Anti-Spike Antibodies Present in the Milk of SARS-CoV-2 Vaccinated Mothers Are Complement-Activating

Although only 0.8–1% of SARS-CoV-2 infections are in the 0–9 age-group, pneumonia is still the leading cause of infant mortality globally. Antibodies specifically directed against SARS-CoV-2 spike protein (S) are produced during severe COVID-19 manifestations. Following vaccination, specific antibodies are also detected in the milk of breastfeeding mothers. Since antibody binding to viral antigens can trigger activation of the complement classical - pathway, we investigated antibody-dependent complement activation by anti-S immunoglobulins (Igs) present in breast milk following SARS-CoV-2 vaccination. This was in view of the fact that complement could play a fundamentally protective role against SARS-CoV-2 infection in newborns. Thus, 22 vaccinated, lactating healthcare and school workers were enrolled, and a sample of serum and milk was collected from each woman. We first tested for the presence of anti-S IgG and IgA in serum and milk of breastfeeding women by ELISA. We then measured the concentration of the first subcomponents of the three complement pathways (i.e., C1q, MBL, and C3) and the ability of anti-S Igs detected in milk to activate the complement in vitro. The current study demonstrated that vaccinated mothers have anti-S IgG in serum as well as in breast milk, which is capable of activating complement and may confer a protective benefit to breastfed newborns.

Shaping the subway microbiome through probiotic-based sanitation during the COVID-19 emergency: a pre-post case-control study.

BACKGROUND: The COVID-19 pandemic has highlighted the extent to which the public transportation environment, such as in subways, may be important for the transmission of potential pathogenic microbes among humans, with the possibility of rapidly impacting large numbers of people. For these reasons, sanitation procedures, including massive use of chemical disinfection, were mandatorily introduced during the emergency and remain in place. However, most chemical disinfectants have temporary action and a high environmental impact, potentially enhancing antimicrobial resistance (AMR) of the treated microbes. By contrast, a biological and eco-sustainable probiotic-based sanitation (PBS) procedure was recently shown to stably shape the microbiome of treated environments, providing effective and long-term control of pathogens and AMR spread in addition to activity against SARS-CoV-2, the causative agent of COVID-19. Our study aims to assess the applicability and impact of PBS compared with chemical disinfectants based on their effects on the surface microbiome of a subway environment. RESULTS: The train microbiome was characterized by both culture-based and culture-independent molecular methods, including 16S rRNA NGS and real-time qPCR microarray, for profiling the train bacteriome and its resistome and to identify and quantify specific human pathogens. SARS-CoV-2 presence was also assessed in parallel using digital droplet PCR. The results showed a clear and significant decrease in bacterial and fungal pathogens (p < 0.001) as well as of SARS-CoV-2 presence (p < 0.01), in the PBS-treated train compared with the chemically disinfected control train. In addition, NGS profiling evidenced diverse clusters in the population of air vs. surface while demonstrating the specific action of PBS against pathogens rather than the entire train bacteriome. CONCLUSIONS: The data presented here provide the first direct assessment of the impact of different sanitation procedures on the subway microbiome, allowing a better understanding of its composition and dynamics and showing that a biological sanitation approach may be highly effective in counteracting pathogens and AMR spread in our increasingly urbanized and interconnected environment. Video Abstract.

Anti-Spike Antibodies Present in the Milk of SARS-CoV-2 Vaccinated Mothers Are Complement-Activating.

Although only 0.8-1% of SARS-CoV-2 infections are in the 0-9 age-group, pneumonia is still the leading cause of infant mortality globally. Antibodies specifically directed against SARS-CoV-2 spike protein (S) are produced during severe COVID-19 manifestations. Following vaccination, specific antibodies are also detected in the milk of breastfeeding mothers. Since antibody binding to viral antigens can trigger activation of the complement classical - pathway, we investigated antibody-dependent complement activation by anti-S immunoglobulins (Igs) present in breast milk following SARS-CoV-2 vaccination. This was in view of the fact that complement could play a fundamentally protective role against SARS-CoV-2 infection in newborns. Thus, 22 vaccinated, lactating healthcare and school workers were enrolled, and a sample of serum and milk was collected from each woman. We first tested for the presence of anti-S IgG and IgA in serum and milk of breastfeeding women by ELISA. We then measured the concentration of the first subcomponents of the three complement pathways (i.e., C1q, MBL, and C3) and the ability of anti-S Igs detected in milk to activate the complement in vitro. The current study demonstrated that vaccinated mothers have anti-S IgG in serum as well as in breast milk, which is capable of activating complement and may confer a protective benefit to breastfed newborns.

Cytokine Profiles as Potential Prognostic and Therapeutic Markers in SARS-CoV-2-Induced ARDS.

BACKGROUND: Glucocorticoids (GCs) have been shown to reduce mortality and the need for invasive mechanical ventilation (IMV) in SARS-CoV-2-induced acute respiratory distress syndrome (ARDS). It has been suggested that serum cytokines levels are markers of disease severity in ARDS, although there is only limited evidence of a relationship between the longitudinal cytokine profile and clinical outcomes in patients with SARS-CoV-2-induced ARDS treated with GC. METHODS: We conducted a single-center observational study to investigate serial plasma cytokine levels in 17 patients supported with non-invasive ventilation (NIV) in order to compare the response in five patients who progressed to IMV versus 12 patients who continued with NIV alone. All patients received methylprednisolone 80 mg/day continuous infusion until clinical improvement. RESULTS: The study groups were comparable at baseline. All patients survived. Although IL-6 was higher in the NIV group at baseline, several cytokines were significantly higher in the IMV group on day 7 (IL-6, IL-8, IL-9, G-CSF, IP-10, MCP-1, MIP-1α) and 14 (IL-6, IL-8, IL-17, G-CSF, MIP-1α, RANTES). No significant differences were observed between groups on day 28. CONCLUSIONS: Patients in the IMV group had higher inflammation levels at intubation than the NIV group, which may indicate a higher resistance to glucocorticoids. Higher GC doses or a longer treatment duration in these patients might have allowed for a better control of inflammation and a better outcome. Further studies are required to define the prognostic value of cytokine patterns, in terms of both GC treatment tailoring and timely initiation of IMV.

Cytokine Profiles as Potential Prognostic and Therapeutic Markers in SARS-CoV-2-Induced ARDS

Background. Glucocorticoids (GCs) have been shown to reduce mortality and the need for invasive mechanical ventilation (IMV) in SARS-CoV-2-induced acute respiratory distress syndrome (ARDS). It has been suggested that serum cytokines levels are markers of disease severity in ARDS, although there is only limited evidence of a relationship between the longitudinal cytokine profile and clinical outcomes in patients with SARS-CoV-2-induced ARDS treated with GC. Methods. We conducted a single-center observational study to investigate serial plasma cytokine levels in 17 patients supported with non-invasive ventilation (NIV) in order to compare the response in five patients who progressed to IMV versus 12 patients who continued with NIV alone. All patients received methylprednisolone 80 mg/day continuous infusion until clinical improvement. Results. The study groups were comparable at baseline. All patients survived. Although IL-6 was higher in the NIV group at baseline, several cytokines were significantly higher in the IMV group on day 7 (IL-6, IL-8, IL-9, G-CSF, IP-10, MCP-1, MIP-1α) and 14 (IL-6, IL-8, IL-17, G-CSF, MIP-1α, RANTES). No significant differences were observed between groups on day 28. Conclusions. Patients in the IMV group had higher inflammation levels at intubation than the NIV group, which may indicate a higher resistance to glucocorticoids. Higher GC doses or a longer treatment duration in these patients might have allowed for a better control of inflammation and a better outcome. Further studies are required to define the prognostic value of cytokine patterns, in terms of both GC treatment tailoring and timely initiation of IMV.

Spread of Respiratory Pathogens During the COVID-19 Pandemic Among Children in the Northeast of Italy.

The social distancing measures adopted during the coronavirus disease 2019 (COVID-19) pandemic led to a profound change in the behavioral habits of the population. This study analyzes the impact of restriction measures on the shaping of the epidemiology of common winter respiratory pathogens in the pediatric population of northeast of Italy. From August 2020 to March 2021, a total of 1,227 nasopharyngeal swabs from symptomatic pediatric patients were tested for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A and B, adenovirus, other coronaviruses, parainfluenza virus 1-4, enterovirus, bocavirus, metapneumovirus, respiratory syncytial virus, rhinovirus, Bordetella pertussis, Bordetella parapertussis, and Mycoplasma pneumoniae. To relate virus positivity with the clinic characteristics of the subjects enrolled, multinomial logistic models were estimated. SARS-CoV-2 was detected in 5.2% of the children; fever resulted as risk factor for infection [relative risk ratio (RRR) = 2.88, p = 0.034]. Rhinovirus was detected in the 40.7% of the subjects, with cough and rhinitis as risk factors (respectively, RRR = 1.79, p = 0.001 and RRR = 1.53, p = 0.018). Other coronaviruses were found in 10.8% of children and were associated to pharyngodynia (RRR = 4.94, p < 0.001). Adenovirus, observed in 11.6% of subjects, showed to have fever as risk factor (RRR = 6.44, p < 0.001). Bocavirus was detected in 3.2% of children. In conclusion, our results showed that social isolation measures had an impact on the circulation of RSV and influenza, although children under the age of 2 were most affected by the other respiratory infections. Therefore, this study highlights the need for continuing surveillance for a delayed spread of RSV and other respiratory pathogens.

Introduction of Probiotic-Based Sanitation in the Emergency Ward of a Children's Hospital During the COVID-19 Pandemic.

Background: Antimicrobial resistance (AMR) represents a major threat to public health, especially in the hospital environment, and the massive use of disinfectants to prevent COVID-19 transmission might intensify this risk, possibly leading to future AMR pandemics. However, the control of microbial contamination is crucial in hospitals, since hospital microbiomes can cause healthcare-associated infections (HAIs), which are particularly frequent and severe in pediatric wards due to children having high susceptibility. Aim: We have previously reported that probiotic-based sanitation (PCHS) could stably decrease pathogens and their AMR in the hospital environment, reduce associated HAIs in adult hospitals, and inactivate enveloped viruses. Here, we aimed to test the effect of PCHS in the emergency room (ER) of a children's hospital during the COVID-19 pandemic. Methods: Conventional chemical disinfection was replaced by PCHS for 2 months during routine ER sanitation; the level of environmental bioburden was characterized before and at 2, 4, and 9 weeks after the introduction of PCHS. Microbial contamination was monitored simultaneously by conventional culture-based CFU count and molecular assays, including 16S rRNA NGS for bacteriome characterization and microarrays for the assessment of the resistome of the contaminating population. The presence of SARS-CoV-2 was also monitored by PCR. Results and conclusions: PCHS usage was associated with a stable 80% decrease in surface pathogens compared to levels detected for chemical disinfection (P < 0.01), accompanied by an up to 2 log decrease in resistance genes (Pc < 0.01). The effects were reversed when reintroducing chemical disinfection, which counteracted the action of the PCHS. SARS-CoV-2 was not detectable in both the pre-PCHS and PCHS periods. As the control of microbial contamination is a major issue, especially during pandemic emergencies, collected data suggest that PCHS may be successfully used to control virus spread without simultaneous worsening of the AMR concern.

Circulation of SARS-CoV-2 Variants among Children from November 2020 to January 2022 in Trieste (Italy).

INTRODUCTION: The ongoing coronavirus disease 19 (COVID-19) outbreak involves the pediatric population, but to date, few reports have investigated the circulation of variants among children. MATERIAL AND METHODS: In this retrospective study, non-hospitalized pediatric patients with SARS-CoV-2-positive nasopharyngeal swabs (NPS) were enrolled at the Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste (Italy), from November 2020 to January 2022. SARS-CoV-2 variants were identified by in vitro viral isolation, amplification, automatic sequencing of the receptor binding domain (RBD) of the SARS-CoV-2 spike coding gene, and subsequent next-generation sequencing. The growth curves of the isolated strains were defined in vitro by infecting Vero-E6 cells and quantifying the viral load in the supernatants up to 72 h post-infection by qRT-PCR. The neutralization activity of sera obtained from a COVID-19 vaccinated subject, recovered (2020) patient, vaccinated and recovered (2021) patient, and seronegative subject was assessed by microneutralization assay against the different variants. RESULTS: In total, 32 SARS-CoV-2-positive children, 16 (50%) females, with a median age of 1.4 years (range: 1 day-13 years), were enrolled. The D614G amino acid substitution was detected in all isolated and amplified viral strains. Of the 32 isolates, 4 (12.5%) carried a nonsynonymous nucleotide mutation leading to the N439K (3/4), lineage B.1.258 (∆H69/∆V70), and S477N (1/4) substitution. In 7/32 (21.8%) isolates, amino acid substitutions allowed the identification of a delta variant, lineage B.1.617.2-AY.43, and in 1/32 (3.1%), the Omicron strain (B.1.1.529.BA1) was identified. The growth curves of the B.1, B.1.258 (∆H69/∆V70), B.1.617.2-AY.43, and B.1.1.529.BA1 variants did not show any significant differences. A reduction in the serum neutralizing activity against B.1.258 (∆H69/∆V70) only in a vaccinated subject (1.7-fold difference), against B.1.617.2-AY.43 in a vaccinated subject and in recovered patients (12.7 and ≥2.5-fold differences, respectively), and against B.1.1.529.BA1 variant (57.6- and 1.4-fold differences in vaccinated and in vaccinated and recovered patients) were observed compared to the B.1 variant. CONCLUSIONS: SARS-CoV-2 variants carrying the B.1.258 (∆H69/∆V70) and S477N substitutions were reported here in a pediatric population for the first time. Although the growth rates of the isolated strains (B.1.258, B.1.617.2-AY.43, B.1.1.529.BA1) did not differ from the B.1 variant, neutralizing activity of the sera from vaccinated subjects significantly decreased against these variants. Attention should be devoted to the pediatric population to prevent the spread of new SARS-CoV-2 variants in an unvaccinated and predominantly naive population.

Evolution of SARS-CoV-2 IgG Seroprevalence in Children and Factors Associated with Seroconversion: Results from a Multiple Time-Points Study in Friuli-Venezia Giulia Region, Italy.

Data on the effective burden of the SARS-CoV-2 pandemic in the pediatric population are limited. We aimed at assessing the prevalence of SARS-CoV-2 IgG antibodies in children at three subsequent time-points. The study was conducted between January 2021 and July 2021 among children referring to the Research Institute for Maternal and Child Health "Burlo Garofolo" in Trieste, a referral regional hospital in Friuli Venezia Giulia, Italy. A multivariate analysis was conducted to assess factors independently associated with seroconversion. A total of 594 children were included. Anti-SARS-CoV-2 trimeric Spike protein IgG antibodies were found in 32 (15.4%) children tested in April-May and in 20 (11.8%) in June-July 2021, compared with 24 (11.1%) of those tested in January-February 2021 (p = 0.37, Armitage exact test for trend over time p = 0.76). A subgroup analysis and a multivariate logistic regression analysis were performed considering sociodemographic, clinical, and historical variables. Three categories of children showed statistically significant increased odds of positive anti-SARS-CoV-2 IgG antibodies: children previously positive to a nasopharyngeal swab (AdjOR 15.41, 95%CI 3.44-69.04, p < 0.001), cohabitant with a person with an history of a previous positive nasopharyngeal swab (AdjOR 9.95, 95%CI 5.35-18.52, p < 0.001), and children with a foreign citizenship (AdjOR 2.4, 95%CI 1.05-5.70, p = 0.002). The study suggests that seroprevalence studies may be of limited help in estimating the prevalence of the COVID-19 pandemic in children. Further studies are needed to identify other markers of previous SARS-CoV-2 infection in children, such as CD4+ T cells or memory B-cells.

IgG and IgA Antibodies Post SARS-CoV-2 Vaccine in the Breast Milk and Sera of Breastfeeding Women.

The COVID-19 pandemic has carried massive global health and economic burden that is currently counteracted by a challenging anti-COVID-19 vaccination campaign. Indeed, mass vaccination against COVID-19 is expected to be the most efficacious intervention to mitigate the pandemic successfully. The primary objective of the present study is to test the presence of neutralizing anti-SARS-CoV-2 antibodies (IgA and IgG) in the breast milk and sera samples from vaccinated women at least 20 days after the complete vaccine cycle. A secondary aim is to compare the IgG antibodies level in maternal serum and breast milk. The third target is to evaluate the presence of the IgG antibodies in breast milk after several weeks from the vaccination. Finally, we collected information on the health status of infants in the days following maternal vaccination. Forty-two mothers were enrolled in the study. Thirty-six received the Pfizer/BioNTech vaccine, four the Astra Zeneca vaccine, one the Moderna vaccine and another woman Astra Zeneca in the first dose and Pfizer/BioNTech in the second dose. All 42 milk samples confirmed the presence of anti-SARS-CoV-2 IgG, and none showed IgA presence. Regarding the matched 42 sera samples, 41 samples detected IgG presence, with one sample testing negative and only one positive for seric IgA. None of the 42 infants had fever or changes in sleep or appetite in the seven days following the maternal vaccination. The level of IgG antibodies in milk was, on average, lower than that in maternal serum. According to our analysis, the absence of IgA could suggest a rapid decrease after vaccination even if frequent breastfeeding could favour its persistence. IgG were present in breast milk even 4 months after the second vaccine dose. Information on the immunological characteristics of breast milk could change mothers' choices regarding breastfeeding.

SARS-CoV-2 Infection and Inflammatory Response in a Twin Pregnancy.

There is growing literature about the SARS-CoV-2 pathogenetic effects exerted during pregnancy and whether vertical transmission or premature birth is possible. It is not well known whether changes in the immune system of pregnant women may lead to a marked susceptibility to infectious processes and the risk of adverse maternal and neonatal complications such as preterm birth, spontaneous abortion, hospitalization in an intensive care unit, transmission to the fetus or newborns, and fetal mortality are poorly understood. Along with this ongoing debate, it is not well defined whether, during pregnancy, the role of host susceptibility in producing a specific inflammatory response to SARS-CoV-2 may represent distinctive markers of risk of vertical transmission. Furthermore, SARS-CoV-2 impact on the vaginal microbiome has not yet been described, despite mounting evidence on its possible effect on the gastrointestinal microbiome and its influence on infectious diseases and preterm labor. This report describes the impact of SARS-CoV-2 on a twin pregnancy diagnosed with infection at the third trimester of gestation including tissue infections, inflammatory response, antibody production, cytokine concentration, and vaginal microbiome composition. We identified a pattern of cytokines including IL1-Ra, IL-9 G-CSF, IL-12, and IL-8 differently expressed, already associated with previously infected patients. We detected a similar concentration of almost all the cytokines tested in both twins, suggesting that the SARS-CoV-2-induced cytokine storm is not substantially impaired during the placental passage. The analysis of the vaginal microbiome did not show relevant signs of dysbiosis, similar to other healthy pregnant women and twin healthy pregnancies. The aim of this report was to analyze the immunological response against SARS-CoV-2 infection and virus tissue tropism in a twin pregnancy.

Profiling of Oral Microbiota and Cytokines in COVID-19 Patients.

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been recently demonstrated in the sputum or saliva, suggesting how the shedding of viral RNA outlasts the end of symptoms. Recent data from transcriptome analysis show that the oral cavity mucosa harbors high levels of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease, serine 2 (TMPRSS2), highlighting its role as a double-edged sword for SARS-CoV-2 body entrance or interpersonal transmission. Here, we studied the oral microbiota structure and inflammatory profile of 26 naive severe coronavirus disease 2019 (COVID-19) patients and 15 controls by 16S rRNA V2 automated targeted sequencing and magnetic bead-based multiplex immunoassays, respectively. A significant diminution in species richness was observed in COVID-19 patients, along with a marked difference in beta-diversity. Species such as Prevotella salivae and Veillonella infantium were distinctive for COVID-19 patients, while Neisseria perflava and Rothia mucilaginosa were predominant in controls. Interestingly, these two groups of oral species oppositely clustered within the bacterial network, defining two distinct Species Interacting Groups (SIGs). COVID-19-related pro-inflammatory cytokines were found in both oral and serum samples, along with a specific bacterial consortium able to counteract them. We introduced a new parameter, named CytoCOV, able to predict COVID-19 susceptibility for an unknown subject at 71% of power with an Area Under Curve (AUC) equal to 0.995. This pilot study evidenced a distinctive oral microbiota composition in COVID-19 subjects, with a definite structural network in relation to secreted cytokines. Our results would be usable in clinics against COVID-19, using bacterial consortia as biomarkers or to reduce local inflammation.

Prevalence of SARS-CoV-2 infection in Italian pediatric population: a regional seroepidemiological study.

BACKGROUND: Data on the effective burden of the SARS-CoV-2 pandemic in pediatric population are very limited, mostly because of the higher rate of asymptomatic or paucisymptomatic cases among children. Updated data on COVID-19 prevalence are needed for their relevance in public health and for infection control policies. In this single-centre cross-sectional study we aimed to assess prevalence of SARS-CoV-2 infection through IgG antibodies detection in an Italian pediatric cohort. METHODS: The study was conducted in January 2021 among both inpatients and outpatients referring to Research Institute for Maternal and Child Health "Burlo Garofolo" in Trieste, Friuli Venezia-Giulia, Italy, who needed for blood test for any reason. Collected samples were sent to Italian National Institute of Health for analysis through chemiluminescent immunoassay (CLIA). RESULTS: One hundred sixty-nine patients were included in the study, with a median age of 10.5 ± 4.1 years, an equal distribution for sex (49.7% female patients), and a 55.6% prevalence of comorbidities. Prevalence of anti-SARS-CoV-2 trimeric Spike protein IgG antibodies was 9.5% (n = 16), with a medium titre of 482.3 ± 387.1 BAU/mL. Having an infected cohabitant strongly correlated with IgG positivity (OR 23.83, 95% CI 7.19-78.98, p < 0.0001), while a cohabitant healthcare worker wasn't associated with a higher risk (OR 1.53, 95% CI 0.4-5.86, p 0.46). All of the 5 patients who had previously tested positive to a nasopharyngeal swab belonged to the IgG positive group, with a 3-month interval from the infection at most. CONCLUSION: We assessed a 9.5% SARS-CoV-2 seroprevalence in a pediatric cohort from Friuli Venezia-Giulia region in January 2021, showing a substantial increase after the second peak of the pandemic occurred starting from October 2020, compared to 1% prevalence observed by National Institute of Statistics (ISTAT) in July 2020.

Case Report: Use of Anakinra in Multisystem Inflammatory Syndrome During COVID-19 Pandemic.

During COVID-19 outbreak, a large number of children with severe inflammatory disease has been reported. This condition, named Pediatric Multi-inflammatory Syndrome temporally associated with COVID-19 (PIMS-TS) or Multisystem Inflammatory Syndrome associated with Coronavirus Disease 2019 (MIS-C), shares some clinical features with Kawasaki disease and is frequently complicated by myocarditis or shock. It has been suggested that MIS-C belongs to the group of cytokine storm syndromes triggered by SARS-CoV-2 infection. So far, intravenous immunoglobulin (IVIG) and systemic glucocorticoids are the most common therapeutic approaches reported in this group of patients. However, the use of anakinra in patients with severe forms of COVID-19 is showing promising results. Here we reported two patients with multisystem inflammatory syndrome complicated with shock. Both the patients presented a poor response to IVIG and systemic glucocorticoids and received anakinra. Treatment with IL-1 receptor antagonist showed a rapid improvement of clinical conditions and biochemical analysis in both patients and demonstrated a good safety profile. Thus, we look forward for future controlled clinical trials with the aim to demonstrate the effectiveness of anakinra in patients with MIS-C and established precise criteria for its use.