Rare predicted loss-of-function variants of type I IFN immunity genes are associated with critical COVID-19 (preprint)

Background We previously reported inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity in 1-5% of unvaccinated patients with life-threatening COVID-19, and autoantibodies against type I IFN in another 15-20% of cases. Methods We report here a genome-wide rare variant burden association analysis in 3,269 unvaccinated patients with life-threatening COVID-19 (1,301 previously reported and 1,968 new patients), and 1,373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. A quarter of the patients tested had antibodies against type I IFN (234 of 928) and were excluded from the analysis. Results No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI:1.5-528.7, P=1.1x10-4), in analyses restricted to biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70 [95%CI:1.3-8.2], P=2.1x10-4). Adding the recently reported TYK2 COVID-19 locus strengthened this enrichment, particularly under a recessive model (OR=19.65 [95%CI:2.1-2635.4]; P=3.4x10-3). When these 14 loci and TLR7 were considered, all individuals hemizygous (n=20) or homozygous (n=5) for pLOF or bLOF variants were patients (OR=39.19 [95%CI:5.2-5037.0], P=4.7x10-7), who also showed an enrichment in heterozygous variants (OR=2.36 [95%CI:1.0-5.9], P=0.02). Finally, the patients 13 with pLOF or bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P=1.68x10-5). Conclusions Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie lifethreatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Consensus on COVID-19 vaccination in pediatric oncohematological patients, on behalf of infectious working group of Italian Association of Pediatric Hematology Oncology (preprint)

Vaccines represent the best tool to prevent the severity course and fatal consequences of pandemic by new Coronavirus 2019 infection (SARS CoV 2). Considering the limited data on vaccination of pediatric oncohematological patients, we develop a Consensus document to support the Italian pediatric hematological oncological (AIEOP) centers in a scientifically correct communication with families and patients and to promote vaccination. The topics of the Consensus were: SARS CoV 2 infection and disease (COVID 19) in the pediatric subject s; COVID 19 vaccines (type, schedule); which and when to vaccinate; contraindications and risk of serious adverse events; rare adverse events; third dose and vaccination after COVID 19; and other general prevention measures. Using the Delphi methodology fo r Consensus, 21 statements and their corresponding rationale were elaborated and discussed with the representatives of 31 centers, followed by voting. AIEOP Centers showed an overall agreement on all the statements that were therefore approved. This consensus document highlights that children and adolescents affected by hematological and oncological diseases are a fragile category. Vaccination plays an important role to prevent COVID19, to permit the regular administration of chemotherapy or other treatmen ts, to perform control visits and hospital admissions, and to prevent treatment delays.