Seasonal Viruses Research Articles

Respiratory virus infections after allogeneic stem cell transplantation: Current understanding, knowledge gaps, and recent advances.

Before the COVID-19 pandemic, common community-acquired seasonal respiratory viruses (CARVs) were a significant threat to the health and well-being of allogeneic hematopoietic cell transplant (allo-HCT) recipients, often resulting in severe illness and even death. The pandemic has further highlighted the significant risk that immunosuppressed patients, including allo-HCT recipients, face when infected with SARS-CoV-2. As preventive transmission measures are relaxed and CARVs circulate again among the community, including in allo-HSCT recipients, it is crucial to understand the current state of knowledge, gaps, and recent advances regarding CARV infection in allo-HCT recipients. Urgent research is needed to identify seasonal respiratory viruses as potential drivers for future pandemics.

Trend in respiratory viruses' activity in the COVID-19 area.

SARS-CoV-2 has impacted the detection of seasonal respiratory viruses. We retrospectively assessed the trend in the detection of 10 viruses in the COVID-19 area in 2 hospitals located in the Paris area. All patients positive for a respiratory virus in two hospitals from September 2016 to August 2021 were retrospectively included. The rate of RT-PCR positive for each virus was calculated for the 2020-2021 season and the 2019-2020 season in comparison to a baseline of 3 seasons, i.e. 2016-2017, 2017-2018, and 2018-2019. Overall, 7,835 patients were tested positive from September 2016 to August 2021. The detection of respiratory virus dramatically falls on week-11 of 2020, as the number of RT-PCR performed. Then, 3 trends were identified: a) almost a disappearance for influenza; b) a 10-weeks delay in the seasonal outbreak for RSV; c) a persistence of circulation with variable activity for other viruses. In comparison to a baseline of three seasons (2016-2019), the rate of positive patients was lower during the 2020-2021 season for coronavirus (4.51% vs. 1.26%, P <0.0001), adenovirus (1.93% vs. 1.34%, P =0.14), bocavirus (0.58% vs. 0.11%, P =0.08), and enterovirus (0.28% vs. 0.0%, P =0.12). In contrast, the rate of hMPV-positive (1.92% vs. 2.83%, P =0.03) and hPIV-positive (2.17% vs. 2.99%, P =0.06) patients increased. The fall in the number of respiratory viruses detected might be related to the lower number of tests performed and the implementation of non pharmaceutical intervention (NPI). Then, all viruses except influenza are detected, probably as a consequence of high adherence to influenza vaccines. Despite, a lower number of tests being performed, the rate of hMPV-positive and hPIV-positive patients increased suggesting an active circulation of these viruses. Altogether, these findings suggest a persistent circulation of common respiratory viruses all over the COVID-19 era.

Use of Biolayer Interferometry to Identify Dominant Binding Epitopes of Influenza Hemagglutinin Protein of A(H1N1)pdm09 in the Antibody Response to 2010-2011 Influenza Seasonal Vaccine.

The globular head domain of influenza virus surface protein hemagglutinin (HA1) is the major target of neutralizing antibodies elicited by vaccines. As little as one amino acid substitution in the HA1 can result in an antigenic drift of influenza viruses, indicating the dominance of some epitopes in the binding of HA to polyclonal serum antibodies. Therefore, identifying dominant binding epitopes of HA is critical for selecting seasonal influenza vaccine viruses. In this study, we have developed a biolayer interferometry (BLI)-based assay to determine dominant binding epitopes of the HA1 in antibody response to influenza vaccines using a panel of recombinant HA1 proteins of A(H1N1)pdm09 virus with each carrying a single amino acid substitution. Sera from individuals vaccinated with the 2010-2011 influenza trivalent vaccines were analyzed for their binding to the HA1 panel and hemagglutination inhibition (HI) activity against influenza viruses with cognate mutations. Results revealed an over 50% reduction in the BLI binding of several mutated HA1 compared to the wild type and a strong correlation between dominant residues identified by the BLI and HI assays. Our study demonstrates a method to systemically analyze antibody immunodominance in the humoral response to influenza vaccines.

Human anti-N1 monoclonal antibodies elicited by pandemic H1N1 virus infection broadly inhibit HxN1 viruses in vitro and in vivo

Neuraminidase (NA) is one of the two influenza virus surface glycoproteins, and antibodies that target it are an independent correlate of protection. However, our current understanding of NA antigenicity is incomplete. Here, we describe human monoclonal antibodies (mAbs) from a patient with a pandemic H1N1 virus infection in 2009. Two mAbs exhibited broad reactivity and inhibited NA enzyme activity of seasonal H1N1 viruses circulating before and after 2009, as well as viruses with avian or swine N1s. The mAbs provided robust protection from lethal challenge with human H1N1 and avian H5N1 viruses in mice, and both target an epitope on the lateral face of NA. In summary, we identified two broadly protective NA antibodies that share a novel epitope, inhibited NA activity, and provide protection against virus challenge in mice. Our work reaffirms that NA should be included as a target in future broadly protective or universal influenza virus vaccines.

H3N2 influenza A virus gradually adapts to human-type receptor binding and entry specificity after the start of the 1968 pandemic

To become established upon zoonotic transfer, influenza A viruses (IAV) need to switch binding from "avian-type" α2-3-linked sialic acid receptors (2-3Sia) to "human-type" Siaα2-6-linked sialic acid receptors (2-6Sia). For the 1968 H3N2 pandemic virus, this was accomplished by two canonical amino acid substitutions in its hemagglutinin (HA) although a full specificity shift had not occurred. The receptor repertoire on epithelial cells is highly diverse and simultaneous interaction of a virus particle with a range of low- to very low-affinity receptors results in tight heteromultivalent binding. How this range of affinities determines binding selectivity and virus motility remains largely unknown as the analysis of low-affinity monovalent HA-receptor interactions is technically challenging. Here, a biolayer interferometry assay enabled a comprehensive analysis of receptor-binding kinetics evolution upon host-switching. Virus-binding kinetics of H3N2 virus isolates slowly evolved from 1968 to 1979 from mixed 2-3/2-6Sia specificity to high 2-6Sia specificity, surprisingly followed by a decline in selectivity after 1992. By using genetically tuned HEK293 cells, presenting either a simplified 2-3Sia- or 2-6Sia-specific receptor repertoire, receptor-specific binding was shown to correlate strongly with receptor-specific entry. In conclusion, the slow and continuous evolution of entry and receptor-binding specificity of seasonal H3N2 viruses contrasts with the paradigm that human IAVs need to rapidly acquire and maintain a high specificity for 2-6Sia. Analysis of the kinetic parameters of receptor binding provides a basis for understanding virus-binding specificity, motility, and HA/neuraminidase balance at the molecular level.

Safety of Re-dosing Nirsevimab Prior to RSV Season 2 in Children With Heart or Lung Disease.

In children with congenital heart disease and/or chronic lung disease entering their second respiratory syncytial virus (RSV) season, 200 mg nirsevimab had a similar safety profile to that of palivizumab and resulted in nirsevimab serum exposures associated with efficacy in healthy infants, supporting efficacy in this population at risk of severe RSV disease.

Road salt pollution alters sex ratios in emerging mosquito populations

De-icing road salt is a persistent emerging pollutant in temperate freshwater systems, where winter salting is necessary for road and pedestrian safety. Experts argue that road salts may increase salt-tolerant mosquito populations and, potentially, disease transmission in urban areas. Only adult females consume bloodmeals and may carry zoonotic diseases. While there are some species with naturally occurring male-biased sex ratios, it is unclear whether road salt differentially affects male and female mosquitoes to alter sex ratios. We hypothesized that road salts would masculinize emergence sex ratios and decrease female success because females may face higher exposure to stressors during their lengthy juvenile development compared to males. We measured mosquito emergence sex ratios of control (0 g/L added salt) and salt (4.5 g/L added salt) mesocosms in southern Ontario, Canada across the West Nile Virus season (May to October). We found female-biased sex ratios (i.e., <50% male frequency) in both 0 and 4.5 g/L. While mosquito abundance was significantly higher in 4.5 g/L compared to 0 g/L, road salt significantly increased the proportion of emerging males from 32.8% to 40.8% (Negative Binomial Model; Estimate ± SE = 0.283 ± 0.108; P = 0.009); mosquitoes shift their sex ratios from female-biased towards parity (50:50) in response to salt. Our study illustrates the need to evaluate sex-specific abundance in pollution-related mosquito population studies. By showing a shift toward more male mosquitoes emerging in high salinity compared to control treatments, our results suggest that road salts may have the potential to decrease female mosquito success and indirectly reduce disease transmission in cities.

Seasonal Respiratory Virus Circulation in a Tertiary Care Hospital in Greece

Background: The COVID-19 pandemic caused by the novel SARS-CoV-2 virus affected health care systems and public health worldwide dramatically. Several measures were applied in order to prevent or stop the rapid transmission of the virus and the subsequent disease, such as lockdowns, physical distancing, strictly hygiene, along with travel restrictions. Global population after vaccination programs against COVID-19 were carried out, is facing a “tripledemic” situation threat, with the co-existance of SARS-CoV-2, influenza and RSV. The aim of the present study was to evaluate the co-existence of SARS-CoV-2, influenza and RSV, as well as the correlation with gender, age, Cts and vaccination doses. Methods: A total of 302 patients were included in the study. All patients were admitted to the emergency department of General Hospital Nikea, Piraeus with common upper respiratory tract symptoms and were suspected for COVID-19 disease, between March to July 2022. Patients’ age, gender, vaccination doses, and results from RT-PCR detection for SARS-CoV-2, RSV and Influenza viruses were recorded. Results: 139 were male and 163 female, aged between 18-94 years. Out of the patients included in the study, 206 were vaccinated and 96 were not vaccinated. Among vaccinated patients 97 were male and 109 were female. A percentage of 3.3% had received one vaccination dose, 16.9% two and 47.7% three. Moreover, 88 patients presented infection symptoms; 81 patients had a positive rapid test result. We detected 15 cases of co-infection of SaRS-CoV-2 and RSV and only one case, of co-infection of SaRS-CoV-2 with influenza virus. Conclusions: The majority of patients admitted to the emergency department of GHNP with common upper respiratory tract clinical manifestations were female. A significantly lower rate of co-infection with SARS-CoV-2 and RSV was detected in patients having received 2 vaccination doses, compared to patients having received 3 out of 3 vaccination doses or up to 1 vaccination dose. Ct values for SARS-CoV-2 and RSV pathogens were between 10-17. Co-infection with SARS-CoV-2 and Influenza was detected in only 1 patient.

The 2022 West Nile Virus Season in Greece; A Quite Intense Season.

Since 2010, the West Nile virus (WNV) has been established in Greece. We describe the epidemiology of diagnosed human WNV infections in Greece with a focus on the 2022 season. During the transmission period, clinicians were sending samples from suspected cases for testing. Active laboratory-based surveillance was performed with immediate notification of diagnosed cases. We collected clinical information and interviewed patients on a timely basis to identify their place of exposure. Besides serological and molecular diagnostic methods, next-generation sequencing was also performed. In 2022, 286 cases of WNV infection were diagnosed, including 278 symptomatic cases and 184 (64%) cases with neuroinvasive disease (WNND); 33 patients died. This was the third most intense season concerning the number of WNND cases, following 2018 and 2010. Most (96%) cases were recorded in two regions, in northern and central Greece. The virus strain was a variant of previous years, clustering into the Central European subclade of WNV lineage 2. The 2022 WNV season was quite intense in Greece. The prompt diagnosis and investigation of cases are considered pivotal for the timely response, while the availability of whole genome sequences enables studies on the molecular epidemiology of the disease.

Severe acute respiratory syndrome in children treated at a pediatric referral hospital in Brazil during the COVID-19 pandemic

Background - Although we have accumulated knowledge along with the pandemic, there are still gaps, including the impact of seasonal conditions of SARS-CoV-2 and other respiratory viruses. Methods - A retrospective cohort study that aimed to describe the etiological diagnosis and compare the clinical presentation and outcomes of children with Severe Acute Respiratory Syndrome (SARS). Results – 1,027 children diagnosed with SARS were evaluated. In 926 (90.2%) children who collected RT-PCR Covid, 2.3% had a positive result. A total of 365 (35.4%) of the children underwent collection for Viral Panel exam, with identification of the etiology in 28%. There was a statistically significant difference in the age of patients infected with RSV and other viruses. The length of hospital stay was statistically different (p:0.006) when comparing groups of rhinovirus with COVID or RSV. Conclusion - This study is a pioneer in conducting large-scale testing for respiratory viruses in pediatric patients during the pandemic and contributes to the knowledge about the etiology of SARS in childhood, and this disease's relationship with the seasonality of respiratory viruses.

Leaving Without Being Seen From the Pediatric Emergency Department: A New Baseline

BackgroundLeft without being seen (LWBS) rates are an important quality metric for pediatric emergency departments (EDs), with high-acuity LWBS children representing a patient safety risk. Since July 2021, our ED experienced a surge in LWBS after the most stringent COVID-19 quarantine restrictions ended. ObjectiveWe assessed changes in LWBS rates and examined associations of system factors and patient characteristics with LWBS. MethodsWe performed a retrospective study in a large, urban pediatric ED for all arriving patients, comparing the following three time-periods: before COVID-19 (PRE, January 2018–February 2020), during early COVID-19 (COVID, March 2020–June 2021), and after the emergence of COVID-19 variants and re-emergence of seasonal viruses (POST, July 2021–December 2021). We compared descriptive statistics of daily LWBS rates, patient demographic characteristics, and system characteristics. Negative binomial (system factors) and logistic regression (patient characteristics) models were developed to evaluate the associations between system factors and LWBS, and patient characteristics and LWBS, respectively. ResultsMean daily LWBS rates changed from 1.8% PRE to 1.4% COVID to 10.7% during POST. Rates increased across every patient demographic and triage level during POST, despite a decrease in daily ED volume compared with PRE. LWBS rates were significantly associated with patients with an Emergency Severity Index score of 2, mean ED census, and staff productivity within multiple periods. Patient characteristics associated with LWBS included lower assigned triage levels and arrival between 8 pm and 4 am. ConclusionsLWBS rates have shown a large and sustained increase since July 2021, even for high-acuity patients. We identified system factors that may provide opportunities to reduce LWBS. Further work should develop strategies to prevent LWBS in at-risk patients.

Kawasaki Disease and Respiratory Viruses: Ecological Spatiotemporal Analysis.

Kawasaki disease is an uncommon vasculitis affecting young children. Its etiology is not completely understood, although infections have been frequently postulated as the triggers. Respiratory viruses, specifically, have often been implicated as causative agents for Kawasaki disease presentations. We aimed to conduct an ecological spatiotemporal analysis to determine whether Kawasaki disease incidence was related to community respiratory virus circulation in a shared region and population, and to describe viral associations before and during the COVID-19 pandemic. We obtained independent statewide data sets of hospital admissions of Kawasaki disease and respiratory multiplex polymerase chain reaction tests performed at two large hospital networks in Victoria, Australia, from July 2011 to November 2021. We studied spatiotemporal relationships by negative binomial regression analysis of the monthly incidence of Kawasaki disease and the rate of positive respiratory polymerase chain reaction tests in different regions of Victoria. Peak viral seasons (95th percentile incidence) were compared to median viral circulation (50th percentile incidence) to calculate peak season increased rate ratios. While no seasonal trend in Kawasaki disease incidence was identified throughout the study period, we found a 1.52 (99% CI 1.27-1.82) and a 1.43 (99% CI 1.17-1.73) increased rate ratio of Kawasaki disease presentations in association with human metapneumovirus and respiratory syncytial virus circulation, respectively, before the COVID-19 pandemic. No respiratory viral associations with Kawasaki disease were observed during the COVID-19 pandemic. Our large ecological analysis demonstrates novel spatiotemporal relationships between human metapneumovirus and respiratory syncytial virus circulation with Kawasaki disease. The disappearance of these associations in the COVID-19 pandemic may reflect the reduced circulation of non-SARS-CoV-2 viruses during this period, supporting the prepandemic associations identified in this study. The roles of human metapneumovirus and respiratory syncytial virus in Kawasaki disease etiology warrant further investigation.

Changing pattern of respiratory virus detections among school‐aged children in a small community – Dane County, Wisconsin, September to December 2022

AbstractWidespread school closures and other non‐pharmaceutical interventions (NPIs), used to limit the spread of SARS‐CoV‐2, significantly disrupted transmission patterns of seasonal respiratory viruses. As NPIs were relaxed, populations were vulnerable to resurgence. This study within a small community assessed acute respiratory illness among kindergarten through grade 12 students as they returned to public schools from September through December 2022 without masking and distancing requirements. The 277 specimens collected demonstrated a shift from rhinovirus to influenza. With continued circulation of SARS‐CoV‐2 and return of seasonal respiratory viruses, understanding evolving transmission patterns will play an important role in reducing disease burden.

A pan-influenza antibody inhibiting neuraminidase via receptor mimicry

Rapidly evolving influenza A viruses (IAVs) and influenza B viruses (IBVs) are major causes of recurrent lower respiratory tract infections. Current influenza vaccines elicit antibodies predominantly to the highly variable head region of haemagglutinin and their effectiveness is limited by viral drift1 and suboptimal immune responses2. Here we describe a neuraminidase-targeting monoclonal antibody, FNI9, that potently inhibits the enzymatic activity of all group 1 and group 2 IAVs, as well as Victoria/2/87-like, Yamagata/16/88-like and ancestral IBVs. FNI9 broadly neutralizes seasonal IAVs and IBVs, including the immune-evading H3N2 strains bearing an N-glycan at position 245, and shows synergistic activity when combined with anti-haemagglutinin stem-directed antibodies. Structural analysis reveals that D107 in the FNI9 heavy chain complementarity-determinant region 3 mimics the interaction of the sialic acid carboxyl group with the three highly conserved arginine residues (R118, R292 and R371) of the neuraminidase catalytic site. FNI9 demonstrates potent prophylactic activity against lethal IAV and IBV infections in mice. The unprecedented breadth and potency of the FNI9 monoclonal antibody supports its development for the prevention of influenza illness by seasonal and pandemic viruses.

Severe Neonatal Interstitial Lung Disease Caused by a Rare Surfactant Protein C Mutation.

Childhood interstitial lung disease (chILD) is a collective term for a group of rare lung disorders of heterogeneous origin. Surfactant dysfunction disorders are a cause of chILD with onset during the neonatal period and infancy. Clinical signs of tachypnea and hypoxemia are nonspecific and usually caused by common conditions like lower respiratory tract infections. We report on a full-term male newborn who was readmitted to the hospital at 7 days of age with marked tachypnea and poor feeding during the respiratory syncytial virus season. After exclusion of infection and other, more common congenital disorders, chILD was diagnosed using chest computed tomography and genetic analysis. A likely pathogenic heterozygous variant of SFTPC (c.163C>T, L55F) was detected by whole exome sequencing. The patient received supplemental oxygen and noninvasive respiratory support and was treated with intravenous methylprednisolone pulses and hydroxychloroquine. Despite the treatment, his respiratory situation deteriorated continuously, leading to several hospitalizations and continuous escalation of noninvasive ventilatory support. At 6 months of age, the patient was listed for lung transplant and transplanted successfully aged 7 months.

Always a bridesmaid, never a bride: Committing to flu neuraminidase as a vaccine target

Influenza A viruses pose an ongoing threat due to their role in seasonal epidemics and the potential for the emergence of novel viruses from the animal reservoir. 1 Kerstetter L.J. Buckley S. Bliss C.M. Coughlan L. Adenoviral vectors as vaccines for emerging avian influenza viruses. Front. Immunol. 2020; 11607333https://doi.org/10.3389/fimmu.2020.607333 Crossref PubMed Scopus (12) Google Scholar Extensive efforts are being made to develop vaccines that elicit protection against multiple influenza virus antigens, as well as universal vaccines that confer broad protection against antigenically distinct seasonal and/or pandemic viruses. In order to achieve long-lived and cross-protective immunity, it is considered that combining distinct vaccine platforms in heterologous prime:boost regimens may be required. 2 Coughlan L. Palese P. Overcoming barriers in the path to a universal influenza virus vaccine. Cell Host Microbe. 2018; 24: 18-24https://doi.org/10.1016/j.chom.2018.06.016 Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar

Respiratory Syncytial Virus, Influenza, and Coronavirus Disease 2019 Hospitalizations in Children in Colorado During the 2021-2022 Respiratory Virus Season

To compare demographic characteristics, clinical features, and outcomes of children hospitalized with respiratory syncytial virus (RSV), influenza, or severe acute respiratory syndrome coronavirus 2 during their cocirculation 2021-2022 respiratory virus season. We conducted a retrospective cohort study using Colorado's hospital respiratory surveillance data comparing coronavirus disease 2019 (COVID-19)-, influenza-, and RSV-hospitalized cases < 18years of age admitted and undergoing standardized molecular testing between October 1, 2021, and April 30, 2022. Multivariable log-binomial regression modeling evaluated associations between pathogen type and diagnosis, intensive care unit admission, hospital length of stay, and highest level of respiratory support received. Among 847 hospitalized cases, 490 (57.9%) were RSV associated, 306 (36.1%) were COVID-19 associated, and 51 (6%) were influenza associated. Most RSV cases were <4years of age (92.9%), whereas influenza hospitalizations were observed in older children. RSV cases were more likely to require oxygen support higher than nasal cannula compared with COVID-19 and influenza cases (P<.0001), although COVID-19 cases were more likely to require invasive mechanical ventilation than influenza and RSV cases (P < .0001). Using multivariable log-binomial regression analyses, compared with children with COVID-19, the risk of intensive care unit admission was highest among children with influenza (relative risk, 1.97; 95% CI, 1.22-3.19), whereas the risk of pneumonia, bronchiolitis, longer hospital length of stay, and need for oxygen were more likely among children with RSV. In a season with respiratory pathogen cocirculation, children were hospitalized most commonly for RSV, were younger, and required higher oxygen support and non-invasive ventilation compared with children with influenza and COVID-19.

Improvement in Palivizumab Administration Prior to Discharge for Hospitalized Infants with Hemodynamically Significant Congenital Heart Disease: A Quality Improvement Initiative.

In this quality improvement initiative, we aimed to increase provider adherence with palivizumab administration guidelines for hospitalized infants with hemodynamically significant congenital heart disease. We included 470 infants over four respiratory syncytial virus (RSV) seasons from 11/2017 to 03/2021 (baseline season: 11/2017-03/2018). Interventions included the following: education, including palivizumab in the sign-out template, identifying a pharmacy expert, and a text alert (seasons 1 and 2: 11/2018-03/2020) that was replaced by an electronic health record (EHR) best practice alert (BPA) in season 3 (11/2020-03/2021). The text alert and BPA prompted providers to add "Need for RSV immunoprophylaxis" to the EHR problem list. The outcome metric was the percentage of eligible patients administered palivizumab prior to discharge. The process metric was the percentage of eligible patients with "Need for RSV immunoprophylaxis" on the EHR problem list. The balancing metric was the percentage of palivizumab doses administered to ineligible patients. A statistical process control P-chart was used to analyze the outcome metric. The mean percentage of eligible patients who received palivizumab prior to hospital discharge increased significantly from 70.1% (82/117) to 90.0% (86/96) in season 1 and to 97.9% (140/143) in season 3. Palivizumab guideline adherence was as high or higher for those with "Need for RSV immunoprophylaxis" on the problem list than for those without it in most time periods. The percentage of inappropriate palivizumab doses decreased from 5.7% (n = 5) at baseline to 4.4% (n = 4) in season 1 and 0.0% (n = 0) in season 3. Through this initiative, we improved adherence with palivizumab administration guidelines for eligible infants prior to hospital discharge.

Healthcare-associated Respiratory Syncytial Virus in Children's Hospitals.

Outbreaks of healthcare-associated respiratory syncytial virus (HA-RSV) infections in children are well described, but less is known about sporadic HA-RSV infections. We assessed the epidemiology and clinical outcomes associated with sporadic HA-RSV infections. We retrospectively identified hospitalized children <18 years old with HA-RSV infections in six children's hospitals in the United States during the respiratory viral seasons October-April in 2016-2017, 2017-2018, and 2018-2019 and prospectively from October 2020 through November 2021. We evaluated outcomes temporally associated with HA-RSV infections including escalation of respiratory support, transfer to the pediatric intensive care unit (PICU), and in-hospital mortality. We assessed demographic characteristics and comorbid conditions associated with escalation of respiratory support. We identified 122 children (median age 16.0 months [IQR 6, 60 months]) with HA-RSV. The median onset of HA-RSV infections was hospital day 14 (IQR 7, 34 days). Overall, 78 (63.9%) children had two or more comorbid conditions; cardiovascular, gastrointestinal, neurologic/neuromuscular, respiratory, and premature/ neonatal comorbidities were most common. Fifty-five (45.1%) children required escalation of respiratory support and 18 (14.8%) were transferred to the PICU. Five (4.1%) died during hospitalization. In the multivariable analysis, respiratory comorbidities (aOR: 3.36 [CI95 1.41, 8.01]) were associated with increased odds of escalation of respiratory support. HA-RSV infections cause preventable morbidity and increase healthcare resource utilization. Further study of effective mitigation strategies for HA-respiratory viral infections should be prioritized; this priority is further supported by the impact of the COVID-19 pandemic on seasonal viral infections.

Is H3N2 Influenza flare-up and troubling like COVID?

COVID and H3N2 influenza instances are on ascent in India. Both COVID-19 and H3N2 are the infectious viruses. They promulgate through droplets. COVID is transmitted by SARs –Cov2 virus and H3N2 acquired by Influenza A sub type. Contrast to H3N2, COVID 19 cause more serious and symptoms can take longer than flu symptoms. The COVID-19 not only poses a serious threat to the health of people worldwide but also affects the global economy. H3N2 is a variety of influenza virus that has been present among humans since the late 1960s. It is often called the "Hong Kong flu" due to its roots in Asia. Viruses that normally disperse in pigs are “swine influenza viruses". H3N2 is a subtype of the viral genus Influenza Virus A, which is a major cause of current respiratory illness. The H3N2 virus is a non-human influenza virus that normally circulates in pigs and has infected humans with symptoms similar to seasonal flu viruses. Influenza outbreaks have caused widespread illness to humans many times throughout history. In 1968 an avian reasserting virus of the H3N2 subtype was introduced into the human population that caused a global pandemic associated with more than one million deaths world-wide. About half of all inpatient severe acute respiratory infections.H3N2 hospitalized patients suffer from fever, cough, breathlessness and wheezing. Few patients needed oxygen and ICU care. Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern.