SARS-CoV-2 Vaccinated Breakthrough Infections With Fatal and Critical Outcomes in the Department of Antioquia, Colombia

The introduction of variants of concern and interest in the Departamento of Antioquia, Colombia, was concomitant with the beginning of the COVID-19 immunization program. Genomic surveillance indicates that none of the emerging variants –alpha, gamma, lambda, mu or delta– were dominant between January and August 2021. The immunization includes CoronaVac, BNT162b2, Ad26.COV2.S and ChAdOx1-S vaccines. By September 10th, 34.43% inhabitants were fully vaccinated. We characterized, SARS-CoV-2 breakthrough infections in 96 patients, 30 with fatal outcomes, 13 with ICU hospitalization and 53 with mild or asymptomatic disease. Even though gamma and mu variants co-circulated at similar levels, the latter was found to be predominant in patients with fatal outcomes and in those with ICU hospitalizations. We found a significant occurrence of the B.1.625 variant in these patients. Genetic substitutions of therapeutic and immunological concern, E484K and N501Y, are consistently observed in 90.1% and 79.5% of these variants, respectively. Evidence suggests that it is less probable to become infected after 60 days post-treatment with BNT162b2 than with CoronaVac. Importantly, we found that advanced age and comorbidities foster conditions for fatal and ICU outcomes in vaccinated patients. Our observations demonstrate the effectiveness of vaccination and identify patients with higher risks of subsequent breakthrough infections.

Experimental Chlamydia gallinacea infection in chickens does not protect against a subsequent experimental Chlamydia psittaci infection

Chlamydia psittaci was considered the predominant chlamydial species in poultry until Chlamydia gallinacea was discovered in 2009. C. psittaci is a zoonotic obligate intracellular bacterium reported in more than 465 bird species including poultry. In poultry, infections can result in asymptomatic disease, but also in more severe systemic illness. The zoonotic potential of C. gallinacea has yet to be proven. Infections in poultry appear to be asymptomatic and in recent prevalence studies C. gallinacea was the main chlamydial species found in chickens. The high prevalence of C. gallinacea resulted in the question if an infection with C. gallinacea might protect against an infection with C. psittaci. To investigate possible cross protection, chickens were inoculated with C. gallinacea NL_G47 and subsequently inoculated with either a different strain of C. gallinacea (NL_F725) or C. psittaci. Chickens that had not been pre-inoculated with C. gallinacea NL_G47 were used as a C. gallinacea or C. psittaci infection control. In the groups that were inoculated with C. psittaci, no difference in pharyngeal or cloacal shedding, or in tissue dissemination was observed between the control group and the pre-inoculated group. In the groups inoculated with C. gallinacea NL_F725, shedding in cloacal swabs and tissues dissemination was lower in the group pre-inoculated with C. gallinacea NL_G47. These results indicate previous exposure to C. gallinacea does not protect against an infection with C. psittaci, but might protect against a new infection of C. gallinacea.

The Role of PF4 Antibodies in Pediatric Sars-Cov-2 Infections

Background The ChAdOx1 nCoV-19 vaccine has been shown to induce Vaccine-induced Immune Thrombotic Thrombocytopenia (VITT), a syndrome that shares clinical features with heparin-induced thrombocytopenia (HIT). The mechanism of thrombocytopenia and thrombosis in these disorders appears to be related to the development of pathologic anti-PF4/heparin antibodies, some of which could activate complement. Interestingly, we and others have found that complement activation is vital when both pediatric and adult patients have severe respiratory illness from SARS-CoV-2 virus (COVID-19) or in the post-infectious multisystem inflammatory syndrome in children (MIS-C). We hypothesized that patients with severe COVID-19 or MIS-C develop similar anti-PF4/heparin antibodies, which lead to endothelial complement activation that drive the inflammatory responses seen in these diseases. Methods Our cohort included 30 pediatric patients with positive SARS-CoV-2 RT-PCRs: 10 each of severe COVID-19 ("Severe", MIS-C, and mild/asymptomatic ("Mild") infection. Using ELISA, we evaluated the levels of antibodies to various platelet-related proteins including PF4, PF4-heparin, and NAP2; in addition, we examined the ability of plasma from each patient to activate complement. The antibody levels were compared to control samples including samples from adult patients with VITT and HIT. Statistical analyses with ANOVA were performed to evaluate differences. Results Patients with MIS-C have a significantly higher anti-PF4 antibody concentration (as measured by mean optical density [OD]) than patients with either mild/asymptomatic disease, or severe COVID-19: Severe 0.5 +/- 0.14; Mild 0.3 +/- 0.12; MIS-C 0.77 +/- 0.35, p=0.003 MIS-C vs. Mild); Similar results were seen for anti-PF4/heparin antibodies: Severe 0.4 +/- 0.14; Mild 0.35 +/- 0.12; MIS-C 0.64 +/- 0.3, p=0.003 MIS-C vs. Mild; p=0.034 MIS-C vs. Severe). These were similar to values obtained for the HIT sample (Figure). Conclusion Patients with MIS-C and severe COVID19 have significant detectable anti-PF4 and PF4/heparin antibodies in contrast to those patients with mild/asymptomatic disease. Our previous studies have shown that patients with MIS-C and COVID-19 have evidence of endovascular complement activation in the form of elevated soluble membrane attack complex (sC5-b9). We have also previously demonstrated that VITT anti-PF4 and anti-PF4/heparin antibodies activate complement and result in endothelial cell activation. These antibodies in pediatric SARS-CoV-2 infection may be involved in the development of more severe disease manifestations. Ongoing investigations will identify if this is due to endothelial complement activation and inflammatory responses that accompany severe disease. This is the first demonstration of the role of anti-PF4 and PF4/heparin antibodies in pediatric SARS-CoV-2. Figure 1 Figure 1. Disclosures Bassiri: Guidepoint Global: Consultancy; Kriya Therapeutics: Consultancy, Current holder of individual stocks in a privately-held company. Teachey: Janssen: Consultancy; NeoImmune Tech: Research Funding; Sobi: Consultancy; BEAM Therapeutics: Consultancy, Research Funding. Lambert: ClinGen, ISTH, ASH, GW University: Honoraria; Rigel: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy; Dova: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Shionogi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Argenx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Principia: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra Zeneca: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Sysmex: Research Funding; PDSA: Research Funding; Octapharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Children and Adults in a Household Cohort Study Have Robust Longitudinal Immune Responses Following SARS-CoV-2 Infection or Exposure

Children have reduced severity of COVID-19 compared to adults and typically have mild or asymptomatic disease. The immunological mechanisms underlying these age-related differences in clinical outcomes remain unexplained. Here, we quantify 23 immune cell populations in 141 samples from children and adults with mild COVID-19 and their PCR-negative close household contacts at acute and convalescent time points. Children with COVID-19 displayed marked reductions in myeloid cells during infection, most prominent in children under the age of five. Recovery from infection in both children and adults was characterised by the generation of CD8 TCM and CD4 TCM up to 9 weeks post infection. SARS-CoV-2-exposed close contacts also had immunological changes over time despite no evidence of confirmed SARS-CoV-2 infection on PCR testing. This included an increase in low-density neutrophils during convalescence in both exposed children and adults, as well as increases in CD8 TCM and CD4 TCM in exposed adults. In comparison to children with other common respiratory viral infections, those with COVID-19 had a greater change in innate and T cell-mediated immune responses over time. These findings provide new mechanistic insights into the immune response during and after recovery from COVID-19 in both children and adults.

Early Detection of ARI Disease and First Aid in Children with Fever Seizures at Posyandu Cadres at Kantil Depok, Sleman

Background: Acute Respiratory Infection (ARI) is one of the problems of death in children in developing countries. ARI is an upper or lower respiratory tract disease, usually contagious, which can cause a wide spectrum of disease that ranges from asymptomatic disease or mild infection to severe and deadly disease.Objective: Yandu cadres can improve knowledge, attitudes and skills in handling ARI and febrile seizures in children, so as to optimize growth and development in children optimally.Methods: socialization and simulation of the handling of ARI and febrile seizures in children through cadres. Cadres were given material about ARI and febrile seizures, followed by interactive activities about the steps taken to overcome/handle ARI and febrile seizures in children. The cadres were divided into three groups and accompanied by one trainer.Results: the cadres stated that they understood, and seemed capable of handling febrile seizures in children.Suggestion: The existence of counseling and training to parents/mothers about ARI and handling febrile seizures in children, providing first aid kits and simple medicines for handling febrile seizures at Posyandu, also in families who have children and often experience febrile seizures under the supervision of a doctor, it is necessary the existence of socialization in physical form contains the importance of handling febrile seizures in children.

Early Detection of ARI Disease and First Aid in Children with Fever Seizures at Posyandu Cadres at Kantil Depok, Sleman

Background: Acute Respiratory Infection (ARI) is one of the problems of death in children in developing countries. ARI is an upper or lower respiratory tract disease, usually contagious, which can cause a wide spectrum of disease that ranges from asymptomatic disease or mild infection to severe and deadly disease.Objective: Yandu cadres can improve knowledge, attitudes and skills in handling ARI and febrile seizures in children, so as to optimize growth and development in children optimally.Methods: socialization and simulation of the handling of ARI and febrile seizures in children through cadres. Cadres were given material about ARI and febrile seizures, followed by interactive activities about the steps taken to overcome/handle ARI and febrile seizures in children. The cadres were divided into three groups and accompanied by one trainer.Results: the cadres stated that they understood, and seemed capable of handling febrile seizures in children.Suggestion: The existence of counseling and training to parents/mothers about ARI and handling febrile seizures in children, providing first aid kits and simple medicines for handling febrile seizures at Posyandu, also in families who have children and often experience febrile seizures under the supervision of a doctor, it is necessary the existence of socialization in physical form contains the importance of handling febrile seizures in children.

Blood Transcriptomes of Anti-SARS-CoV-2 Antibody-Positive Healthy Individuals Who Experienced Asymptomatic Versus Clinical Infection

The reasons behind the clinical variability of SARS-CoV-2 infection, ranging from asymptomatic infection to lethal disease, are still unclear. We performed genome-wide transcriptional whole-blood RNA sequencing, bioinformatics analysis and PCR validation to test the hypothesis that immune response-related gene signatures reflecting baseline may differ between healthy individuals, with an equally robust antibody response, who experienced an entirely asymptomatic (n=17) versus clinical SARS-CoV-2 infection (n=15) in the past months (mean of 14 weeks). Among 12.789 protein-coding genes analysed, we identified six and nine genes with significantly decreased or increased expression, respectively, in those with prior asymptomatic infection relatively to those with clinical infection. All six genes with decreased expression (IFIT3, IFI44L, RSAD2, FOLR3, PI3, ALOX15), are involved in innate immune response while the first two are interferon-induced proteins. Among genes with increased expression six are involved in immune response (GZMH, CLEC1B, CLEC12A), viral mRNA translation (GCAT), energy metabolism (CACNA2D2) and oxidative stress response (ENC1). Notably, 8/15 differentially expressed genes are regulated by interferons. Our results suggest that subtle differences at baseline expression of innate immunity-related genes may be associated with an asymptomatic disease course in SARS-CoV-2 infection. Whether a certain gene signature predicts, or not, those who will develop a more efficient immune response upon exposure to SARS-CoV-2, with implications for prioritization for vaccination, warrant further study.

Undiagnosed Case of Klippel-Trenaunnay Syndrome Presenting as Extensive Heterotrophic Ossification and Flexion Deformity of Right Lower Limb Requiring Amputation : A Case Report

Klippel-Trenaunnay Syndrome is a rare disease characterized by a clinical triad of capillary malformation, soft tissue and bony hypertrophy, and atypical varicosity. This syndrome ranges from asymptomatic disease to life-threatening bleeding, embolism, and deformities. Management includes early diagnosis, prevention, and treatment of complications. We present a case of a 43-year-old male presenting with pain, swelling and deformity of the right leg for 30 years. On examination, diffusely enlarged tender right limb with several dark patchy discolorations, multiple tortuous vessels were found. Right leg X-ray showed heterotrophic ossification and distortion of ankle joint. Due to chronic severe pain, recurrent infection, contracture and flexion deformity of right leg, the patient underwent above knee amputation. This case focuses on the variable presentation and multiple problems faced by patients with Klippel-Trenaununay Syndrome as they get diagnosed late and shows the importance of high index of suspicion for early diagnosis and prevention of complications.

Duration of SARS-CoV-2 sero-positivity in a large longitudinal sero-surveillance cohort: the COVID-19 Community Research Partnership

Background Estimating population prevalence and incidence of prior SARS-CoV-2 infection is essential to formulate public health recommendations concerning the COVID-19 pandemic. However, interpreting estimates based on sero-surveillance requires an understanding of the duration of elevated antibodies following SARS-CoV-2 infection, especially in the large number of people with pauci-symptomatic or asymptomatic disease. Methods We examined > 30,000 serology assays for SARS-CoV-2 specific IgG and IgM assays acquired longitudinally in 11,468 adults between April and November 2020 in the COVID-19 Community Research Partnership. Results Among participants with serologic evidence for infection but few or no symptoms or clinical disease, roughly 50% sero-reverted in 30 days of their initial positive test. Sero-reversion occurred more quickly for IgM than IgG and for antibodies targeting nucleocapsid protein compared with spike proteins, but was not associated with age, sex, race/ethnicity, or healthcare worker status. Conclusions The short duration of antibody response suggests that the true population prevalence of prior SARS-CoV-2 infection may be significantly higher than presumed based on earlier sero-surveillance studies. The impact of the large number of minimally symptomatic COVID-19 cases with only a brief antibody response on population immunity remains to be determined.

Deep immune profiling of the maternal-fetal interface with mild SARS-CoV-2 infection

ABSTRACTPregnant women are an at-risk group for severe COVID-19, though the majority experience mild/asymptomatic disease. Although severe COVID-19 has been shown to be associated with immune activation at the maternal-fetal interface even in the absence of active viral replication, the immune response to asymptomatic/mild COVID-19 remains unknown. Here, we assessed immunological adaptations in both blood and term decidua from 9 SARS-exposed pregnant women with asymptomatic/mild disease and 15 pregnant SARS-naive women. In addition to selective loss of tissue-resident decidual macrophages, we report attenuation of antigen presentation and type I IFN signaling but upregulation of inflammatory cytokines and chemokines in blood monocyte derived decidual macrophages. On the other hand, infection was associated with remodeling of the T cell compartment with increased frequencies of activated CD69+ tissue-resident T cells and decreased abundance of Tregs. Interestingly, frequencies of cytotoxic CD4 and CD8 T cells increased only in the blood, while CD8 effector memory T cells were expanded in the decidua. In contrast to decidual macrophages, signatures of type I IFN signaling were increased in decidual T cells. Finally, T cell receptor diversity was significantly reduced with infection in both compartments, albeit to a much greater extent in the blood. The resulting aberrant immune activation in the placenta, even with asymptomatic disease may alter the exquisitely sensitive developing fetal immune system, leading to long-term adverse outcomes for offspring.