Life-Threatening Complications of Influenza versus COVID-19 in U.S. Children.

BACKGROUND: Clinical differences between critical illness from influenza infection versus coronavirus disease 2019 (COVID-19) have not been well characterized in pediatric patients. METHODS: We compared U.S. children (8 months to 17 years) admitted to the intensive care or high acuity unit with influenza (17 hospitals, 12/19/2019-3/9/2020) or COVID-19 (52 hospitals, 3/15/2020-12/31/2020). We compared demographics, underlying conditions, clinical presentation, severity, and outcomes. Using mixed-effects models, we assessed the odds of death or requiring life-support for influenza versus COVID-19 after adjustment for age, sex, race and Hispanic origin, and underlying conditions including obesity. RESULTS: Children with influenza (n = 179) were younger than those with COVID-19 (n = 381; median 5.2 vs. 13.8 years), less likely to be non-Hispanic black (14.5% vs. 27.6%) or Hispanic (24.0% vs. 36.2%), and less likely to have ≥1 underlying condition (66.4% vs. 78.5%) or be obese (21.4% vs. 42.2%). They were similarly likely to require invasive mechanical ventilation (both 30.2%), vasopressor support (19.6% and 19.9%), or extracorporeal membrane oxygenation (2.2% and 2.9%). Four children with influenza (2.2%) and 11 children with COVID-19 (2.9%) died. The odds of death or requiring life-support in children with influenza vs. COVID-19 were similar (adjusted odds ratio, 1.30 [95% CI: 0.78-2.15; P = 0.32]). Median duration of hospital stay was shorter for influenza than COVID-19 (5 versus 7 days). CONCLUSIONS: Despite differences in demographics and clinical characteristics of children with influenza or COVID-19, the frequency of life-threatening complications was similar. Our findings highlight the importance of implementing prevention measures to reduce transmission and disease severity of influenza and COVID-19.

Respiratory pathogens during the COVID-19 pandemic: Alterations in detection and seasonality in Nashville, Tennessee.

Shortly after the implementation of community mitigation measures in response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), sharp declines in respiratory syncytial virus and influenza circulation were noted; post-mitigation circulation of other respiratory pathogens has gone unexplored. We retrospectively analyzed all records of a provider-ordered multiplex test between April 1, 2018, and July 31, 2021, in Nashville, Tennessee, and we noted disrupted historical seasonal patterns for common respiratory pathogens during the SARS-CoV-2 pandemic.

Clinical presentations of adult and pediatric SARS-CoV-2-positive cases in a community cohort, Nashville, Tennessee.

Compared to adults, the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) illness in children has been lower and less severe. However, reports comparing SARS-CoV-2 infection among children and adults are limited. As part of our longitudinal cohort study of adults and children with SARS-CoV-2 infection and their household contacts in Nashville, Tennessee, we compared the clinical characteristics and outcomes of SARS-CoV-2 infections between children and adults. Children were more likely to be asymptomatically infected and had a shorter illness duration compared to adults. The differences observed in clinical presentation across ages may inform symptom-specific testing, screening, and management algorithms.

The impact of community closures among nonessential and essential workers, Nashville, Tennessee: A cross-sectional study.

Background and Aims: The effects of community closures and relaxing social distancing restrictions on severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) by occupational risk remain unclear. Therefore, we evaluated the impact of community closures and reopening phases with the prevalence of testing SARS-CoV-2-positive among nonessential and essential workers. Methods: We constructed a cross-sectional cohort from March 20 to July 31, 2020, of 344 adults from Metropolitan Nashville, Tennessee. We performed an unconditional logistic regression model to evaluate the impact of community closures and phase implementation on testing SARS-CoV-2 positive by occupation to estimate adjusted prevalence odds ratios (aPORs) and 95% confidence intervals (CIs). Results: During a stay-at-home/Phase I order, those with non-essential occupations had 59% decreased prevalence odds (aPOR:0.41; 95% CI: 0.20-0.84) of testing SARS-CoV-2-positive compared to when no restrictions were in place. Persons with essential occupations had four times the prevalence odds of testing SARS-CoV-2-positive (aPOR:4.19; 95% CI:1.57-11.18) compared with nonessential occupations when no community restrictions were established. Conclusion: Stay-at-home restrictions were associated with a lower risk of SARS-CoV-2 infection in the community for nonessential workers. Essential employees remained at increased risk for SARS-CoV-2, including when no community restrictions were in place and vaccines were not available. This study supports targeting prevention measures for these high-risk occupations.

Serological Markers of SARS-CoV-2 Reinfection.

As public health guidelines throughout the world have relaxed in response to vaccination campaigns against SARS-CoV-2, it is likely that SARS-CoV-2 will remain endemic, fueled by the rise of more infectious SARS-CoV-2 variants. Moreover, in the setting of waning natural and vaccine immunity, reinfections have emerged across the globe, even among previously infected and vaccinated individuals. As such, the ability to detect reexposure to and reinfection by SARS-CoV-2 is a key component for global protection against this virus and, more importantly, against the potential emergence of vaccine escape mutations. Accordingly, there is a strong and continued need for the development and deployment of simple methods to detect emerging hot spots of reinfection to inform targeted pandemic response and containment, including targeted and specific deployment of vaccine booster campaigns. In this study, we identify simple, rapid immune biomarkers of reinfection in rhesus macaques, including IgG3 antibody levels against nucleocapsid and FcγR2A receptor binding activity of anti-RBD antibodies, that are recapitulated in human reinfection cases. As such, this cross-species analysis underscores the potential utility of simple antibody titers and function as price-effective and scalable markers of reinfection to provide increased resolution and resilience against new outbreaks. IMPORTANCE As public health and social distancing guidelines loosen in the setting of waning global natural and vaccine immunity, a deeper understanding of the immunological response to reexposure and reinfection to this highly contagious pathogen is necessary to maintain public health. Viral sequencing analysis provides a robust but unrealistic means to monitor reinfection globally. The identification of scalable pathogen-specific biomarkers of reexposure and reinfection, however, could significantly accelerate our capacity to monitor the spread of the virus through naive and experienced hosts, providing key insights into mechanisms of disease attenuation. Using a nonhuman primate model of controlled SARS-CoV-2 reexposure, we deeply probed the humoral immune response following rechallenge with various doses of viral inocula. We identified virus-specific humoral biomarkers of reinfection, with significant increases in antibody titer and function upon rechallenge across a range of humoral features, including IgG1 to the receptor binding domain of the spike protein of SARS-CoV-2 (RBD), IgG3 to the nucleocapsid protein (N), and FcγR2A receptor binding to anti-RBD antibodies. These features not only differentiated primary infection from reexposure and reinfection in monkeys but also were recapitulated in a sequencing-confirmed reinfection patient and in a cohort of putatively reinfected humans that evolved a PCR-positive test in spite of preexisting seropositivity. As such, this cross-species analysis using a controlled primate model and human cohorts reveals increases in antibody titers as promising cross-validated serological markers of reinfection and reexposure.

Humoral and cellular immune responses to the SARS-CoV-2 BNT162b2 vaccine among a cohort of solid organ transplant recipients and healthy controls.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with increased morbidity and mortality in solid organ transplant (SOT) recipients. Despite exclusion from SARS-CoV-2 vaccine clinical trials, these individuals were identified as high-risk and prioritized for vaccination in public health guidelines. METHODS: We prospectively evaluated humoral and cellular immune responses to two doses of the SARS-CoV-2 mRNA vaccine, BNT162b2, in 56 SOT recipients and 26 healthy controls (HCs). Blood specimens collected from participants prior to each dose and following the second dose were tested for SARS-CoV-2-specific antibodies, as well as CD4+ and CD8+ T-cell responses. RESULTS: SOT recipients demonstrated lower mean anti-SARS-CoV-2 antibody levels compared to HCs after each dose, and only 21.6% achieved an antibody response after the second dose within the range of HC responses. Similarly, the percentage of responsive CD4+ and CD8+ T cells in SOT recipients was lower than in HCs. While most HCs showed notable humoral and cellular responses, responses were less concordant in SOT recipients, with some showing evidence of either humoral or cellular response, but not both. CONCLUSION: Humoral and cellular immune responses to the BNT162b2 vaccine are markedly reduced in SOT recipients as compared to HCs, suggesting that SOT recipients may benefit from more tailored regimens such as higher dose and/or additional vaccinations.

Epidemiologic trends and characteristics of SARS-CoV-2 infections among children in the United States.

PURPOSE OF REVIEW: To review the epidemiological characteristics and clinical features associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among children in the United States. RECENT FINDINGS: In the United States, the majority of SARS-CoV-2 infections in children have been mild illnesses, with those 5-17 years of age having the highest frequency. Specifically, the incidence of SARS-CoV-2 in children is two times higher in adolescents (12-17 years) than younger school-aged children (5-11 years). Despite the higher case counts in older children, 10% of pediatric hospitalizations have been in infants less than one year. In addition, severe respiratory and renal complications, hospitalization, and even death have been documented in children. SUMMARY: Clinical manifestations of SARS-CoV-2 infection in children range from asymptomatic to severe respiratory distress, with mild nonspecific symptoms being the most commonly reported. The broad clinical presentation and the frequency of asymptomatic or minimally symptomatic infections in children pose challenges for controlling and detecting SARS-CoV-2. However, severe disease has been noted in children with associated medical complications and death. Thus, additional active surveillance and research is needed to understand the burden children contribute to the SARS-CoV-2 pandemic in the United States.

Coronavirus Surveillance in a Pediatric Population in Jordan From 2010 to 2013: A Prospective Viral Surveillance Study.

BACKGROUND: Human coronaviruses (HCoVs) are a significant cause of acute respiratory illness (ARI) in children; however, the role of HCoVs in ARI among hospitalized children in the Middle East is not well defined. METHODS: Children under 2 years admitted with fever and/or respiratory symptoms were enrolled from 2010 to 2013 in Amman, Jordan. Nasal/throat swabs were collected and stored for testing. Demographic and clinical characteristics were collected through parent/guardian interviews and medical chart abstractions. Prior stored specimens were tested for HCoVs (HKU1, OC43, 229E and NL63) by qRT-PCR. RESULTS: Of the 3168 children enrolled, 6.7% were HCoVs-positive. Among HCoV-positive children, the median age was 3.8 (1.9-8.4) months, 59% were male, 14% were premature, 11% had underlying medical conditions and 76% had viral-codetection. The most common presenting symptoms were cough, fever, wheezing and shortness of breath. HCoVs were detected year-round, peaking in winter-spring months. Overall, 56%, 22%, 13% and 6% were OC43, NL63, HKU1 and 229E, respectively. There was no difference in disease severity between the species, except higher intensive care unit admission frequency in NL63-positive subjects. CONCLUSIONS: HCoVs were detected in around 7% of children enrolled in our study. Despite HCoV detection in children with ARI with highest peaks in respiratory seasons, the actual burden and pathogenic role of HCoVs in ARI merits further evaluation given the high frequency of viral codetection.