Effectiveness of COVID-19 mRNA Vaccines in Preventing COVID-19-Associated Outpatient Visits and Hospitalizations Among American Indian and Alaska Native Persons, January-November 2021: A Test-Negative Case-Control Analysis Using Surveillance Data.

Background: Despite the disproportionate morbidity and mortality experienced by American Indian and Alaska Native (AI/AN) persons during the coronavirus disease 2019 (COVID-19) pandemic, few studies have reported vaccine effectiveness (VE) estimates among these communities. Methods: We conducted a test-negative case-control analysis among AI/AN persons aged ≥12 years presenting for care from January 1, 2021, through November 30, 2021, to evaluate the effectiveness of mRNA COVID-19 vaccines against COVID-19-associated outpatient visits and hospitalizations. Cases and controls were patients with ≥1 symptom consistent with COVID-19-like illness; cases were defined as those test-positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and controls were defined as those test-negative for SARS-CoV-2. We used unconditional multivariable logistic regression to estimate VE, defined as 1 minus the adjusted odds ratio for vaccination among cases vs controls. Results: The analysis included 207 cases and 267 test-negative controls. Forty-four percent of cases and 78% of controls received 2 doses of either BNT162b2 or mRNA-1273 vaccine. VE point estimates for 2 doses of mRNA vaccine were higher for hospitalized participants (94.6%; 95% CI, 88.0-97.6) than outpatient participants (86.5%; 95% CI, 63.0-95.0), but confidence intervals overlapped. Conclusions: Among AI/AN persons, mRNA COVID-19 vaccines were highly effective in preventing COVID-associated outpatient visits and hospitalizations. Maintaining high vaccine coverage, including booster doses, will reduce the burden of disease in this population.

Human Metapneumovirus Infection in Hospitalized Children.

BACKGROUND: Most children are exposed to human metapneumovirus (HMPV) by the age of 5 y. This study aimed to describe the morbidity associated with HMPV infections in a cohort of children in the Midwest of the United States. METHODS: This was a retrospective 2-center cohort study including children (0-17 y old) hospitalized with HMPV infections at 2 tertiary care pediatric hospitals from 2009 to 2013. Demographics, chronic medical conditions, viral coinfections, and hospitalization characteristics, including the need for respiratory support, high-flow nasal cannula, CPAP, bi-level positive airway pressure, invasive mechanical ventilation, pediatric ICU admission, acute kidney injury (AKI), use of extracorporeal membrane oxygenation, and length of stay, were collected. RESULTS: In total, 131 subjects were included. Those with one or more comorbidities were older than their otherwise healthy counterparts, with a median age of 2.8 y (interquartile range [IQR] 1.1-7.0) compared to 1.3 y (IQR 0.6-2.0, P < .001), respectively. Ninety-nine (75.6%) subjects required respiratory support; 72 (55.0%) subjects required nasal cannula, simple face mask, or tracheostomy mask as their maximum support. Additionally, 1 (0.8%) subject required high-flow nasal cannula, 1 (0.8%) subject required CPAP, 2 (1.5%) subjects required bi-level positive airway pressure, 15 (11.5%) subjects required invasive mechanical ventilation, 4 (3.1%) subjects required high-frequency oscillatory or jet ventilation, and 4 (3.1%) subjects required extracorporeal membrane oxygenation. Fifty-one (38.9%) subjects required pediatric ICU admission, and 16 (12.2%) subjects developed AKI. Subjects with AKI were significantly older than those without AKI at 5.4 y old (IQR 1.6-11.7) versus 1.9 y old (IQR 0.7-3.5, P = .003). After controlling for the presence of at least one comorbidity and cystic fibrosis, each year increase in age led to a 16% increase in the odds of AKI (P = .01). The median length of stay for the entire cohort was 4.0 d (IQR 2.7-7.0). CONCLUSIONS: Children hospitalized with HMPV may be at risk for AKI. Risk of HMPV-associated AKI appears to increase with age regardless of severity of respiratory illness or presence of comorbidities.

The role of human metapneumovirus in the critically ill adult patient.

PURPOSE: The purpose of the study is to describe the role of human metapneumovirus (hMPV) infection in critical illness and acute respiratory distress syndrome (ARDS). MATERIALS AND METHODS: We collected clinical and demographic information from a retrospective chart review, comparing patients with and without an intensive care unit (ICU) admission. Among patients admitted to the ICU, we assessed whether hMPV was "unlikely," "possibly," or "likely" the reason for ICU admission, based on a prespecified definition, and whether the patient met criteria for ARDS. RESULTS: We identified 128 hospitalized adults with hMPV infection. Forty hospitalized patients (31%) with hMPV infection required admission to the ICU. Among patients cared for in the ICU, hMPV was "possibly" the reason for ICU admission in 55% of patients and "likely" the reason in 38%. Forty-eight percent of ICU patients met criteria for ARDS. Although most patients admitted to the ICU had significant comorbidities or were immunosuppressed, 6 patients requiring ICU admission had more minor comorbidities and no underlying immunosuppression. CONCLUSIONS: Although most patients hospitalized with hMPV had chronic cardiac or pulmonary disease, hMPV can also be associated serious respiratory illness and ARDS in adult patients without significant comorbidities or immunosuppression.