Administration of the GSK Respiratory Syncytial Virus Vaccine to Pregnant Persons in Error.

The GSK and Pfizer respiratory syncytial virus (RSV) vaccines are both indicated for adults aged 60 years and older, but only the Pfizer product is approved for use in pregnancy to prevent RSV-associated lower respiratory tract disease in infants aged younger than 6 months. To assess for vaccine administration errors (ie, administration of the GSK RSV vaccine to pregnant persons) VAERS (Vaccine Adverse Event Reporting System), a U.S. passive reporting system, was searched for the time period from August 2023 to January 2024. A total of 113 reports of these administration errors were identified. Most reports (103, 91.2%) did not describe an adverse event. These administration errors are preventable with proper education and training and other preventive measures.

The third pandemic: The respiratory syncytial virus landscape and specific considerations for the allergist/immunologist.

Background: Since its initial identification in 1956, respiratory syncytial virus (RSV) has been the second most common cause of mortality in infants <6 months of age and a major cause of morbidity and mortality associated with lower respiratory tract infection (LRTI) in older adults (ages >60 years) worldwide. Of particular interest to the allergist/immunologist is a growing body of evidence that suggests an association between LRTI caused by RSV in infants with later-life development of asthma, wheezing, or impaired lung function in adults. Efforts to develop a RSV vaccine have been thwarted for >70 years by the occurrence of enhanced respiratory disease (ERD), an adverse RSV vaccine reaction, in the 1960s, in which more-severe illness occurred on natural infection after vaccination of infants who were RSV naive and with a formalin-inactivated RSV vaccine. Recent advances in knowledge of the structural biology of the RSV surface fusion glycoprotein, however, have revolutionized RSV vaccine development for preventive interventions and have offered, at last, the hope of an effective and safe vaccine for the prevention of RSV disease. Objective: The purpose of this report was to examine the current evidence that supports the epidemiology, disease manifestations, molecular biology, treatments, and new vaccine development of RSV vaccines. Results: The host-immune response to RSV infection is carried out by two distinct but overlapping universes of mucosal and systemic immune systems in which a balanced set of B- and T-cell responses are involved in protective immunity that includes the mucosal immune system in which immunoglobulin A (IgA) prevails and the systemic immune system in which IgG neutralizing antibody predominates. The key to developing an effective vaccine is now thought to be linked to the availability of a stabilized prefusion F protein in the immunizing vaccine, which can perform a dual function of a balanced mucosal and/or systemic immune response as well as an effective antibody specifically directed to critical epitopes on the requisite prefusion F protein. Conclusion: The unfortunate manifestation of RSV ERD that occurred in the 1960s has led to a better understanding of the structural biology of the RSV surface fusion glycoprotein and has provided a basis for the development of more effective and safer RSV vaccines and monoclonal antibody preparations for immunoprophylaxis of the dread effects of RSV disease. There are now a large number of clinical trials in progress that are evaluating these products, which include recombinant vector, subunit, particle-based, live-attenuated, chimeric, and nucleic acid vaccines; and monoclonal antibodies. This article gives an overview of the many aspects of RSV disease and development of virus (RSV) vaccines of particular interest to the allergist/immunologist.

New strategies for the prevention of respiratory syncytial virus (RSV).

Respiratory Syncytial Virus (RSV) is the main cause of lower respiratory tract infections (LRTIs) in newborns in the first two years of life. RSV disease has a traditional seasonal trend, with an onset and offset, duration and peak. Prematurity, male gender, bronchopulmonary dysplasia (BPD), critical congenital cardiovascular disorders (CCHD), neuromuscular diseases, congenital and inherited airways anatomical anomalies are the main risk factors for increased severity of this infection. RSV infection is associated with negative long-term respiratory outcomes, with excess of morbidity, resulting in reduced quality of life of the infected children and representing a burden for the healthcare costs and resources. Despite all the efforts, prevention remains, to date, the most effective strategy to reduce RSV-related morbidity. Among the current prevention strategies, strict hygiene, breastfeeding and passive immunization with the monoclonal antibody Palivizumab are the cornerstone. In the next future, it is likely that new possibilities of prevention will add, including use of more potent and longer-acting monoclonal antibodies, implementation of maternal vaccination in pregnancy, and active immunization in children. The purpose of this review is to provide an overview of the main current and future prevention strategies against RSV.

Respiratory Viruses: Influenza, RSV, and Adenovirus in Kidney Transplantation.

Although advances in immunosuppression and antimicrobial prophylaxis have led to improved patient and graft survival, respiratory viruses continue to be a common cause of morbidity and mortality in immunocompromised populations. We describe the clinical manifestations, diagnosis and treatment options for influenza, respiratory syncytial virus and adenovirus infection in the kidney transplant population.

Haze is a risk factor contributing to the rapid spread of respiratory syncytial virus in children.

This study investigated whether respiratory syncytial virus (RSV) infection in children was associated with ambient temperature and air pollutants in Hangzhou, China. A distributed lag non-linear model (DLNM) was used to estimate the effects of daily meteorological data and air pollutants on the incidence of RSV infection among children. A total of 3650 childhood RSV infection cases were included in the study. The highest air pollutant concentrations were in January to May and October to December during the year. The yearly RSV-positive rate was 10.0 % among children with an average age of 4.3 months. The highest RSV-positive rate occurred among patients 0 to 3 months old. Children under 6.5 months old accounted for 80 % of the total patients infected by RSV. A negative correlation was found between ambient temperature and RSV infection, and it was strongest with minimum ambient temperature (r = -0.804, P < 0.001). There was a positive correlation between the infection rate and the particulate matter (PM) 2.5 (r = 0.446, P < 0.001), PM10 (r = 0.397, P < 0.001), SO2 (r = 0.389, P < 0.001), NO2 (r = 0.365, P < 0.001) and CO (r = 0.532, P < 0.001). The current study suggested that temperature was an important factor associated with RSV infection among children in Hangzhou. Air pollutants significantly increased the risk of RSV infection with dosage, lag and cumulative effects.

Dual effects of respiratory syncytial virus infections on airway inflammation by regulation of Th17/Treg responses in ovalbumin-challenged mice.

We investigated the effects of respiratory syncytial virus (RSV) infections on ovalbumin (OVA)-challenged mice via regulation of Th17/Treg cell responses. BALB/c mice were challenged with OVA, followed by RSV infections twice. In OVA-challenged mice, the secretion of Th2/Th17-type cytokines, airway hyperresponsiveness and inflammation were significantly inhibited by initial RSV infection. Moreover, the in vivo findings demonstrated that initial RSV infection reversed the imbalance of Th17/Treg responses. In contrast, RSV re-infection strengthened Th2/Th17-type cytokine secretion, airway hyperresponsiveness, and inflammation, especially for lymphocyte infiltration in OVA-challenged mice. Meanwhile, RSV re-infection enhanced the imbalanced Th17/Treg responses. Upon all results reveal that RSV-induced respiratory infections may lead to dual effects pertaining to allergic airway inflammation by regulation of Th17/Treg responses.

Respiratory syncytial virus infection in infants and correlation with meteorological factors and air pollutants.

BACKGROUND: Respiratory Syncytial Virus (RSV) is the most important cause of severe respiratory infections in infants with seasonal epidemics. Environmental factors (temperature, humidity, air pollution) could influence RSV epidemics through their effects on virus activity and diffusion. METHODS: We conducted a retrospective study on a paediatric population who referred to our Paediatric Emergency Unit in order to analyze the correlation between weekly incidence of RSV positive cases during winter season in Bologna and meteorological factors and air pollutants concentration. RESULTS: We observed a significant correlation between the incidence of RSV infections and the mean minimum temperature registered during the same week and the previous weeks.The weekly number of RSV positive cases was also correlated to the mean PM10 concentration of the week before. CONCLUSIONS: RSV epidemic trend in Bologna (Italy) is related to the mean minimum temperature, and the mean PM10 concentration.

Infant exposure to fine particulate matter and traffic and risk of hospitalization for RSV bronchiolitis in a region with lower ambient air pollution.

Few studies investigate the impact of air pollution on the leading cause of infant morbidity, acute bronchiolitis. We investigated the influence of PM(2.5) and other metrics of traffic-derived air pollution exposure using a matched case-control dataset derived from 1997 to 2003 birth and infant hospitalization records from the Puget Sound Region, Washington State. Mean daily PM(2.5) exposure for 7, 30, 60 and lifetime days before case bronchiolitis hospitalization date were derived from community monitors. A regional land use regression model of NO(2) was applied to characterize subject's exposure in the month prior to case hospitalization and lifetime average before hospitalization. Subject's residential proximity within 150 m of highways, major roadways, and truck routes was also assigned. We evaluated 2604 (83%) cases and 23,354 (85%) controls with information allowing adjustment for mother's education, mother's smoking during pregnancy, and infant race/ethnicity. Effect estimates derived from conditional logistic regression revealed very modest increased risk and were not statistically significant for any of the exposure metrics in fully adjusted models. Overall, risk estimates were stronger when restricted to bronchiolitis cases attributed to respiratory syncytial virus (RSV) versus unspecified and for longer exposure windows. The adjusted odds ratio (OR(adj)) and 95% confidence interval per 10 mcg/m(3) increase in lifetime PM(2.5) was 1.14, 0.88-1.46 for RSV bronchiolitis hospitalization. This risk was also elevated for infants who resided within 150 m of a highway (OR(adj) 1.17, 0.95-1.44). This study supports a developing hypothesis that there may be a modest increased risk of bronchiolitis attributable to chronic traffic-derived particulate matter exposure particularly for infants born just before or during peak RSV season. Future studies are needed that can investigate threshold effects and capture larger variability in spatial contrasts among populations of infants.

Do environmental pollutants influence the onset of respiratory syncytial virus epidemics or disease severity?

The trigger for annual epidemics of respiratory syncytial virus (RSV) infections and the factors contributing to the disappearance of RSV infections in late winter remain obscure. Similarly, there is no adequate explanation for the higher morbidity and admission rates in industrialised as compared with rural areas. It has been suggested that a variety of environmental factors such as temperature, daylight and humidity may influence the onset and waning of the epidemics. However, the few studies assessing these variables fail to support such a link. In many tropical countries the annual epidemic occurs in the summer or autumn, arguing against temperature having a direct influence. A number of studies have suggested that indoor pollutants, including cigarette smoke, are associated with an increased likelihood of being admitted to hospital with severe lower respiratory tract disease. One study exploring the potential role of outdoor pollutants on the pattern of RSV related illness in infancy was unable to identify a clear link between a variety of pollutants and the timing of the epidemic. Nitric oxide levels were higher in winter than during the summer and much higher winter peaks of NO were observe in industrialised areas as compared with urban and rural areas. Whether this or other environmental pollutants contribute to the higher incidence of severe disease in industrialised areas is unclear. Further work is required to explore the possible influence of NO and other environmental pollutants on both the timing and severity of epidemics.

Respiratory syncytial virus infections in autologous blood and marrow transplant recipients with breast cancer: combination therapy with aerosolized ribavirin and parenteral immunoglobulins.

Scant data are available concerning the impact and response to therapy of respiratory syncytial virus (RSV) infections in patients undergoing autologous blood and marrow transplantation (BMT) for breast cancer. During eight winter seasons from 1992-1993 to 1999-2000, nine (4%) of 249 such patients were hospitalized with RSV infections. Six patients, including all five patients who were early post transplant in the pre-engraftment period, developed pneumonia and were treated with a combination of aerosolized ribavirin and IVIG. Among five patients with pneumonia in whom therapy was initiated prior to respiratory failure, one (20%) died. The sixth patient, in whom therapy was initiated after respiratory failure developed, also died. In total, two (1%) patients, both of whom were in the pre-engraftment period, died of progressive pneumonia. In conclusion, RSV is a significant cause of life-threatening pneumonia in autologous BMT recipients with breast cancer during the early post-transplant period, and accounted for a substantial portion of the overall transplant-related mortality, which in recent years has been minimal.

Pathogenesis of respiratory syncytial virus vaccine-augmented pathology.

Respiratory syncytial virus (RSV) is an important respiratory pathogen for which vaccine development has been thwarted by the legacy of vaccine-enhanced illness. A formalin-inactivated, alum-precipitated, whole virus vaccine did not protect children from infection and was associated with severe illness. Clues from clinical studies of RSV and vaccine-induced atypical measles illness suggest that an aberrant CD4+ lymphocyte response occurred in vaccinees. There is a growing body of evidence from murine models that show vaccine formulations can selectively activate different populations of CD4+ T helper lymphocytes that produce distinct cytokine expression patterns. The cytokine milieu in turn can influence the composition of the immune response and thereby impact the efficiency of virus clearance, type of pathology, and magnitude of illness. Major priorities of current vaccine development are to define the optimal combination of T lymphocyte subsets to safely clear RSV and to learn ways to modulate the composition of the immune response to vaccine antigens.