A rapid and highly sensitive multiple detection of human adenovirus type 3, type 7 and respiratory syncytial virus by recombinase-aided reverse transcription PCR.

BACKGROUND: Polymerase chain reaction (PCR) has been widely used for many pathogen detection. However, PCR technology still suffers from long detection time and insufficient sensitivity. Recombinase-aided amplification (RAA) is a powerful nucleic acid detection tool with high sensitivity and amplification efficiency, but its complex probes and inability of multiplex detection hinder the further application of this technology. METHODS: In this study, we developed and validated the multiplex reverse transcription recombinase-aided PCR (multiplex RT-RAP) assay for human adenovirus 3 (HADV3), human adenovirus 7 (HADV7), and human respiratory syncytial virus (HRSV) within 1 h with Human RNaseP protein as a reference gene to monitor the whole process. RESULTS: Using recombinant plasmids, the sensitivity of multiplex RT-RAP for the detection of HADV3, HADV7, and HRSV was 18, 3, and 18 copies per reaction, respectively. The multiplex RT-RAP showed no cross-reactivity with other respiratory viruses, demonstrating its good specificity. A total of 252 clinical specimens were tested by multiplex RT-RAP and the results were found to be consistent with those of corresponding RT-qPCR assays. After testing serial dilutions of selected positive specimens, the detection sensitivity of multiplex RT-RAP was two to eightfold higher than that of corresponding RT-qPCR. CONCLUSION: We conclude the multiplex RT-RAP is a robust, rapid, highly sensitive, and specific assay with the potential to be used in the screening of clinical samples with low viral load.

Respiratory syncytial virus surge in 2022 caused by lineages already present before the COVID-19 pandemic.

In 2022, Austria experienced a severe respiratory syncytial virus (RSV) epidemic with an earlier-than-usual start (Weeks 35/2021-45/2022) and increased numbers of pediatric patients in emergency departments. This surge came 2 years after a season with no cases detected as a result of coronavirus disease 2019 nonpharmaceutical interventions. We analyzed epidemiologic patterns and the phylodynamics of RSV based on approximately 30 800 respiratory specimens collected year-round over 10 years from ambulatory and hospitalized patients from 248 locations in Austria. Genomic surveillance and phylogenetic analysis of 186 RSV-A and 187 RSV-B partial glycoprotein sequences collected from 2018 to 2022 revealed that the 2022/2023 surge was driven by RSV-B in contrast to the surge in the 2021/2022 season that was driven by RSV-A. Whole-genome sequencing and phylodynamic analysis indicated that the RSV-B strain GB5.0.6a was the predominant genotype in the 2022/2023 season and emerged in late 2019. The results provide insight into RSV evolution and epidemiology that will be applicable to future monitoring efforts with the advent of novel vaccines and therapeutics.

Current regulatory landscape for viral point-of-care testing in the United States.

Historically, the diagnosis of viral infections has been accomplished using a combination of laboratory-based methods, including culture, serology, antigen-based tests, and molecular (e.g., real-time PCR) assays. Although these methods provide an accurate way to detect viral pathogens, testing in a centralized laboratory may delay results, which could impact patient diagnosis and management. Point-of-care tests, including antigen- and molecular-based assays, have been developed to assist with the timely diagnosis of several viral infections, such as influenza, respiratory syncytial virus, and COVID-19. Despite the ability of point-of-care tests to provide rapid results (i.e., <30 min), there are issues to consider prior to their routine use, including test performance and specific regulatory requirements. This review will provide a summary of the regulatory landscape of point-of-care tests for viral infections in the United States, and address important considerations such as site certification, training and inspection readiness.

In-Depth Analysis of the Re-Emergence of Respiratory Syncytial Virus at a Tertiary Care Hospital in Germany in the Summer of 2021 after the Alleviation of Non-Pharmaceutical Interventions Due to the SARS-CoV-2 Pandemic.

Following the extensive non-pharmaceutical interventions (NPIs) and behavioral changes in the wake of the SARS-CoV-2 pandemic, an interseasonal rise in respiratory syncytial virus (RSV) cases was observed in Germany in 2021. The aim of this study was to characterize the local molecular epidemiology of RSV infections in comparison to the three pre-pandemic seasons. Additionally, clinical data were retrieved from patient charts to determine the clinical significance of RSV infections. RSV detections peaked in calendar week 40 of 2021, 18 weeks earlier than the usual peak observed in the three pre-pandemic seasons. Sequence analysis revealed a close phylogenetic relatedness regardless of the season of origin. A significantly higher amount of pediatric cases (88.9% of all cases, p < 0.001) was observed for season 2021/2022. For the pediatric cases, significant differences were observed for an increased number of siblings in the household (p = 0.004), a lower rate of fever (p = 0.007), and a reduced amount of co-infections (p = 0.001). Although the mean age of the adult patients was significantly younger (47.1 vs. 64.7, p < 0.001), high rates of comorbidities, lower respiratory tract infections and intensive care unit admissions prevailed. The NPIs in the wake of the SARS-CoV-2 pandemic had a tremendous impact on the epidemiologic characteristics and seasonality of RSV and warrant further epidemiologic studies of this important pathogen.

Epidemiology of Human Parainfluenza Virus Type 3 and Respiratory Syncytial Virus Infections in the Time of Coronavirus Disease 2019: Findings From a Household Cohort in Maryland.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, human parainfluenza type 3 (HPIV-3) and respiratory syncytial virus (RSV) circulation increased as nonpharmaceutical interventions were relaxed. Using data from 175 households (n = 690 members) followed between November 2020 and October 2021, we characterized HPIV-3 and RSV epidemiology in children aged 0-4 years and their households. METHODS: Households with ≥1 child aged 0-4 years were enrolled; members collected weekly nasal swabs (NS) and additional NS with respiratory illnesses (RI). We tested NS from RI episodes in children aged 0-4 years for HPIV-3, RSV, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using reverse-transcriptase polymerase chain reaction (RT-PCR). Among children with HPIV-3 or RSV infection, we tested contemporaneous NS from household members. We compared incidence rates (IRs) of RI with each virus during epidemic periods and identified household primary cases (the earliest detected household infection), and associated community exposures. RESULTS: 41 of 175 (23.4%) households had individuals with HPIV-3 (n = 45) or RSV (n = 46) infections. Among children aged 0-4 years, RI IRs /1000 person-weeks were 8.7 [6.0, 12.2] for HPIV-3, 7.6 [4.8, 11.4] for RSV, and 1.9 [1.0, 3.5] for SARS-CoV-2. Children aged 0-4 years accounted for 35 of 36 primary HPIV-3 or RSV cases. Children attending childcare or preschool had higher odds of primary infection (odds ratio, 10.81; 95% confidence interval, 3.14-37.23). CONCLUSIONS: Among children aged 0-4 years, RI IRs for HPIV-3 and RSV infection were 4-fold higher than for SARS-CoV-2 during epidemic periods. HPIV-3 and RSV were almost exclusively introduced into households by young children.

Parainfluenza virus 5 is a next-generation vaccine vector for human infectious pathogens.

Parainfluenza virus 5 (PIV5) is a negative-sense, single-stranded RNA virus that can infect humans and many species of animals. Infection in these reservoir hosts is generally asymptomatic and has few safety concerns. Emerging evidence has shown that PIV5 is a promising vector for developing vaccines against human infectious diseases caused by coronaviruses, influenza, respiratory syncytial virus, rabies, HIV, or bacteria. In this review, we summarize recent progress and highlight the advantages and strategies of PIV5 as a vaccine vector to improve future vaccine design and application for clinical trials.

Genomic Characterization of Respiratory Syncytial Virus during 2022-23 Outbreak, Washington, USA.

We sequenced 54 respiratory syncytial virus (RSV) genomes collected during 2021-22 and 2022-23 outbreaks in Washington, USA, to determine the origin of increased RSV cases. Detected RSV strains have been spreading for >10 years, suggesting a role for diminished population immunity from low RSV exposure during the COVID-19 pandemic.

Epidemiology and molecular characteristics of respiratory syncytial virus (RSV) among italian community-dwelling adults, 2021/22 season.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infections worldwide. While historically RSV research has been focused on children, data on RSV infection in adults are limited. The goal of this study was to establish the prevalence of RSV in community-dwelling Italian adults and analyze its genetic variability during the 2021/22 winter season. METHODS: In this cross-sectional study, a random sample of naso-/oropharyngeal specimens from symptomatic adults seeking for SARS-CoV-2 molecular testing between December 2021 and March 2022 were tested for RSV and other respiratory pathogens by means of reverse-transcription polymerase chain reaction. RSV-positive samples were further molecularly characterized by sequence analysis. RESULTS: Of 1,213 samples tested, 1.6% (95% CI: 0.9-2.4%) were positive for RSV and subgroups A (44.4%) and B (55.6%) were identified in similar proportions. The epidemic peak occurred in December 2021, when the RSV prevalence was as high as 4.6% (95% CI: 2.2-8.3%). The prevalence of RSV detection was similar (p = 0.64) to that of influenza virus (1.9%). All RSV A and B strains belonged to the ON1 and BA genotypes, respectively. Most (72.2%) RSV-positive samples were also positive for other pathogens being SARS-CoV-2, Streptococcus pneumoniae and rhinovirus the most frequent. RSV load was significantly higher among mono-detections than co-detections. CONCLUSION: During the 2021/22 winter season, characterized by the predominant circulation of SARS-CoV-2 and some non-pharmaceutical containment measures still in place, a substantial proportion of Italian adults tested positive for genetically diversified strains of both RSV subtypes. In view of the upcoming registration of vaccines, establishment of the National RSV surveillance system is urgently needed.

Viral co-infection with human respiratory syncytial virus in suspected acute and severe respiratory tract infections during COVID-19 pandemic in Yaoundé, Cameroon, 2020-2021.

BACKGROUND: Acute lower respiratory tract infections (ALRIs) are one one of the leading causes of morbidity and mortality among people of all ages worldwide, particularly in low- and middle-income countries (LMICs). The purpose of this study was to determine epidemiological characteristics of respiratory viruses in acute respiratory infection (ARI) patients during the COVID-19 pandemic in Yaoundé, Cameroon. METHODS: Patients were monitored for respiratory symptoms as part of the surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory viral infections. Patients of all ages with respiratory symptoms less than 5 days were considered. Sociodemographic and clinical data as well as nasopharyngeal samples was collected from patients. Nasopharyngeal samples were tested for SARS-CoV-2, influenza, and respiratory syncytial virus (RSV) using real-time reverse-transcription polymerase chain reaction methods. Virus distribution and demographic data were analyzed with R version 2.15.1. RESULTS: From July 2020 to October 2021, 1120 patients were included. The overall viral detection rate was 32.5%, including 9.5% for RSV, 12.6% for influenza virus and 12.8% for SARS-CoV-2. Co-infections were detected in 6.9% of positive cases. While RSV and influenza virus showed seasonal trends, SARS-CoV-2 was detected throughout the study period. CONCLUSION: We found that during COVID-19 pandemic, respiratory viruses play an important role in etiology of influenza-like illness in Cameroon, and this observation was true for patients of all ages.

Comparison of common human respiratory pathogens among hospitalized children aged ≤ 6 years in Hainan Island, China, during spring and early summer in 2019-2021.

The coronavirus disease 2019 (COVID-19) pandemic and related public health intervention measures have been reported to have resulted in the reduction of infections caused by influenza viruses and other common respiratory viruses. However, the influence may be varied in areas that have different ecological, economic, and social conditions. This study investigated the changing epidemiology of 8 common respiratory pathogens, including Influenza A (IFVA), Influenza B (IFVB), Respiratory syncytial virus (HRSV), rhinovirus (RV), Human metapneumovirus Adenovirus, Human bocavirus, and Mycoplasma pneumoniae, among hospitalized children during spring and early summer in 2019-2021 in two hospitals in Hainan Island, China, in the COVID-19 pandemic era. The results revealed a significant reduction in the prevalence of IFVA and IFVB in 2020 and 2021 than in 2019, whereas the prevalence of HRSV increased, and it became the dominant viral pathogen in 2021. RV was one of the leading pathogens in the 3 year period, where no significant difference was observed. Phylogenetic analysis revealed close relationships among the circulating respiratory viruses. Large scale studies are needed to study the changing epidemiology of seasonal respiratory viruses to inform responses to future respiratory virus pandemics.

Respiratory syncytial virus infection in the modern era.

PURPOSE OF REVIEW: Respiratory syncytial virus (RSV) continues to be a major cause of severe lower respiratory tract infection in infants, young children, and older adults. In this review, changes in the epidemiology of RSV during the coronavirus disease 2019 (COVID-19) pandemic are highlighted together with the role which increased molecular surveillance efforts will have in future in assessing the efficacy of vaccines and therapeutics. RECENT FINDINGS: The introduction of nonpharmaceutical intervention (NPIs) strategies during the COVID-19 pandemic between 2020 and 2022 resulted in worldwide disruption to the epidemiology of RSV infections, especially with respect to the timing and peak case rate of annual epidemics. Increased use of whole genome sequencing along with efforts to better standardize the nomenclature of RSV strains and discrimination of RSV genotypes will support increased monitoring of relevant antigenic sites in the viral glycoproteins. Several RSV vaccine candidates based on subunit, viral vectors, nucleic acid, or live attenuated virus strategies have shown efficacy in Phase 2 or 3 clinical trials with vaccines using RSVpreF protein currently the closest to approval and use in high-risk populations. Finally, the recent approval and future use of the extended half-life human monoclonal antibody Nirsevimab will also help to alleviate the morbidity and mortality burden caused by annual epidemics of RSV infections. SUMMARY: The ongoing expansion and wider coordination of RSV molecular surveillance efforts via whole genome sequencing will be crucial for future monitoring of the efficacy of a new generation of vaccines and therapeutics.

Wastewater concentrations of human influenza, metapneumovirus, parainfluenza, respiratory syncytial virus, rhinovirus, and seasonal coronavirus nucleic-acids during the COVID-19 pandemic: a surveillance study.

BACKGROUND: Respiratory disease is a major cause of morbidity and mortality; however, surveillance for circulating respiratory viruses is passive and biased. Wastewater-based epidemiology has been used to understand SARS-CoV-2, influenza A, and respiratory syncytial virus (RSV) infection rates at a community level but has not been used to investigate other respiratory viruses. We aimed to use wastewater-based epidemiology to understand community viral respiratory infection occurrence. METHODS: A retrospective wastewater-based epidemiology surveillance study was carried out at a large wastewater treatment plant located in California, USA. Using droplet digital RT-PCR, we measured RNA concentrations of influenza A and influenza B viruses, RSV A and RSV B, parainfluenza (1-4) viruses, rhinovirus, seasonal coronaviruses, and metapneumovirus in wastewater solids three times per week for 17 months (216 samples) between Feb 1, 2021, and June 21, 2022. Novel probe-based RT-PCR assays for non-influenza viral targets were developed and validated. We compared viral RNA concentrations to positivity rates for viral infections from clinical specimens submitted to California Sentinel Clinical Laboratories (sentinel laboratories) to assess concordance between the two datasets. FINDINGS: We detected RNA from all tested viruses in wastewater solids. Human rhinovirus (median concentration 4300 [0-9500] copies per gram dry weight) and seasonal human coronaviruses (35 000 [17 000-56 000]) were found at the highest concentrations. Concentrations of viral RNA correlated significantly and positively with positivity rates of associated viral diseases from sentinel laboratories (tau 0·32-0·57, p<0·0009); the only exceptions were influenza B and RSV A, which were rarely detected in wastewater solids. Measurements from wastewater indicated coronavirus OC43 dominated the seasonal human coronavirus infections whereas parainfluenza 3 dominated among parainfluenza infections during the study period. Concentrations of all tested viral RNA decreased noticeably after the omicron BA.1 surge suggesting a connection between changes in human behaviour during the surge and transmission of all respiratory viruses. INTERPRETATION: Wastewater-based epidemiology can be used to obtain information on circulation of respiratory viruses at a localised, community level without the need to test many individuals because a single sample of wastewater represents the entire contributing community. Results from wastewater can be available within 24 h of sample collection, generating real time information to inform public health responses, clinical decision making, and individual behaviour modifications. FUNDING: CDC Foundation.

Impact of the COVID-19 pandemic on the prevalence of influenza A and respiratory syncytial viruses elucidated by wastewater-based epidemiology.

Since the COVID-19 pandemic, a decrease in the prevalence of Influenza A virus (IAV) and respiratory syncytial virus (RSV) has been suggested by clinical surveillance. However, there may be potential biases in obtaining an accurate overview of infectious diseases in a community. To elucidate the impact of the COVID-19 on the prevalence of IAV and RSV, we quantified IAV and RSV RNA in wastewater collected from three wastewater treatment plants (WWTPs) in Sapporo, Japan, between October 2018 and January 2023, using highly sensitive EPISENS™ method. From October 2018 to April 2020, the IAV M gene concentrations were positively correlated with the confirmed cases in the corresponding area (Spearman's r = 0.61). Subtype-specific HA genes of IAV were also detected, and their concentrations showed trends that were consistent with clinically reported cases. RSV A and B serotypes were also detected in wastewater, and their concentrations were positively correlated with the confirmed clinical cases (Spearman's r = 0.36-0.52). The detection ratios of IAV and RSV in wastewater decreased from 66.7 % (22/33) and 42.4 % (14/33) to 4.56 % (12/263) and 32.7 % (86/263), respectively in the city after the COVID-19 prevalence. The present study demonstrates the potential usefulness of wastewater-based epidemiology combined with the preservation of wastewater (wastewater banking) as a tool for better management of respiratory viral diseases.

mRNA vaccines: The future of prevention of viral infections?

Messenger RNA (mRNA) vaccines against COVID-19 are the first authorized biological preparations developed using this platform. During the pandemic, their administration has been proven to be a life-saving intervention. Here, we review the main advantages of using mRNA vaccines, identify further technological challenges to be met during the development of the mRNA platform, and provide an update on the clinical progress on leading mRNA vaccine candidates against different viruses that include influenza viruses, human immunodeficiency virus 1, respiratory syncytial virus, Nipah virus, Zika virus, human cytomegalovirus, and Epstein-Barr virus. The prospects and challenges of manufacturing mRNA vaccines in low-income countries are also discussed. The ongoing interest and research in mRNA technology are likely to overcome some existing challenges for this technology (e.g., related to storage conditions and immunogenicity of some components of lipid nanoparticles) and enhance the portfolio of vaccines against diseases for which classical formulations are already authorized. It may also open novel pathways of protection against infections and their consequences for which no safe and efficient immunization methods are currently available.

A multiplex-NGS approach to identifying respiratory RNA viruses during the COVID-19 pandemic.

A methodological approach based on reverse transcription (RT)-multiplex PCR followed by next-generation sequencing (NGS) was implemented to identify multiple respiratory RNA viruses simultaneously. A convenience sampling from respiratory surveillance and SARS-CoV-2 diagnosis in 2020 and 2021 in Montevideo, Uruguay, was analyzed. The results revealed the cocirculation of SARS-CoV-2 with human rhinovirus (hRV) A, B and C, human respiratory syncytial virus (hRSV) B, influenza A virus, and metapneumovirus B1. SARS-CoV-2 coinfections with hRV or hRSV B and influenza A virus coinfections with hRV C were identified in adults and/or children. This methodology combines the benefits of multiplex genomic amplification with the sensitivity and information provided by NGS. An advantage is that additional viral targets can be incorporated, making it a helpful tool to investigate the cocirculation and coinfections of respiratory viruses in pandemic and post-pandemic contexts.

Rapid differential diagnosis of SARS-CoV-2, influenza A/B and respiratory syncytial viruses: Validation of a novel RT-PCR assay.

BACKGROUND: Influenza and respiratory syncytial (RSV) viruses are expected to co-circulate with SARS-CoV-2 in the upcoming seasons and clinical differential diagnosis between them is difficult. Laboratory-based RT-PCR is a gold standard diagnostic method for influenza, RSV and SARS-CoV-2. The objective of this study was to estimate the diagnostic performance of a novel point-of-care RT-PCR assay STANDARD M10 Flu/RSV/SARS-CoV-2 (SD Biosensor) in a large number of clinical specimens with diversified (co)-infection patterns and viral loads. METHODS: This was a retrospective study, in which all samples were tested in both STANDARD M10 Flu/RSV/SARS-CoV-2 index and Allplex SARS-CoV-2/Respiratory Panel 1 (Seegene) reference kits. Samples with discordant results were further processed in a third resolver test (Resp-4-Plex, Abbott). RESULTS: A total of 1,019 naso-/oropharyngeal samples (50.3% positive for at least one virus) were processed in both STANDARD M10 Flu/RSV/SARS-CoV-2 and Allplex assays and the overall between-assay agreement was as high as 94.6%. Positive percent agreement of the STANDARD M10 Flu/RSV/SARS-CoV-2 was 100%, 96.6%, 97.3% and 99.4% for influenza A, B, RSV and SARS-CoV-2, respectively. The corresponding negative percent agreement was 99.7%. 100%, 100% and 98.4%, respectively. The expected positive and negative predictive values for all viruses were constantly above 96% in a reasonable range of disease prevalence. CONCLUSIONS: STANDARD M10 Flu/RSV/SARS-CoV-2 is a reliable RT-PCR assay able to detect influenza A, influenza B, RSV and SARS-CoV-2 in one hour or less, fostering a rapid differential diagnosis of common respiratory viruses.

Epidemiological Patterns of Seasonal Respiratory Viruses during the COVID-19 Pandemic in Madagascar, March 2020-May 2022.

Three epidemic waves of coronavirus disease-19 (COVID-19) occurred in Madagascar from March 2020 to May 2022, with a positivity rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of 21% to 33%. Our study aimed to identify the impact of COVID-19 on the epidemiology of seasonal respiratory viruses (RVs) in Madagascar. We used two different specimen sources (SpS). First, 2987 nasopharyngeal (NP) specimens were randomly selected from symptomatic patients between March 2020 and May 2022 who tested negative for SARS-CoV-2 and were tested for 14 RVs by multiplex real-time PCR. Second, 6297 NP specimens were collected between March 2020 and May 2022 from patients visiting our sentinel sites of the influenza sentinel network. The samples were tested for influenza, respiratory syncytial virus (RSV), and SARS-CoV-2. From SpS-1, 19% (569/2987) of samples tested positive for at least one RV. Rhinovirus (6.3%, 187/2987) was the most frequently detected virus during the first two waves, whereas influenza predominated during the third. From SpS-2, influenza, SARS-CoV-2, and RSV accounted for 5.4%, 24.5%, and 39.4% of the detected viruses, respectively. During the study period, we observed three different RV circulation profiles. Certain viruses circulated sporadically, with increased activity in between waves of SARS-CoV-2. Other viruses continued to circulate regardless of the COVID-19 situation. Certain viruses were severely disrupted by the spread of SARS-CoV-2. Our findings underline the importance and necessity of maintaining an integrated disease surveillance system for the surveillance and monitoring of RVs of public health interest.

Single-Center Experience in Detecting Influenza Virus, RSV and SARS-CoV-2 at the Emergency Department.

Reverse transcription polymerase chain reaction (RT-PCR) on respiratory tract swabs has become the gold standard for sensitive and specific detection of influenza virus, respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this retrospective analysis, we report on the successive implementation and routine use of multiplex RT-PCR testing for patients admitted to the Internal Medicine Emergency Department (ED) at a tertiary care center in Western Austria, one of the hotspots in the early coronavirus disease 2019 (COVID-19) pandemic in Europe. Our description focuses on the use of the Cepheid® Xpert® Xpress closed RT-PCR system in point-of-care testing (POCT). Our indications for RT-PCR testing changed during the observation period: From the cold season 2016/2017 until the cold season 2019/2020, we used RT-PCR to diagnose influenza or RSV infection in patients with fever and/or respiratory symptoms. Starting in March 2020, we used the RT-PCR for SARS-CoV-2 and a multiplex version for the combined detection of all these three respiratory viruses to also screen subjects who did not present with symptoms of infection but needed in-hospital medical treatment for other reasons. Expectedly, the switch to a more liberal RT-PCR test strategy resulted in a substantial increase in the number of tests. Nevertheless, we observed an immediate decline in influenza virus and RSV detections in early 2020 that coincided with public SARS-CoV-2 containment measures. In contrast, the extensive use of the combined RT-PCR test enabled us to monitor the re-emergence of influenza and RSV detections, including asymptomatic cases, at the end of 2022 when COVID-19 containment measures were no longer in place. Our analysis of PCR results for respiratory viruses from a real-life setting at an ED provides valuable information on the epidemiology of those infections over several years, their contribution to morbidity and need for hospital admission, the risk for nosocomial introduction of such infection into hospitals from asymptomatic carriers, and guidance as to how general precautions and prophylactic strategies affect the dynamics of those infections.

Development of mRNA vaccines against respiratory syncytial virus (RSV).

Respiratory syncytial virus (RSV) is a single-stranded negative-sense RNA virus that is the primary etiologic pathogen of bronchitis and pneumonia in infants and the elderly. Currently, no preventative vaccine has been approved for RSV infection. However, advances in the characterization, and structural resolution, of the RSV surface fusion glycoprotein have revolutionized RSV vaccine development by providing a new target for preventive interventions. In general, six different approaches have been adopted in the development of preventative RSV therapeutics, namely, particle-based vaccines, vector-based vaccines, live-attenuated or chimeric vaccines, subunit vaccines, mRNA vaccines, and monoclonal antibodies. Among these preventive interventions, MVA-BN-RSV, RSVpreF3, RSVpreF, Ad26. RSV.preF, nirsevimab, clesrovimab and mRNA-1345 is being tested in phase 3 clinical trials, and displays the most promising in infant or elderly populations. Accompanied by the huge success of mRNA vaccines in COVID-19, mRNA vaccines have been rapidly developed, with many having entered clinical studies, in which they have demonstrated encouraging results and acceptable safety profiles. In fact, Moderna has received FDA approval, granting fast-track designation for an investigational single-dose mRNA-1345 vaccine against RSV in adults over 60 years of age. Hence, mRNA vaccines may represent a new, more successful, chapter in the continued battle to develop effective preventative measures against RSV. This review discusses the structure, life cycle, and brief history of RSV, while also presenting the current advancements in RSV preventatives, with a focus on the latest progress in RSV mRNA vaccine development. Finally, future prospects for this field are presented.

Changes in endemic patterns of respiratory syncytial virus infection in pediatric patients under the pressure of nonpharmaceutical interventions for COVID-19 in Beijing, China.

A series of nonpharmaceutical interventions (NPIs) was launched in Beijing, China, on January 24, 2020, to control coronavirus disease 2019. To reveal the roles of NPIs on the respiratory syncytial virus (RSV), respiratory specimens collected from children with acute respiratory tract infection between July 2017 and Dec 2021 in Beijing were screened by capillary electrophoresis-based multiplex PCR (CEMP) assay. Specimens positive for RSV were subjected to a polymerase chain reaction (PCR) and genotyped by G gene sequencing and phylogenetic analysis using iqtree v1.6.12. The parallel and fixed (paraFix) mutations were analyzed with the R package sitePath. Clinical data were compared using SPSS 22.0 software. Before NPIs launched, each RSV endemic season started from October/November to February/March of the next year in Beijing. After that, the RSV positive rate abruptly dropped from 31.93% in January to 4.39% in February 2020; then, a dormant state with RSV positive rates ≤1% from March to September, a nearly dormant state in October (2.85%) and November (2.98%) and a delayed endemic season in 2020, and abnormal RSV positive rates remaining at approximately 10% in summer until September 2021 were detected. Finally, an endemic RSV season returned in October 2021. There was a game between Subtypes A and B, and RSV-A replaced RSV-B in July 2021 to become the dominant subtype. Six RSV-A and eight RSV-B paraFix mutations were identified on G. The percentage of severe pneumonia patients decreased to 40.51% after NPIs launched. NPIs launched in Beijing seriously interfered with the endemic season of RSV.