IMPORTANCEVaccination against COVID-19 provides clear public health benefits, but vaccination also carries potential risks. The risks and outcomes of myocarditis after COVID-19 vaccination are unclear.OBJECTIVE To describe reports of myocarditis and the reporting rates after mRNA-based COVID-19 vaccination in the US. DESIGN, SETTING, AND PARTICIPANTS Descriptive study of reports of myocarditis to the Vaccine Adverse Event Reporting System (VAERS) that occurred after mRNA-based COVID-19 vaccine administration between December 2020 and August 2021 in 192 405 448 individuals older than 12 years of age in the US; data were processed by VAERS as of September 30, 2021. EXPOSURES Vaccination with BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna).MAIN OUTCOMES AND MEASURES Reports of myocarditis to VAERS were adjudicated and summarized for all age groups. Crude reporting rates were calculated across age and sex strata. Expected rates of myocarditis by age and sex were calculated using 2017-2019 claims data. For persons younger than 30 years of age, medical record reviews and clinician interviews were conducted to describe clinical presentation, diagnostic test results, treatment, and early outcomes. RESULTS Among 192 405 448 persons receiving a total of 354 100 845 mRNA-based COVID-19 vaccines during the study period, there were 1991 reports of myocarditis to VAERS and 1626 of these reports met the case definition of myocarditis. Of those with myocarditis, the median age was 21 years (IQR, 16-31 years) and the median time to symptom onset was 2 days (IQR, 1-3 days). Males comprised 82% of the myocarditis cases for whom sex was reported. The crude reporting rates for cases of myocarditis within 7 days after COVID-19 vaccination exceeded the expected rates of myocarditis across multiple age and sex strata. The rates of myocarditis were highest after the second vaccination dose in adolescent males aged 12 to 15 years (70.7 per million doses of the BNT162b2 vaccine), in adolescent males aged 16 to 17 years (105.9 per million doses of the BNT162b2 vaccine), and in young men aged 18 to 24 years (52.4 and 56.3 per million doses of the BNT162b2 vaccine and the mRNA-1273 vaccine, respectively). There were 826 cases of myocarditis among those younger than 30 years of age who had detailed clinical information available; of these cases, 792 of 809 (98%) had elevated troponin levels, 569 of 794 (72%) had abnormal electrocardiogram results, and 223 of 312 (72%) had abnormal cardiac magnetic resonance imaging results. Approximately 96% of persons (784/813) were hospitalized and 87% (577/661) of these had resolution of presenting symptoms by hospital discharge. The most common treatment was nonsteroidal anti-inflammatory drugs (589/676; 87%). CONCLUSIONS AND RELEVANCEBased on passive surveillance reporting in the US, the risk of myocarditis after receiving mRNA-based COVID-19 vaccines was increased across multiple age and sex strata and was highest after the second vaccination dose in adolescent males and young men. This risk should be ...

The US 2010-2011 influenza vaccines were moderately effective in preventing medically attended influenza during a season when all 3 vaccine strains were antigenically similar to circulating viruses. Continued monitoring of influenza vaccines in all age groups is important, particularly as new vaccines are introduced.

Risk factors for vancomycin-resistant enterococcal (VRE) bloodstream infection (BSI) were studied at a tertiary-care hospital by comparing 46 patients with VRE-BSI with 46 randomly selected patients with vancomycin-susceptible enterococcal (VSE) BSI. Among patients with an enterococcal BSI, risk factors for mortality were determined. Independent risk factors for VRE-BSI were increasing APACHE II score (odds ratio [OR], 2.3/5-point increase; 95% confidence interval [CI], 1.4-3.9), receipt of vancomycin (OR, 11; 95% CI, 5.5-21), or diagnosis of hematologic malignancy (OR, 8.4; 95% CI, 3.9-18). After controlling for APACHE II score and gender, patients with VRE- versus VSE-BSI did not have a significantly elevated risk of mortality (OR, 3.3; 95% CI, 0.7-15). Five of 28 VRE blood isolates typed using pulsed-field gel electrophoresis had identical banding patterns. These data suggest that increasing severity of illness, underlying disease, and receipt of vancomycin are major risk factors for VRE-BSI.

ABSTRACT. Objective. High incidence, rising admission rates, and relatively ineffective therapies make the management of bronchiolitis controversial. Since 1980, the rate of hospitalization for children with bronchiolitis has increased by nearly 250%, whereas mortality rates for the disease have remained constant. It has been speculated that the increasing use of pulse oximetry has lowered the threshold for admission and may have contributed to the rise in bronchiolitis-related admissions. The objective of this study was to describe pediatric emergency medicine physicians' management preferences regarding infants with moderately severe bronchiolitis and to assess the influence of specific differences in oxygen saturation as measured by pulse oximetry (SpO 2 ) and respiratory rate (RR) on the decision to admit.Methods. Physicians who are members of the American Academy of Pediatrics Section of Emergency Medicine and living in the United States were randomized into 4 groups and mailed a survey that contained 1 of 4 vignettes. Vignettes were identical except for given SpO 2 values (94% or 92%) and RR (50/min or 65/min). Subjects were asked to answer questions regarding laboratory tests, treatment options, and the decision to admit for the patient in their vignette.Results. We received completed surveys from 519 (64%) of the 812 physicians contacted. Most respondents recommended use of bronchodilators (96%), nasal suction (82%), and supplemental oxygen (57%). Few respondents recommended decongestants (9%), steroids (8%), or antibiotics (2%). When asked to rank therapies, respondents gave nasal suction 182 number 1 votes; bronchodilators received 164. The decision to admit varied with SpO 2 and RR. Forty-three percent of respondents who received a vignette featuring SpO 2 of 94% and a RR of 50/min recommended admission for the infant in their vignette. Fifty-eight percent recommended admission when the vignette SpO 2 was 94% and RR was 65/min ( 2 ‫؍‬ 5.021). Respondents who received a vignette with SpO 2 of 92% were nearly twice as likely to recommend admission: 83% recommended admission when vignette RR was 50/min, and 85% recommended admission when vignette RR was 65/min ( 2 ‫؍‬ 0.126).Conclusions. When treating infants with moderately severe bronchiolitis, pediatricians who work in emergency departments frequently use bronchodilators and nasal suction, 2 practices for which supporting data are either conflicting (bronchodilators) or nonexistent (nasal suction). In addition, their decisions to admit differ markedly on the basis of only a 2% difference in SpO 2 . It is possible that increased reliance on pulse oximetry has contributed to the increase in bronchiolitis hospitalization rates seen during the past 2 decades. Pediatrics 2003;111:e45-e51. URL: http://www.pediatrics.org/cgi/ content/full/111/1/e45; bronchiolitis, bronchodilators, steroids, nasal suction, pulse oximetry, practice variation.ABBREVIATIONS. Spo 2 , oxygen saturation as measured by pulse oximetry; RR, respiratory rate; RSV, respiratory syncytial...

among the three COVID-19 vaccines authorized for use in the United States, only the Pfizer-BioNTech BNT162b2 mRNA COVID-19 vaccine is authorized for adolescents aged 12-17 years. The Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for Pfizer-BioNTech vaccine for use in persons aged ≥16 years on December 11, 2020 (1); the EUA was expanded to include adolescents aged 12-15 years on May 10, 2021 (2), based on results from a Phase 3 clinical trial (3). Beginning in June 2021, cases of myocarditis and myopericarditis (hereafter, myocarditis) after receipt of Pfizer-BioNTech vaccine began to be reported, primarily among young males after receipt of the second dose (4,5). On June 23, 2021, CDC's Advisory Committee on Immunization Practices (ACIP) reviewed available data and concluded that the benefits of COVID-19 vaccination to individual persons and the population outweigh the risks for myocarditis and recommended continued use of the vaccine in persons aged ≥12 years (6). To further characterize safety of the vaccine, adverse events after receipt of Pfizer-BioNTech vaccine reported to the Vaccine Adverse Event Reporting System (VAERS) and adverse events and health impact assessments reported in v-safe (a smartphone-based safety surveillance system) were reviewed for U.S. adolescents aged 12-17 years during December 14, 2020-July 16, 2021. As of July 16, 2021, approximately 8.9 million U.S. adolescents aged 12-17 years had received Pfizer-BioNTech vaccine.* VAERS received 9,246 reports after Pfizer-BioNTech vaccination in this age group; 90.7% of these were for nonserious adverse events and 9.3% were for serious adverse events, including myocarditis (4.3%). Approximately 129,000 U.S. adolescents aged 12-17 years enrolled in v-safe * https://covid.cdc.gov/covid-data-tracker/#datatracker-home after Pfizer-BioNTech vaccination; they reported local (63.4%) and systemic (48.9%) reactions with a frequency similar to that reported in preauthorization clinical trials. Systemic reactions were more common after dose 2. CDC and FDA continue to monitor vaccine safety and provide data to ACIP to guide COVID-19 vaccine recommendations.VAERS is a passive vaccine safety surveillance system comanaged by CDC and FDA that monitors adverse events after vaccination (7). VAERS accepts reports from anyone, including health care providers, vaccine manufacturers, and members of the public. Under COVID-19 vaccine EUA requirements, health care providers must report certain adverse events after vaccination to VAERS, including death. † Signs, symptoms, and diagnostic findings in VAERS reports are assigned Medical Dictionary for Regulatory Activities (MedDRA) preferred terms by VAERS staff members. § VAERS reports are classified as serious if any of the following are reported: † https://vaers.hhs.gov/faq.html § Each VAERS report might be assigned more than one MedDRA preferred term.

On April 30, 2021, this report was posted as an MMWR Early Release on the MMWR website (https://www.cdc.gov/mmwr).On February 27, 2021, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for Janssen (Ad.26.COV2.S) COVID-19 vaccine (Janssen Biotech, Inc., a Janssen Pharmaceutical company, Johnson & Johnson) (1). The Janssen COVID-19 vaccine, the third COVID-19 vaccine authorized for use in the United States, uses a replication-incompetent human adenoviral type 26 vector platform* (2) and is administered as a single intramuscular dose, whereas the first two authorized vaccines use an mRNA platform and require 2 doses. On February 28, 2021, the Advisory Committee on Immunization Practices (ACIP) issued interim recommendations for use of Janssen COVID-19 vaccine among persons aged ≥18 years (3). During April 13-23, CDC and FDA recommended a pause in use of Janssen vaccine after reports of six cases of cerebral venous sinus thrombosis (CVST) with thrombocytopenia (platelet count <150,000/µL of blood) among Janssen vaccine recipients (4). Similar thrombotic events, primarily among women aged <60 years, have been described in Europe after receipt of the AstraZeneca COVID-19 vaccine, which uses a replication-incompetent chimpanzee adenoviral vector (5-7). The U.S. CVST cases that prompted the pause in Janssen vaccination, as well as subsequently detected CVST cases, are described elsewhere (8). This report summarizes adverse events among Janssen vaccine recipients, including non-CVST cases of thrombosis with thrombocytopenia syndrome (TTS), reported to the Vaccine Adverse Events Reporting System (VAERS), a passive surveillance system, and through v-safe, an active monitoring system. As of April 21, 2021, 7.98 million doses of the Janssen COVID-19 vaccine had been administered. Among 13,725 VAERS reports reviewed, 97% were classified as nonserious and 3% as serious, † including three reports among women of cases of thrombosis in large arteries or veins accompanied by thrombocytopenia during the second week after vaccination. These three cases and the previously detected CVST cases are * The Janssen COVID-19 vaccine contains double-stranded DNA encoding a variant of the SARS-CoV-2 spike glycoprotein inserted into a replicationincompetent human adenovirus type 26 virus. † VAERS reports are classified as serious if any of the following are reported: death, life-threatening illness, hospitalization or prolongation of hospitalization, permanent disability, congenital anomaly, or birth defect.

Enhanced infection-control strategies reduced VRE transmission in an oncology unit in which VRE were endemic.

VLBW and LBW infants are at increased risk of dying with bronchiolitis, even when taking into account other risk factors. Although infants weighing <2500 g at birth are at increased risk for dying with bronchiolitis, the majority of bronchiolitis deaths occur among infants of normal birth weight.