectious associations, proposed immune mechanisms, biomarker limitations, and treatment strategies for infection-associated PANS/PANDAS. Methods: A structured narrative search of PubMed/MEDLINE, Embase, the Cochrane Library, Google Scholar/publisher-indexed literature, ClinicalTrials.gov, and reference lists was performed up to 16 June 2026. Original cohorts, case series, systematic reviews, narrative reviews, consensus guidance, mechanistic studies, and registered prospective studies were prioritized. The review was not designed as a PRISMA-ScR scoping review; however, the methods were expanded to improve transparency and align with SANRA principles. Results: Group A Streptococcus remains the best characterized infectious association, although prospective studies have not uniformly demonstrated a consistent temporal relationship between streptococcal infection and neuropsychiatric exacerbations. Parent-reported surveys and case-based literature also describe temporal associations with Mycoplasma pneumoniae, influenza-like illnesses, upper respiratory infections, Borrelia burgdorferi, Epstein–Barr virus, and SARS-CoV-2. Proposed mechanisms include molecular mimicry, anti-D1R and anti-D2R antibodies, other antineuronal antibodies, calcium/calmodulin-dependent protein kinase II signaling, blood–brain barrier vulnerability, cytokine and Th17 effects, neuroinflammatory amplification, basal ganglia/CSTC circuit dysfunction, and gut–oral–brain immune interactions. None currently provides a definitive diagnostic biomarker. Conclusions: Infection-associated PANS is best approached as a clinically defined, heterogeneous neuroimmune presentation that requires rigorous differential diagnosis, multidisciplinary care, cautious treatment escalation, prospective biomarker validation, and large, multicenter treatment trials. Full article

The inherent genomic plasticity of RNA viruses, particularly influenza viruses and SARS-CoV-2, poses a major obstacle to the establishment of durable herd immunity. This challenge is further compounded by immune imprinting, whereby prior antigenic exposures bias subsequent responses toward previously encountered epitopes at the expense of effective recognition of antigenically drifted variants. In this review, we delineate the mechanistic basis of immune imprinting, with emphasis on the competitive dominance of cross-reactive memory B cells (MBCs). We discuss how the rapid “back-boosting” of these pre-existing clones can limit de novo priming of naïve B cells—through epitope masking and competition for antigen and T follicular helper cell support—thereby diverting germinal center selection and affinity maturation away from variant-specific de novo epitopes and promoting viral immune escape. To address this challenge, this article further reviews the characteristics of immune imprinting responses in influenza viruses, coronaviruses, and dengue virus, as well as corresponding countermeasures, providing a theoretical basis and new avenues for intervention to address immune imprinting induced by rapidly mutating RNA viruses. Full article

The outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as one of the most significant global health crises in recent history. Coronaviruses are a diverse group of RNA viruses classified into alpha, beta, gamma, and delta genera, with SARS-CoV-2 belonging to the beta-coronavirus family. The virus exhibits high transmissibility and causes a wide spectrum of clinical manifestations ranging from mild respiratory symptoms to severe complications such as acute respiratory distress syndrome, multi-organ failure, and death, particularly among elderly and immunocompromised individuals. Structurally, SARS-CoV-2 possesses a large single-stranded RNA genome encoding major structural proteins, including spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins, which play critical roles in host-cell recognition and viral infection. Understanding the molecular mechanisms of virus–host interactions, especially protein–protein interactions (PPIs), is essential for uncovering viral pathogenesis and identifying potential therapeutic targets. Traditional experimental techniques for PPI detection, such as yeast two-hybrid and affinity purification methods, are often expensive, labor-intensive, and prone to inaccuracies. Consequently, computational approaches based on machine learning (ML) and deep learning (DL) have gained significant attention for efficient and scalable PPI prediction. These methods use diverse biological information, including protein sequences, structural features, genomic data, Gene Ontology annotations, and interaction networks, to model complex biological relationships. This survey reviews computational approaches to PPI prediction, highlighting ML- and DL-based techniques, methodological advances, performance evaluation practices, and limitations that affect benchmark comparability. It also discusses biological databases and data sources commonly used in PPI studies and explicitly considers how models trained in coronavirus-centered settings may generalize to other viral families with different mechanisms of host interaction. Full article

Nucleic acid amplification tests (NAATs) are central to modern virology diagnostics. However, evidence supporting alternative specimen types remains uneven across viral families, especially for emerging viruses. This limits diagnostic flexibility in outbreak and clinically complex settings. We conducted a scoping review of NAAT detectability across key body sites for human RNA viruses. PubMed and Embase were systematically searched for studies reporting NAAT results from urine, blood, fecal, cerebrospinal fluid, or respiratory specimens. Data were independently screened and synthesized to summarize specimen-specific detectability for each virus. From 8676 screened records, 321 studies were included, covering 39 viruses across 25 RNA virus families. Detectability across specimen types varied substantially between viruses. Consistent detection across multiple specimens was observed for few viruses, including SARS-CoV-2, Zika virus, and HIV, whereas many emerging viruses were evaluated in a single body compartment with limited comparative data. NAAT performance across specimen types is highly virus-specific and unevenly studied, with reliance on blood or respiratory specimens, potentially overlooking viable, less invasive alternatives. Evidence gaps are particularly pronounced for urine and cerebrospinal fluid, and heterogeneous reporting limits cross-study comparability. Standardized, cross-specimen and longitudinal studies are needed to improve diagnostic strategies, outbreak preparedness, and future assay development. Full article