Reported cases of multisystem inflammatory syndrome in children aged 12-20 years in the USA who received a COVID-19 vaccine, December, 2020, through August, 2021: a surveillance investigation.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory condition associated with antecedent SARS-CoV-2 infection. In the USA, reporting of MIS-C after vaccination is required under COVID-19 vaccine emergency use authorisations. We aimed to investigate reports of individuals aged 12-20 years with MIS-C after COVID-19 vaccination reported to passive surveillance systems or through clinician outreach to the US Centers for Disease Control and Prevention (CDC). METHODS: In this surveillance activity, we investigated potential cases of MIS-C after COVID-19 vaccination reported to CDC's MIS-C national surveillance system, the Vaccine Adverse Event Reporting System (co-administered by CDC and the US Food and Drug Administration), and CDC's Clinical Immunization Safety Assessment Project. A multidisciplinary team adjudicated cases by use of the CDC MIS-C definition. Any positive SARS-CoV-2 serology test satisfied case criteria; although anti-nucleocapsid antibodies indicate previous SARS-CoV-2 infection, anti-spike protein antibodies indicate either past or recent infection or COVID-19 vaccination. We describe the demographic and clinical features of cases, stratified by laboratory evidence of SARS-CoV-2 infection. To calculate the reporting rate of MIS-C, we divided the count of all individuals meeting the MIS-C case definition, and of those without evidence of SARS-CoV-2 infection, by the number of individuals aged 12-20 years in the USA who received one or more COVID-19 vaccine doses up to Aug 31, 2021, obtained from CDC national vaccine surveillance data. FINDINGS: Using surveillance results from Dec 14, 2020, to Aug 31, 2021, we identified 21 individuals with MIS-C after COVID-19 vaccination. Of these 21 individuals, median age was 16 years (range 12-20); 13 (62%) were male and eight (38%) were female. All 21 were hospitalised: 12 (57%) were admitted to an intensive care unit and all were discharged home. 15 (71%) of 21 individuals had laboratory evidence of past or recent SARS-CoV-2 infection, and six (29%) did not. As of Aug 31, 2021, 21 335 331 individuals aged 12-20 years had received one or more doses of a COVID-19 vaccine, making the overall reporting rate for MIS-C after vaccination 1·0 case per million individuals receiving one or more doses in this age group. The reporting rate in only those without evidence of SARS-CoV-2 infection was 0·3 cases per million vaccinated individuals. INTERPRETATION: Here, we describe a small number of individuals with MIS-C who had received one or more doses of a COVID-19 vaccine before illness onset; the contribution of vaccination to these illnesses is unknown. Our findings suggest that MIS-C after COVID-19 vaccination is rare. Continued reporting of potential cases and surveillance for MIS-C illnesses after COVID-19 vaccination is warranted. FUNDING: US Centers for Disease Control and Prevention.

Multisystem Inflammatory Syndrome after SARS-CoV-2 Infection and COVID-19 Vaccination.

We report 3 patients in California, USA, who experienced multisystem inflammatory syndrome (MIS) after immunization and severe acute respiratory syndrome coronavirus 2 infection. During the same period, 3 adults who were not vaccinated had MIS develop at a time when ≈7% of the adult patient population had received >1 vaccine.

Wheezing in children with pertussis associated with delayed pertussis diagnosis.

BACKGROUND: The classic clinical features of paroxysmal pertussis are often absent in older children and adults and after vaccination. The California pertussis epidemic of 2010 occurred in a highly vaccinated population. METHODS: All pediatric patients (0-18 years) with positive pertussis polymerase chain reaction from July to December 2010 were identified retrospectively from the Kaiser SCAL database. Information extracted by chart review included age at diagnosis, vaccine history, race, cough duration, number of clinic visits before diagnosis, presence of paroxysms, post-tussive emesis or wheezing, treatment for asthma during the course of illness and exposure to confirmed or suspected pertussis cases. RESULTS: Overall 501 pediatric patients (mean age = 8.4 years) with positive pertussis nasopharyngeal polymerase chain reaction were identified. Complete DTaP series and Tdap vaccine had been received by 93% and 38% of eligible patients, respectively. Paroxysms, post-tussive emesis and wheezing on physical examination were present in 34%, 30% and 8% of patients, respectively. Each was associated with a longer duration of symptoms at diagnosis. Wheezing was associated with a delay in diagnosis (60% requiring >1 clinic visit for diagnosis vs. 29% in the overall population, P < 0.0001). Documented exposures were associated with a more timely pertussis diagnosis (after 9.4 days vs. 14.5 days; P < 0.0001). CONCLUSIONS: Wheezing is present on examination of some patients with pertussis in a highly vaccinated pediatric population and appears to delay the diagnosis of pertussis. The presence of wheezing should not be used to exclude this diagnosis in children with chronic cough or other reasons to suspect pertussis.

Excessive oral zinc supplementation.

The use of megadoses of vitamin and mineral supplements has become common. The authors describe a 17-year-old boy who presented with fatigue after taking large daily doses of zinc supplements for 6 to 7 months in an attempt to treat his acne. A zinc-induced hypocupremia developed, causing anemia, leukopenia, and neutropenia. Anemia and neutropenia resolved 6 months after he stopped taking the zinc. Excessive zinc intake can have toxic effects, and questions about patients' use of vitamin and mineral supplements should be asked when medication histories are taken.