Myocarditis following COVID-19 mRNA vaccinations: Twin and sibling case series.

ImportanceMyocarditis and myopericarditis are well described adverse events of special interest (AESI) following COVID-19 vaccinations. Whilst the aetiology is still being investigated; there is evidence that genetic predisposition may be a risk factor for the development of myocarditis. Furthermore, hormones are thought to contribute to sex-specific differences in myocarditis, skewed toward a larger risk in adolescent males. Objective: This unique sibling case series may help highlight potential mechanisms and prognostic factors in the development of myocarditis following COVID-19 vaccination in adolescent males. In this context, twin and familial studies provide a unique epidemiological perspective to investigate the interplay between genetic predisposition and other factors. Participants: Observational case series of all siblings reported to SAEFVIC with chest pain following COVID-19 vaccinations in Victoria, Australia. Exposure: mRNA vaccination (Comirnaty BNT162b2 COVID-19 (Pfizer-BioNTech) and Spikevax mRNA-1273 (Moderna). Findings: Our case series comprises 6 young males; two sets of monozygotic twins and one set of fraternal brothers following reports of chest pain associated with COVID-19 mRNA vaccination. Five patients were diagnosed with myocarditis as per Brighton Collaboration Criteria (Level 2). The remaining sibling, who did not have myocarditis, was subsequently diagnosed with pubertal delay. Conclusions: Understanding the genetic and hormonal risk factors and aetiology for myocarditis associated with COVID-19 vaccines is paramount. Further evaluation of specific genetic targets or biomarkers is required to understand the implications of population vaccine policy, particularly for adolescent and young adult males at highest risk for this AESI.

Acute disseminated encephalomyelitis and routine childhood vaccinations - a self-controlled case series.

Acute disseminated encephalomyelitis (ADEM) is an autoimmune, central nervous system demyelinating disorder that follows antecedent immunologic challenges, such as infection or vaccination. This study aimed to investigate the potential association between routine childhood vaccinations and ADEM. Children under 7 years of age admitted to the two tertiary level pediatric hospitals in Victoria, Australia with ADEM from 2000-2015 had their clinical information linked to vaccination records from the Australian Childhood Immunization Register. Chart review was undertaken utilizing the Brighton Collaboration ADEM criteria. The self-controlled case-series (SCCS) methodology was employed to determine the relative incidences of ADEM post-vaccination in two risk intervals: 5-28 days and 2-42 days. Forty-six cases were eligible for SCCS analysis with a median age of 3.2 years. Of the forty-six cases, three were vaccine proximate cases and received vaccinations 23, 25 and 28 days before ADEM onset. Two vaccine proximate cases received their 4-year-old scheduled vaccinations (MMR and DTPa-IPV) and one vaccine proximate case the 1-year old scheduled vaccinations (MMR and Hib-MenC). The relative incidence of ADEM during the narrow and broad risk intervals were 1.041 (95% CI 0.323-3.356, p = 0.946) and 0.585 (95% CI 0.182-1.886, p = 0.370) respectively. Sensitivity analyses did not yield any substantial deviations. These results do not provide evidence of an association between vaccinations routinely provided to children aged under 7 years in Australia and the incidence of ADEM. However, these results should be interpreted with caution as the number of ADEM cases identified was limited and further research is warranted.

Timing of routine infant vaccinations and risk of food allergy and eczema at one year of age.

BACKGROUND: Epidemiological evidence suggests that routine vaccinations can have nontargeted effects on susceptibility to infections and allergic disease. Such effects may depend on age at vaccination, and a delay in pertussis vaccination has been linked to reduced risk of allergic disease. We aimed to test the hypothesis that delay in vaccines containing diphtheria-tetanus-acellular pertussis (DTaP) is associated with reduced risk of food allergy and other allergic diseases. METHODS: HealthNuts is a population-based cohort in Melbourne, Australia. Twelve-month-old infants were skin prick-tested to common food allergens, and sensitized infants were offered oral food challenges to determine food allergy status. In this data linkage study, vaccination data for children in the HealthNuts cohort were obtained from the Australian Childhood Immunisation Register. Associations were examined between age at the first dose of DTaP and allergic disease. RESULTS: Of 4433 children, 109 (2.5%) received the first dose of DTaP one month late (delayed DTaP). Overall, delayed DTaP was not associated with primary outcomes of food allergy (adjusted odds ratio (aOR) 0.77; 95% CI: 0.36-1.62, P = 0.49) or atopic sensitization (aOR: 0.66; 95% CI: 0.35-1.24, P = 0.19). Amongst secondary outcomes, delayed DTaP was associated with reduced eczema (aOR: 0.57; 95% CI: 0.34-0.97, P = 0.04) and reduced use of eczema medication (aOR: 0.45; 95% CI: 0.24-0.83, P = 0.01). CONCLUSIONS: There was no overall association between delayed DTaP and food allergy; however, children with delayed DTaP had less eczema and less use of eczema medication. Timing of routine infant immunizations may affect susceptibility to allergic disease.

Australian immunisation registers: established foundations and opportunities for improvement.

The National Immunisation Program Schedule in Australia is formulated and funded nationally under the population-wide Medicare system. The policy is implemented by the eight state and territory jurisdictions. The national immunisation registers consist of the Australian Childhood Immunisation Register (ACIR), and, more recently, the National Human Papillomavirus (HPV) Vaccination Program Register. Moreover, a variety of jurisdiction-based registers and primary care practice software systems exist, which interact with the national registers. General practitioners can obtain reports listing patients under seven years attending their practice and recorded as 'not fully immunised', and immunisation coverage rates for their practice linked to government incentives through Medicare. A 2011 report documents national coverage of 91.8% fully immunised at 12 months, and 92.6% at 24 months. The HPV register provides information on vaccination coverage with the potential to link with a register of cervical cancer screening results. Limitations of current national register include inability to easily access immunisation histories beyond seven years of age, and issues of underreporting and timeliness, which impact significantly the immunisation coverage estimates. The linkage of these registers with healthcare outcome data will further enhance public health outcomes by enabling rapid, population-level vaccine safety and effectiveness investigations in a nation with a track record as an 'early adopter' of new childhood vaccines.

Comparison of complementary and alternative medicine use: reasons and motivations between two tertiary children's hospitals.

AIMS: To compare prevalence, reasons, motivations, initiation, perceived helpfulness, and communication of complementary and alternative medicine (CAM) use between two tertiary children's hospitals. METHODOLOGY: A study, using a face-to-face questionnaire, of 500 children attending the University Hospital of Wales, Cardiff, UK was compared to an identical study of 503 children attending the Royal Children's Hospital, Melbourne, Australia. RESULTS: One year CAM use in Cardiff was lower than Melbourne (41% v 51%; OR = 0.67, 95% CI 0.52-0.85), reflected in non-medicinal use (OR = 0.41, 95% CI 0.29-0.58) and general paediatric outpatients (OR = 0.38, 95% CI 0.21-0.67). Compared to Melbourne, factors associated with lower CAM use in Cardiff included families born locally (father: OR = 0.58, 95% CI 0.44-0.77) or non-tertiary educated parents (mother: OR = 0.54, 95% CI 0.38-0.77). Cardiff participants used less vitamin C (OR = 0.31, 95% CI 0.18-0.51) and herbs (OR = 0.49, 95% CI 0.34-0.71), attended less chiropractors (OR = 0.25, 95% CI 0.06-0.37) and naturopaths (OR = 0.08, 95% CI 0.02-0.33), but saw more reflexologists (OR = 3.33, 95% CI 1.08-10.29). In Cardiff, CAM was more popular for relaxation (OR = 1.92, 95% CI 1.03-3.57) but less for colds/coughs (OR = 0.4, 95% CI 0.27-0.73). Most CAM was self-initiated (by parent) in Cardiff and Melbourne (74% v 70%), but Cardiff CAM users perceived it less helpful (OR = 0.46, 95% CI 0.31-0.68). Non-disclosure of CAM use was high in Cardiff and Melbourne (66% v 63%); likewise few doctors/nurses documented recent medicinal CAM use in inpatient notes (0/21 v 2/22). CONCLUSIONS: The differences in CAM use may reflect variation in sociocultural factors influencing reasons, motivations, attitudes, and availability. The regional variation in use and poor communication highlights the importance of local policy development.