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With the advent of a variety of vaccines against viral infections, there are multiple viruses that can be prevented via vaccination. However, breakthrough infections or uncovered strains can still cause vaccine-preventable viral infections (VPVIs). Therefore, timely diagnosis, treatment, and surveillance of these viruses is critical to patient care and public health. Point-of-care (POC) viral diagnostics tools have brought significant improvements in the detection and management of VPVIs. These cutting-edge technologies enable prompt and accurate results, enhancing patient care by facilitating timely treatment decisions. This review delves into the advancements in POC testing, including antigen/antibody detection and molecular assays, while focusing on their impact on the diagnosis, treatment, and surveillance of VPVIs such as mpox, viral hepatitis, influenza, flaviviruses (dengue, Zika, and yellow fever virus), and COVID-19. The role of POC tests in monitoring viral infection is crucial for tracking disease progression and managing outbreaks. Furthermore, the application of POC diagnostics has shown to be vital for public health strategies. In this review, we also highlight emerging POC technologies such as CRISPR-based diagnostics and smartphone-integrated POC devices, which have proven particularly beneficial in resource-limited settings. We underscore the importance of continued research to optimize these diagnostic tools for wider global use for mpox, viral hepatitis, influenza, dengue, and COVID-19, while also addressing current challenges related to their sensitivity, specificity, availability, efficiency, and more. Full article

Recent avian influenza outbreaks have heightened global concern over viral threats with the potential to significantly impact human health. Influenza is particularly alarming due to its history of causing pandemics and zoonotic reservoirs. In response, significant progress has been made toward the development of universal influenza vaccines, largely driven by the discovery of broadly neutralising antibodies (bnAbs), which have the potential to neutralise a broad range of influenza viruses, extending beyond the traditional strain-specific response. This could lead to longer-lasting immunity, reducing the need for seasonal vaccinations, and improve preparedness for future pandemics. This review offers a comprehensive analysis of these antibodies, their application in clinical studies, and both their potential and possible shortcomings in managing future influenza outbreaks. Full article

Madin–Darby Canine Kidney (MDCK) cells are a key cell line for influenza vaccine production, due to their high viral yield and low mutation resistance. In our laboratory, we established a tertiary cell bank (called M60) using a standard MDCK cell line imported from American Type Culture Collection (ATCC) in the USA. Due to their controversial tumourigenicity, we domesticated non-tumourigenic MDCK cells (named CL23) for influenza vaccine production via monoclonal screening in the early stage of this study, and the screened CL23 cells were characterised based on their low proliferative capacity, which had certain limitations in terms of expanding their production during cell resuscitation. It was thus our objective to enhance the proliferation efficiency of MDCK cells for influenza vaccine production following cell resuscitation, with a view to improving the production of non-tumourigenic MDCK cells for vaccines and enhancing the production of influenza virus lysate vaccines from MDCK cells through genetic intervention. We concentrated on the protein thrombosponin-1 (THBS1), which was markedly differentiated in the proteomics data of the two MDCK cells. By integrating this finding with related studies, we were able to ascertain that THBS1 exerts a significant influence on the level of cell proliferation and apoptosis. Consequently, our objective was to investigate the impact of THBS1 expression on MDCK cell apoptosis by verifying the differences in THBS1 expression between the two MDCK cells and by interfering with THBS1 expression in the MDCK cells. We found that the knockdown of THBS1 significantly increased the proliferation and apoptosis of CL23 cells without causing significant changes in cell migration and invasion, and its overexpression significantly decreased the proliferation of M60 cells and increased cell migration, invasion, and apoptosis. In addition, the TGF-β/Smad pathway target genes transforming growth factor-β1 (TGF-β1), mothers against decapentaplegic homolog 2 (Smad2), and mothers against decapentaplegic homolog 3 (Smad3), were significantly down-regulated in CL23 cells after THBS1 knockdown and up-regulated in M60 cells after overexpression, with consistent expression identified at both the mRNA and protein levels. The treatment of cells with TGF-β activators and inhibitors further demonstrated that THBS1 regulated MDCK cell proliferation and apoptosis through the TGF-β/Smad signalling pathway. Finally, we found that THBS1 also regulated H1N1 influenza virus replication. These findings enable a comprehensive understanding of the regulatory mechanisms of THBS1 regarding MDCK cell proliferation and apoptosis functions and the effects of influenza virus replication. Full article

Background/Objectives: Vaccines have been recognized as one of the most effective public health interventions. However, vaccine-associated anaphylaxis, although rare, is a serious adverse reaction. The incidence of anaphylaxis related to non-COVID-19 vaccines in adults remains underreported. This systematic review and meta-analysis aim to estimate the incidence of post-vaccination anaphylaxis across various vaccines in adults. Methods: A comprehensive literature search of PubMed, Embase, Scopus, and Web of Science identified studies on anaphylaxis following vaccination in adults (≥18 years), excluding COVID-19 vaccines. PRISMA 2020 guidelines were followed. The protocol was registered in PROSPERO in advance (ID CRD42024566928). Random-effects and fixed-effects models were used to pool data and estimate the logit proportion, with the logit-transformed proportion serving as the effect size, thereby allowing for the calculation of event rates. Results: A total of 37 studies were included in the systematic review, with 22 studies contributing to the meta-analysis, representing a combined population of 206,855,261 participants. Most studies focused on influenza vaccines (n = 15). Across all studies, 262 anaphylactic cases were reported, with 153 cases related to influenza vaccines, followed by herpes zoster virus vaccines (38 cases) and yellow fever vaccines (29 cases). Td/Tdap vaccine had the lowest rate (0.0001 per 100,000 participants). The overall random-effects model yielded a logit proportion of −10.45 (95% CI: −12.09 to −8.82, p < 0.001), corresponding to an event rate of 2.91 events per 100,000 subjects (95% CI: 0.56 to 14.73). Sensitivity analysis showed a higher incidence for influenza, hepatitis vaccines, and in vulnerable populations. Conclusions: Anaphylaxis following vaccination in adults is rare but varies by vaccine type. Strengthened monitoring and preparedness are essential, especially in non-medical settings, to ensure a rapid response to anaphylaxis and maintain public confidence in vaccination programs. Full article

Background and Objectives: Three respiratory syncytial virus (RSV) vaccines have been recently made available for older adults. Understanding the principal characteristics of the first vaccine-takers can pave the way for a successful vaccination campaign. The objective of this study was to explore the sociodemographic and clinical characteristics of the first Italian users of an adjuvanted RSV vaccine and their attitudes towards RSV and vaccination. Materials and Methods: This cross-sectional study was conducted in 2024 in Liguria (Italy). Individuals aged ≥60 years with no contraindications to the adjuvanted vaccine RSVPreF3 OA were eligible. Following vaccination, subjects filled in a questionnaire, which comprised items on sociodemographic and clinical characteristics, attitudes towards RSV and RSV vaccination and a vaccination trust indicator (VTI). Results: A total of 453 vaccinees completed the survey. Their mean age was 74.9 ± 8.0 years, and 50.6% were males. Nine of ten (89.2%) individuals had ≥1 co-morbidity, of which cardiovascular conditions (70.4%), respiratory diseases (27.6%) and diabetes (18.5%) were the most common. Uptake of the routine vaccines was high: 91.2% and 98.7% received the 2023/2024 season influenza and ≥2 COVID-19 vaccines, respectively. The most common reasons for the current RSV vaccination were general practitioner advice (43.9%), followed by the willingness to be protected against (20.8%) and feelings of being at risk (16.6%) of RSV. The average VTI score was 91.5%, suggesting high trust in vaccines. More positive attitudes towards RSV vaccination were observed (p < 0.01) among subjects who received more COVID-19 vaccine doses, whose reasons for the current RSV vaccination were the willingness to be protected or to be in good health and the feeling of being at risk for RSV. Conclusions: The first Italian users of the novel RSVPreF3 OA vaccine were represented by high-risk individuals with a comparatively high prevalence of co-morbidities, high uptake of the seasonal respiratory vaccines and high trust in immunization. Full article

Acute respiratory infections are a significant challenge in primary care and hospital settings. Viruses are the most common etiology and the overlapping symptomatology among major respiratory viruses, such as influenza, severe acute respiratory syndrome coronavirus 2, and respiratory syncytial virus, requires the use of diagnostic tests that deliver early and accurate results. With the increasing availability of rapid antigen tests (RATS), it is tempting to prefer them over polymerase chain reaction (PCR) tests. However, compelling arguments support the existing recommendations in some European countries to maintain PCR testing for patient management throughout the year. RATs show sensitivities below 30% with lower viral loads, which are common and can have significant clinical implications. RATs perform well at lower cycle threshold (Ct) values, with sensitivity reaching 97.9% for Ct values below 20, which drops significantly for values above 25. Factors affecting viral load include disease stage, vaccination status, and viral variants, all of which can compromise the accuracy of antigen tests. Multi-target PCR tests effectively overcome these issues, ensuring reliable diagnosis. Additionally, the early detection of paucisymptomatic cases is essential in primary care and hospital settings to facilitate isolation and prevent secondary infections. Economic analyses support the use of comprehensive PCR tests, such as triplex-type tests, detecting SARS-CoV-2, influenza viruses, and RSV, as a first-line approach, as they can reduce case numbers and healthcare resource utilization. Maintaining PCR testing year-round is therefore crucial for the effective management of respiratory infections. Full article

Poultry production systems are usually exposed to important infections that could be prevented by vaccination programs. Conventional methods of vaccination such as drinking water; spray, eye, or nose inoculation; and injection are usually given after hatching and have many disadvantages. Therefore, there is a great need for searching of alternative ways for vaccination process. In ovo vaccination technology is now regarded as an alternative approach to post-hatch vaccination in modern poultry operations. This technique is effective, fast, provides uniform vaccine dosing and delivery, is suitable for massive production, and reduces labor costs. Routine in ovo vaccination is applied during the late stage of embryonic development between days 17.5 and 19.25 of egg incubation. The best route of inoculation of the vaccine is in the amniotic fluid or in the embryo’s muscles, without causing any hatchability or chick quality losses. Accordingly, the inoculation site, the age of the embryos and breeders, presence of maternal antibodies, and the sanitation of equipment’s and the environment during the vaccination process affect the efficiency of the in ovo vaccination technique. In ovo vaccination technology is currently applied for vaccination against several economically important viral diseases such as Newcastle, infectious bursal disease, Marek’s disease, infectious laryngotracheitis, infectious bronchitis, avian influenza, and avian metapneumovirus. Moreover, vaccines used for prevention of mycoplasmosis and coccidiosis could be applied in ovo instead of in post-hatching application. It can be concluded that in ovo vaccination is a rapidly growing trend of vaccine technology, and it can replace post-hatching vaccination conventional methods. Full article

Background/Objective: Highly pathogenic (HP) H5Nx and low-pathogenicity (LP) H9N2 avian influenza viruses (AIVs) pose global threats to the poultry industry and public health, highlighting the critical need for a dual-protective vaccine. Methods: In this study, we generated a model PR8-derived recombinant H5N2 vaccine strain with hemagglutinin (HA) and neuraminidase (NA) genes from clade 2.3.2.1c H5N1 and Y439-like H9N2 viruses, respectively. To enhance the immunogenicity of the recombinant H5N2 vaccine strain, N-glycans of the HA2 subunit, NA, and M2e were modified. Additionally, we replaced M2e with avian M2e to enhance the antigenic homogeneity of AIVs for better protection. We also replaced PR8 PB2 with 01310 PB2, which is the PB2 gene derived from an LP H9N2 avian influenza virus, to eliminate pathogenicity in mammals. The productivity of the model vaccine strain (rvH5N2-aM2e-vPB2) in embryonated chicken eggs (ECEs), its potential risk of mammalian infection, and the immunogenicity associated with different inactivation methods (formaldehyde (F/A) vs. binary ethyleneimine (BEI)) were evaluated. Results: The rvH5N2-aM2e-vPB2 strain demonstrated high productivity in ECEs and exhibited complete inhibition of replication in mammalian cells. Furthermore, compared with using F/A inactivation, inactivation using BEI significantly enhanced the immune response, particularly against NA. This enhancement resulted in increased virus neutralization titers, supporting its efficacy for dual protection against H5Nx and H9N2 avian influenza viruses. Furthermore, we demonstrated that M2e-specific immune responses, difficult to induce with inactivated vaccines, can be effectively elicited with live vaccines, suggesting a strategy to enhance M2e immunogenicity in whole influenza virus vaccines. Conclusions: Finally, the successful development of the model rH5N2 vaccine strain is described; this strain provides dual protection, has potential applicability in regions where avian influenza is endemic, and can be used to promote the development of versatile H5N2 recombinant vaccines for effective avian influenza control. Full article

Background: Acute disseminated encephalomyelitis (ADEM) is a rare, immune-mediated inflammatory disorder of the central nervous system (CNS), typically characterized by the acute onset of multifocal demyelination. The pathogenesis of ADEM remains unclear, but it is believed to be triggered by an autoimmune response, often following viral infections or vaccinations. Case report: This case report describes a 3-year-old child who developed ADEM after receiving two concurrent influenza vaccines: one for seasonal influenza and one for the 2009 H1N1 pandemic. The patient presented with motor regression, mild pleocytosis in cerebrospinal fluid (CSF), and typical MRI findings of ADEM. Steroid pulse therapy resulted in rapid improvement, and the patient recovered fully without sequelae. Results: Although the influenza vaccine has been linked to ADEM in some studies, it remains uncertain whether the simultaneous administration of both vaccines contributed to the onset of ADEM. While influenza vaccines are considered safe and effective by health organizations such as the CDC, data suggest that the incidence of ADEM and other neurological complications is significantly higher after natural influenza infections compared to vaccination. This highlights the importance of vaccination in preventing severe outcomes. Conclusions: This case underscores the importance of monitoring and reporting adverse events following vaccination to refine our understanding of rare complications like ADEM. While simultaneous vaccine administration warrants further research, the benefits of vaccination in preventing severe complications from natural infections far outweigh the risks. Continued vigilance and improved surveillance systems are essential for maintaining public confidence in vaccination programs. Full article

Background: Influenza and pneumococcal vaccinations play a crucial role in disease prevention among older adults and are recommended to older adults aged 60 years and over in China, but the vaccination rates are suboptimal. Behavioral spillover indicates that a change in one behavior may lead to changes in other related behaviors. Objective: Based on the Behavioral Spillover Theory, this study aimed to investigate the association between influenza vaccination history and pneumococcal vaccination intention, as well as the mediating role of negative attitudes toward general vaccination among older adults in China. Method: A multi-center cross-sectional survey was conducted among 1031 older adults, and 658 participants (median age: 65.0 ± 9.0 years) who had not received pneumococcal vaccination were included in the analysis. Correlation analysis and path analysis were performed. Results: A significant positive association was observed between influenza vaccination history and pneumococcal vaccination intention (r = 0.167, p < 0.001). In contrast, negative attitudes toward general vaccination, including mistrust of vaccine benefits (r = −0.253, p < 0.001), worries about unforeseen future effects (r = −0.180, p < 0.001), concerns about commercial profiteering (r = −0.360, p < 0.001), and a preference for natural immunity (r = −0.212, p < 0.001) were negatively associated with pneumococcal vaccination intention. Negative attitudes toward general vaccination mediated the association between influenza vaccination history and pneumococcal vaccination intention (total indirect effect = 0.119, p < 0.001, effect size = 50.0%). Conclusion: These findings demonstrated that influenza vaccination history may reduce negative attitudes toward general vaccination, which may further increase pneumococcal vaccination intention, indicating spillover effects of influenza vaccination history. To promote vaccination behavior among older adults, addressing negative attitudes toward general vaccination is crucial. Full article

Background/Objectives: Intranasal vaccination enhances protection against respiratory viruses by providing stimuli to the immune system at the primary site of infection, promoting a balanced and effective response. Influenza vectors with truncated NS1 are a promising vaccine approach that ensures a pronounced local CD8+ T-cellular immune response. Here, we describe the protective and immunomodulating properties of an influenza vector FluVec-N carrying the C-terminal fragment of the SARS-CoV-2 nucleoprotein within a truncated NS1 open reading frame. Methods: We generated several FluVec-N recombinant vectors by reverse genetics and confirmed the vector’s genetic stability, antigen expression in vitro, attenuation, and immunogenicity in a mouse model. We tested the protective potential of FluVec-N intranasal immunization in naïve mice and seropositive Th2-prone mice, primed with aluminium-adjuvanted inactivated SARS-CoV-2. Immune response in immunized and challenged mice was analyzed through serological methods and flow cytometry. Results: Double intranasal immunization of naïve mice with FluVec-N reduced weight loss and viral load in the lungs following infection with the SARS-CoV-2 beta variant. Mice primed with alum-adjuvanted inactivated coronavirus experienced substantial early weight loss and eosinophilia in the lungs during infection, demonstrating signs of enhanced disease. A single intranasal boost immunization with FluVec-N prevented the disease enhancement in primed mice by modulating the local immune response. Protection was associated with the formation of specific IgA and the early activation of virus-specific effector and resident CD8+ lymphocytes in mouse lungs. Conclusions: Our study supports the potential of immunization with influenza vector vaccines to prevent respiratory diseases and associated immunopathology. Full article

Bone marrow stromal antigen 2 (BST2) is a host-restriction factor that plays multiple roles in the antiviral defense of innate immune responses, including the inhibition of viral particle release from virus-infected cells. BST2 may also be involved in the endothelial adhesion and migration of monocytes, but its importance in the immune system is still unclear. Immune cell adhesion and migration are closely related to the initiation of immune responses. In this study, we found that the expressions of the lymph node homing marker chemokine receptor 7 (CCR7) and an adhesion molecule intercellular adhesion molecule 1 (ICAM-1) in conventional dendritic cells (cDCs) were associated with BST2 expression. Interestingly, Bst2^−/− cDCs showed lower chemotactic ability, including velocity and accumulative distance toward chemokine ligand 19 (CCL19) gradient in vitro, compared to wild-type cDCs. Bst2^−/− cDCs also showed reduced migration and reduced retention capacity in draining lymph nodes in vivo. As a result, Bst2^−/− cDCs as antigen-presenting cells induced lower antigen-specific B cell and T cell responses compared to Bst2^+/+ cDCs. Notably, mice administered the influenza vaccine via Bst2^−/− cDCs exhibited substantially inefficient virus clearance compared to mice administered the Bst2^+/+ cDCs vaccine. Therefore, we propose that BST2, which plays a critical role in the effective migration and retention of cDCs, is involved in the development of optimal immunological effects in draining lymph nodes. Full article

Background/Objectives: Seasonal influenza is a significant global health concern, causing substantial morbidity and mortality, particularly among high-risk groups such as children under five years old. There is scarce local evidence from developing countries such as Jordan on the burden of influenza, which has limited preventive measures. This multi-center national cross-sectional study aimed to assess the epidemiological and clinical burden of influenza among hospitalized children under five years old in Jordan. Methods: Data were collected from 1000 participants across four hospitals between November 2022 and April 2023. Nasopharyngeal specimens were analyzed using multiplex RT-PCR to determine positivity for influenza A and B. Results: We found a 9.9% positivity rate, predominantly influenza A (8.4%), while influenza B was positive among 1.5% of the participants. Positivity rates were higher in older age groups, particularly children older than 2 years. Influenza-positive cases exhibited longer fever durations and higher rates of sore throat. There were no positive influenza cases among participants if they or any of their family members received the influenza vaccine, highlighting the vaccine’s protective role. Logistic regression analysis identified maternal smoking during pregnancy as a significant predictor of influenza positivity. Conclusions: The findings of this study underscore the need for enhanced vaccination efforts and public health policies targeting young children and pregnant women in Jordan. Expanding vaccination uptake could significantly mitigate the burden of influenza and its complications in this vulnerable population. Full article

Background/Objectives: The H7N9 avian influenza virus (AIV) constitutes a novel subtype of influenza virus that has emerged within the past decade. Empirical studies have demonstrated that H7N9 AIV holds the potential to trigger a human pandemic. Vaccines constitute the sole armament available to humanity in combating influenza epidemics. DNA vaccines present numerous merits; however, substantial conundrums persist regarding how to augment their immunogenicity and implement their delivery through mucosal immunization. Methods: In this study; BALB/c mice were utilized as a model to investigate the effect of CCL19 as a molecular adjuvant and to determine the immune response elicited by polyethylene imine (PEI) and chitosan (CS) as adjuvants during the delivery of a DNA vaccine through the nasal mucosal route. Results: Our results revealed that the CCL19 molecular adjuvant exerts a substantial immunomodulatory enhancement effect on the H7N9-HA DNA vaccine, inducing more pronounced cellular and humoral immunity. Additionally, our results indicated that the composite formed by the HA-CCL19 DNA in combination with PEI and CS effectively activates local mucosal immunity as well as systemic humoral and cellular immunity, offering 100% protection against lethal doses of homologous virus challenges. Conclusions: CCL19 conspicuously augments the immunogenicity of the influenza virus HA DNA and conserves the integrity of the vaccine antigen. Simultaneously, CS and PEI proficiently facilitate the mucosal delivery of DNA, thereby eliciting mucosal immunity related to DNA vaccines. This study investigated the feasibility of utilizing nasal mucosa for DNA vaccine immunization, which holds significant implications for the advancement and application of DNA vaccines in public health Full article

Background: The influenza virus’s high mutation rate requires the annual reformulation and administration of the vaccine. Therefore, its vaccine effectiveness (VE) must be evaluated annually. Aim: Estimate the effectiveness of the influenza vaccine and analyze the impact of age, seasonal variations, and the vaccination to sample collection interval on VE. Methods: The study used a test-negative case–control (TNCC) design to collect data from patients under 18 years of age who presented with acute respiratory infection (ARI) symptoms and underwent influenza virus testing at a national children’s regional medical center in Guangdong Province between October 2021 and January 2024, spanning three influenza seasons. VE was estimated using unconditional logistic regression. Results: A total of 27,670 patient data entries were analyzed. The VE against all influenza viruses across the three seasons was 37% (95% CI: 31–43), with the lowest VE of 24% (95% CI: 8–37) observed in the 2021–2022 season. In children aged 0.5 to <3 years, the VE was 32% (95% CI: 19–43). The effectiveness for samples collected at intervals of 0.5–2 months, 3–6 months, and over 6 months after vaccination was 39% (95% CI: 32–46), 30% (95% CI: 19–40), and 28% (95% CI: 5–46). Conclusions: Across three influenza seasons, at least one-third of vaccinated individuals were protected from influenza in outpatient settings. Given that children are at high risk, improving vaccination management is recommended, and parents should be encouraged to vaccinate their children before each influenza season. Full article