Influenza and Other Respiratory Viruses最新文献

Background: The emergence of SARS-CoV-2 and introduction of COVID-19 vaccines into immunologically naïve populations may alter the dynamics of other acute viral respiratory infections (viral ARIs) and vice versa. Competing forces, including viral interference, cross-reactive immunity, shared susceptibility, and immune dysregulation, may affect the risk. The potential net impact of various immune-priming events and their timing on the risk of viral ARIs is largely unknown.

Methods: Using data from the National Clinical Cohort Collaborative (N3C) COVID-19 Enclave, this retrospective population-based cohort study investigated the relationship between immune-priming events (COVID-19 and influenza vaccinations, and SARS-CoV-2, influenza, other, and unspecified viral ARIs) between January 2018 and September 2021 and the risk of viral ARIs during October 2021-April 2022. The sample included N = 608,725 individuals from seven data partners with well-ascertained COVID-19 and influenza vaccination data.

Results: Early COVID-19 vaccination (December 2020-March 2021) and SARS-CoV-2 infection during the overlapping period (October 2020-March 2021) were associated with a lower risk of all outcomes, including non-SARS-CoV-2 infections. Off-season influenza vaccination (January-June 2021) was associated with a lower risk of SARS-CoV-2 and any viral ARI. Other priming events showed mixed associations, with a lack of evidence of stronger protection from more recent immune-priming events.

Conclusions: This exploratory analysis suggests potential crossprotection between viral ARIs that may inform vaccination strategies. While ascertainment and healthcare-seeking biases in electronic health records may inflate positive associations between infection outcomes and immune priming, negative (i.e., protective) associations are of potential public health significance and warrant further investigation.

Background: Baloxavir marboxil, an antiviral used only in private hospitals in Hong Kong since February 2019 for treating influenza, is recognized for its efficacy against strains resistant to standard antiviral agents, providing an alternative to neuraminidase inhibitors such as oseltamivir.

Methods: This study compares the cost-effectiveness of baloxavir and oseltamivir for influenza treatment in otherwise healthy (OwH) and high-risk (HR) adult outpatients in Hong Kong from the healthcare-payer's perspective. A decision tree was utilized to study the progression of influenza and estimate associated costs and quality-adjusted life-years (QALYs) over 14 days for each antiviral.

Findings: In the general population, the incremental cost-effectiveness ratio (ICER) for baloxavir is $89,921 per QALY. Compared to oseltamivir, baloxavir shows a QALY gain with an incremental cost of $13,626 per QALY, below the $152,667 willingness-to-pay (WTP) threshold. At this WTP level, there is a 92% chance the additional cost of baloxavir is accepted. As oseltamivir resistance rises, its economic benefit decreases, while baloxavir's improves. In the OwH population, baloxavir's ICER is $145,316 compared to baseline and $115,811 compared to oseltamivir, with a 49% probability of baloxavir being cost-effective. In the HR population, baloxavir dominates, with ICERs of $36,163 and $-15,072, and a 99% probability of cost-effectiveness.

Conclusion: As a result, baloxavir could potentially be considered as the influenza agent of choice over oseltamivir in Hong Kong, despite a higher acquisition cost. Therefore, we recommended that integrating baloxavir into the Hospital Authority Drug Formulary in Hong Kong could enhance healthcare resource allocation and improve patient outcomes.

Background: Although most rhinovirus infections are mild and subside quickly, vulnerable populations may experience severe illness. Identifying populations at risk for severe or complicated rhinovirus illness can strengthen the ongoing search for preventative and therapeutic treatments. This systematic review and meta-analysis aimed to summarize the populations at risk for the development of severe or complicated rhinovirus illness.

Methods: We searched CENTRAL, EMBASE, and MEDLINE in April 2024 for studies reporting risk factors for severe rhinovirus infection, defined as lower respiratory tract infection (LRTI), hospitalization, critical care unit (CCU) admission, mechanical ventilation, or death. We pooled odds ratios using random-effects meta-analysis, assessed risk of bias using the Newcastle-Ottawa Scale, and rated the certainty of evidence using the GRADE framework.

Results: From 29 observational studies (n = 13,185 participants), we analyzed 13 risk factor-outcome combinations. With high certainty, age < 1 year and premature birth are not associated with the risk of LRTI, and diabetes mellitus is not associated with mortality. With moderate certainty, any comorbidity and pulmonary comorbidity are probably associated with increased risk of LRTI, age > 18 years and malignancy are probably associated with increased risk of mortality, and malignancy is probably associated with an increased risk of CCU admission. Many risk factors lacked sufficient evidence for meta-analysis.

Conclusions: Individuals with comorbidities are at greater risk of severe rhinovirus illness. Our findings can inform clinical risk stratification and guide the development and targeted use of emerging therapies. Further comprehensive research is required to elucidate additional risk factors and strengthen the evidence.

Background: The single radial immunodiffusion (SRID) assay is used to determine the potency of inactivated influenza vaccines. Nevertheless, development of alternative influenza vaccine potency assays with greater sensitivity and less reliance on large quantities of reference reagents is needed. Many candidate alternative potency assays use monoclonal antibodies (mAbs) to quantify the relevant immunogenic form of HA in vaccines. Although the feasibility of such assays has been demonstrated, concerns remain as to whether the necessary antibody reagents can be generated in the timeframes of vaccine manufacture, particularly for pandemic vaccines.

Methods: We describe the development and evaluation of a mAb-based ELISA assay to measure the potency of several candidate H5 clade 2.3.4.4b A/Astrakhan/3212/2020 influenza vaccines prepared recently in response to the ongoing H5N1 outbreak in the United States. The assay uses H5 mAbs that were generated and characterized several years prior to the emergence of these H5N1 viruses.

Results: Correlation of the ELISA potency results with traditional SRID potency values was excellent for a cell-based vaccine and one egg-based vaccine. The ELISA and SRID potency values for the second egg-based vaccine were not as well aligned initially, but alignment was improved by use of an internal standard.

Conclusions: The results demonstrated that the ELISA potency assay is suitable for determining the potency of inactivated H5 A/Astrakhan/3212/2020 influenza vaccines. Moreover, the results demonstrate the importance of preparing libraries of antibody reagents for influenza subtypes with pandemic potential so that suitable mAbs are available for development of alternative mAb vaccine potency assays when needed.

Purpose: This study aims to identify symptoms that predict a high likelihood of viral infection, so these patients could be triaged for home care to avoid antibiotics.

Methods: We recruited adults presenting to US primary or urgent care sites with a chief complaint of cough and symptoms consistent with LRTI. Data collected included demographics, comorbidities, symptoms, and 46 viral and bacterial respiratory pathogens by PCR. Chi-square tests were done to evaluate the association between individual symptoms and viral versus bacterial infections. Symptoms with a p < 0.10 for the association were retained for logistic regression. We created four regression models using stepwise backward elimination at p < 0.20, with viral infection, bacterial infection, and mixed infection as the dependent variables. A simple risk score was created assigning positive and negative points for viral and bacterial symptoms.

Results: We enrolled 718 adults with acute cough and obtained valid PCR specimens for 618. Four symptoms were significantly more likely with viral infections and less common in bacterial: coryza, confusion, fever, and chest congestion. Three symptoms were more likely with bacterial infections and less likely with viral infections: presence of sputum, sputum that is colored, and double-sickening (feeling better but then worsening). A simple risk score identified patients with a low (29%), moderate (56%), or high (79%) likelihood of having only viral pathogens detected.

Conclusions: Seven symptoms were identified that could help primary care clinicians distinguish between viral and bacterial LRTI. A simple risk score is proposed but requires prospective validation.