Persistent SARS-CoV-2 infection with multiple clinical relapses in two patients with follicular lymphoma treated with bendamustine and obinutuzumab or rituximab.

PURPOSE: People with hematologic malignancies have a significantly higher risk of developing severe and protracted forms of SARS-CoV-2 infection compared to immunocompetent patients, regardless of vaccination status. RESULTS: We describe two cases of prolonged SARS-CoV-2 infection with multiple relapses of COVID-19 pneumonia in patients with follicular lymphoma treated with bendamustine and obinutuzumab or rituximab. The aim is to highlight the complexity of SARS-CoV-2 infection in this fragile group of patients and the necessity of evidence-based strategies to treat them properly. CONCLUSIONS: Patients with hematological malignancies treated with bendamustine and anti-CD20 antibodies had a significant risk of prolonged and relapsing course of COVID-19. Specific preventive and therapeutic strategies should be developed for this group of patients.

Acute respiratory infection emergency access in a tertiary care children hospital in Italy, prior and after the SARS-CoV-2 emergence.

Background: The COVID-19 pandemic has changed the epidemiology of acute respiratory infections (ARIs) in children. The aims of the present study were to describe the epidemiological trend of ARI emergency visits and virology results prior and after the SARS-CoV-2 emergence and to estimate the association of ARI emergency department (ED) visits with respiratory viruses. Methods: This study was conducted at the Bambino Gesù Children's Hospital, a tertiary care children's hospital in the Lazio Region, Italy. The demographic and clinical information of children who accessed the ED and were diagnosed with ARI from January 1, 2018 to June 30, 2022 was retrospectively extracted from the electronic health records. The observed temporal trends in viruses diagnosed from respiratory samples were compared with the number of ARI ED visits over the same period through a multivariable linear regression model. Results: During the study period, there were 72,959 ED admissions for ARIs and 33,355 respiratory samples resulted positive for viruses. Prior to the pandemic, respiratory syncytial virus (RSV) and influenza had a clear seasonal pattern, which was interrupted in 2020. In 2021-2022, RSV reached the highest peak observed during the study period, whereas influenza activity was minimal. The peaks of ARI ED visits corresponded to peaks of influenza, RSV, and rhinovirus in the 2018-2019 and 2019-2020 seasons, to SARS-CoV-2 and rhinovirus in 2020, and to RSV and parainfluenza in 2021-2022. Conclusions: ARI resulting in ED visits should be included in the ARI disease burden measurement for a more accurate measure of the impact of preventive measures.

Pre-existing immunity to SARS-CoV-2 before the COVID-19 pandemic era in Cameroon: A comparative analysis according to HIV-status.

Background: The lower burden of COVID-19 in tropical settings may be due to preexisting cross-immunity, which might vary according to geographical locations and potential exposure to other pathogens. We sought to assess the overall prevalence of SARS-CoV-2 antibodies and determine SARS-CoV-2 seropositivity according to HIV-status before the COVID-19 pandemic era. Methods: A cross-sectional and comparative study was conducted at the Chantal BIYA International Reference Centre (CIRCB) on 288 stored plasma samples (163 HIV-positive versus 125 HIV-negative); all collected in 2017-2018, before the COVID-19 pandemic era. Abbott Panbio™ COVID-19 IgG/IgM assay was used for detecting SARS-CoV-2 immunoglobulin G (IgG) and M (IgM). Among people living with HIV (PLHIV), HIV-1 viral load and TCD4 cell count (LTCD4) were measured using Abbott Real Time PCR and BD FACSCalibur respectively. Statistical analyses were performed, with p<0.05 considered statistically significant. Results: The median [IQR] age was 25 [15-38] years. Overall seropositivity to SARS-CoV-2 antibodies was 13.5% (39/288) of which 7.3% (21) was IgG, 7.3% (21) IgM and 1.0% (3) IgG/IgM. According to HIV-status in the study population, SARS-CoV-2 seropositivity was 11.0% (18/163) among HIV-positive versus 16.8% (21/125) among HIV-negative respectively, p=0.21. Specifically, IgG was 6.1% (10/163) versus 8.8% (11/125), p=0.26; IgM was 5.5% (9/163) versus 9.6%, (12/125), p=0.13 and IgG/IgM was 0.6% (1/163) versus 1.6% (2/125) respectively. Among PLHIV, SARS-CoV-2 seropositivity according to CD4 count was 9.2% (≥500 cells/µL) versus 1.8% (200-499 cells/µL), (OR=3.5; p=0.04) and 0.6% (<200 cells/µL), (OR=17.7; p<0.01). According to viral load, SARS-CoV-2 seropositivity was 6.7% (≥40 copies/mL) versus 4.9% (<40 copies/mL), (OR= 3.8; p<0.01). Conclusion: Before COVID-19 in Cameroon, cross-reactive antibodies to SARS-CoV-2 were in circulation, indicating COVID-19 preexisting immunity. This preexisting immunity may contribute in attenuating disease severity in tropical settings like Cameroon. Of relevance, COVID-19 preexisting immunity is lower with HIV-infection, specifically with viral replication and poor CD4-cell count. As poor CD4-count leads to lower cross-reactive antibodies (regardless of viral load), people living with HIV appear more vulnerable to COVID-19 and should be prioritized for vaccination.

A case of SARS-CoV-2 Omicron reinfection resulting in a significant immunity boost in a paediatric patient affected by B-cell acute lymphoblastic leukemia.

BACKGROUND: Since its emergence in November 2021, SARS-CoV-2 Omicron clade has quickly become dominant, due to its increased transmissibility and immune evasion. Different sublineages are currently circulating, which differ in mutations and deletions in regions of the SARS-CoV-2 genome implicated in the immune response. In May 2022, BA.1 and BA.2 were the most prevalent sublineages in Europe, both characterized by ability of evading natural acquired and vaccine-induced immunity and of escaping monoclonal antibodies neutralization. CASE PRESENTATION: A 5-years old male affected by B-cell acute lymphoblastic leukemia in reinduction was tested positive for SARS-CoV-2 by RT-PCR at the Bambino Gesù Children Hospital in Rome in December 2021. He experienced a mild COVID-19 manifestation, and a peak of nasopharyngeal viral load corresponding to 15.5 Ct. Whole genome sequencing identified the clade 21 K (Omicron), sublineage BA.1.1. The patient was monitored over time and tested negative for SARS-CoV-2 after 30 days. Anti-S antibodies were detected positive with modest titre (3.86 BAU/mL), while anti-N antibodies were negative. 74 days after the onset of the first infection and 23 days after the last negative test, the patient was readmitted to hospital with fever, and tested positive for SARS-CoV-2 by RT-PCR (peak of viral load corresponding to 23.3 Ct). Again, he experienced a mild COVID-19. Whole genome sequencing revealed an infection with the Omicron lineage BA.2 (21L clade). Sotrovimab administration was started at the fifth day of positivity, and RT-PCR negativity occurred 10 days later. Surveillance SARS-CoV-2 RT-PCR were persistently negative, and in May 2022, anti-N antibodies were found positive and anti-S antibodies reached titres > 5000 BAU/mL. CONCLUSIONS: By this clinical case, we showed that SARS-CoV-2 reinfection within the Omicron clade can occur and can be correlated to inadequate immune responses to primary infection. We also showed that the infection's length was shorter in the second respect to first episode, suggesting that pre-existing T cell-mediated immunity, though not preventing re-infection, might have limited the SARS-CoV-2 replication capacity. Lastly, Sotrovimab treatment retained activity against BA.2, probably accelerating the viral clearance in the second infectious episode, after which seroconversion and increase of anti-S antibodies titres were observed.

Relationship between viral load and symptoms in children infected with SARS-CoV-2.

BACKGROUND: The purpose of this study is to evaluate the association between SARS-CoV-2 viral load in respiratory secretions of infected children and signs/symptoms of COVID-19. METHODS: We reported the clinical characteristics of SARS-CoV-2-infected children during the study period. We compared viral load for several clinical variables, performed a predictive linear regression analysis to identify signs and symptoms significantly associated with viral load, and searched for discriminant viral load thresholds for symptomatic versus asymptomatic infections based on receiver-operating characteristics. RESULTS: A total of 570 patients were included. The median age was 4.75 years. Comparison of CT values by dichotomous variable showed higher viral loads in children with fever, respiratory symptoms, and previous exposure to SARS-CoV-2. The linear regression analysis confirmed a significant relationship between the CT value with these variables and with age, other symptoms, and asymptomaticity. In particular, infants with fever and SARS-CoV-2 exposure had higher viral loads. No viral load cut-offs were found to distinguish symptomatic from asymptomatic patients. CONCLUSION: Our study shows that fever, SARS-CoV-2 exposure, and respiratory symptoms are associated with higher viral load in children, especially infants, while age, presence of nonrespiratory symptoms, or absence of any symptoms are associated with lower viral load. IMPACT: Key message: the clinical variables that best predict viral load in infected children are history of previous exposure to a SARS-CoV-2-infected person and presence of fever and respiratory symptoms (higher viral load). Added value to the current literature: this is the first article to prove this point. IMPACT: SARS-CoV-2 viral load should not be used as a measure of clinical severity of COVID-19 in the pediatric population; however, lower viral load appears to be associated with asymptomatic COVID-19 in older children.

The COVID-19 wave was already here: High seroprevalence of SARS-CoV-2 antibodies among staff and students in a Cameroon University.

Background: Seroprevalence studies, to estimate the proportion of people that has been infected by SARS-CoV-2 are importance in African countries, where incidence is among the lowest in the world. Objective: This study aimed at evaluating the exposure to SARS-CoV-2 within a university setting of Cameroon. Methods: A cross-sectional study performed in December 2020 - December 2021, among students and staffs of the Evangelical University of Cameroon. COVID-19 antigen rapid detection test (RDT) was performed using Standard Q Biosensor, and one year after SARS-CoV-2 antibody-test was performed within the same population using RDT and chemiluminescence immunoassay (CLIA). Results: 106 participants were enrolled (80% students), female sex was the most represented. Positivity to SARS-CoV-2 was 0.0% based on antigen RDTs. The seroprevalence of SARSCoV- 2 antibodies was estimated at 73.6% (95% CI. 64.5-81.0) for IgG and 1.9% (95% CI. 0.2-6.8) for IgM/IgG with RDTs, and 91.9% (95% CI. 84.7-96.4) for anti-nucleocapsid with CLIA. 95.3% (101) reported having developed at least one of the known COVID-19 symptoms (cough and headache being the most common). 90.3% (28) of people who experienced at least one of these symptoms developed IgG antibodies. 40.6% (43) of participants took natural herbs, whereas 55.7% (59) took conventional drugs. The most used herb was Zingiber officinale, while the most used drugs were antibiotics. Conclusion: In this Cameroonian University community, SARS-CoV-2 seroprevalence is high, with a greater detection using advanced serological assays. This indicates a wide viral exposure, and the need to adequate control measures especially for those experiencing any related COVID-19 symptoms.

Severe viral respiratory infections in the pre-COVID era: A 5-year experience in two pediatric intensive care units in Italy.

BACKGROUND: Viral respiratory infections are one of the main causes of hospitalization in children. Even if mortality rate is low, 2% to 3% of the hospitalized children need mechanical ventilation. Risk factors for admission to the pediatric intensive care unit (PICU) are well known, while few studies have described risk factors for invasive ventilator support and prolonged hospitalization. METHODS: A retrospective study including all patients aged between 2 and 18 months with a confirmed viral respiratory infection, requiring admission to PICU from September to March between 2015 and 2019, was conducted at Bambino Gesù Children's Hospital in Rome, Italy. RESULTS: One hundred ninety patients were enrolled, with a median age of 2.7 months; 32.1% had at least one comorbidity, mainly prematurity. The most frequent isolated viruses were RSV-B, rhinovirus, and RSV-A; 38.4% needed mechanical ventilation. This subgroup of patients had lower median birth weight compared with patients not requiring mechanical ventilation (2800 g vs. 3180 g, p = 0.02); moreover, comorbidities were present in 43.8% of intubated patients and in 24.8% of patients treated with non-invasive ventilation (p = 0.006). Viral coinfection did not result to be a risk factor for mechanical support, while virus-bacteria coinfection was significantly associated with mechanical ventilation (p < 0.001). Similar risk factors were identified for prolonged hospitalization. CONCLUSIONS: Early identification of patients who could have a sudden respiratory deterioration and need of mechanical ventilation is crucial to reduce complications due to orotracheal intubation and prolonged hospitalization in PICU. Further studies are needed to define high-risk group of patients and to design targeted interventions.

Evaluation of archived drug resistance mutations in HIV-1 DNA among vertically infected adolescents under antiretroviral treatment in Cameroon: Findings during the COVID-19 pandemic.

BACKGROUND: With the success of antiretroviral therapy (ART), children born with HIV are more likely to reach adolescence. However, frequent non-adherence to ART in adolescents living with HIV (ALHIV) leads to viral replication. Notably, a viraemic infection might lead to archived drug resistance mutations (ADRMs). Hence, within the context of the COVID-19 pandemic, we aimed to compare the patterns of ADRMs in viraemic and non-viraemic vertically infected ALHIV and to assess their immunity to and diagnosis of SARS-CoV-2. METHODS: A comparative study was conducted among COVID-19-unvaccinated ALHIV receiving ART in Yaoundé-Cameroon over the period October 2021 to March 2022. Plasma HIV-RNA was measured using Abbott® m2000rt; HIV-1 genotyping was performed on buffy-coat (HIV-1 DNA) and ADRMs were interpreted using HIVdb.v9.0.1. Patterns of HIV-1 ADRMs were compared between viraemic (≥ 1.60 log10 HIV-1 RNA copies/ml) and non-viraemic (< 1.60 log10 copies/ml) individuals. SARS-CoV-2 antibodies were assessed on whole blood using Abbott Panbio COVID-19 immunoglobulin G/M (IgG/IgM) rapid test and COVID-19 polymerase chain reaction test was performed using nasopharyngeal swab samples. RESULTS: Of the 60 ALHIV [aged 17 (16-19) years, 51.6% female], median ART duration was 14 (12-16) years; 31/55 (56.3%) were exposed to nonnucleoside reverse transcriptase inhibitor (NNRTI)-based first-line ART (of whom 19/31 transitioned to dolutegravir-based ART in 2020) and 24/55 (43.6%) were on second-line ART. Forty-two out of 60 (70.0%) ALHIV were non-viraemic; 43/60 (71.6%) were successfully sequenced. Overall the ADRM rate was 62.7% (27/43), with 69.2% (9/13) viraemic and 60.0% (18/30) non-viraemic (p = 0.56). NNRTI-ADRMs were significantly higher among viraemic ALHIV (69.2% vs. 46.7%, p = 0.030). Regarding immunity, those with CD4 nadir < 350 cells/µl had significantly higher rates of ADRMs [adjusted odds ratio (aOR) = 3.20 (1.36-95.53), p = 0.03]. In relation to COVID-19 immunity, overall SARS-CoV-2 IgG seropositivity was 28.3% (17/60), whereas 0% (0/60) were seropositive to IgM; in particular, those with CD4 count nadir ≥ 350 cells/µl had higher odds of SARS-CoV-2 IgG seropositivity [OR =7.85 (2.03-30.28), p < 0.01]. No significant association was found between SARS-CoV-2 IgG seropositivity and HIV-RNA (non-viraemic, 33.3%; viraemic, 16.7%; p = 0.18). SARS-CoV-2 RNA prevalence was 4.5% (2/44). The two positive participants were with low-levels of viral load (Ct > 30) and seropositive to IgG. CONCLUSION: In the context of virological success, the majority of ALHIV harbour ADRMs, essentially driven by NNRTI mutations and low CD4 nadir. During the current pandemic, about one-third of ALHIV were previously exposed to SARS-CoV-2. However, some children might have been exposed and uninfected and others might have been infected but showed no serological response at sampling. These findings support the use of NNRTI-sparing regimens and the implementation of COVID-19 barrier measures targeting ALHIV during such a pandemic.

A proof-of-concept study on the genomic evolution of Sars-Cov-2 in molnupiravir-treated, paxlovid-treated and drug-naïve patients.

Little is known about SARS-CoV-2 evolution under Molnupiravir and Paxlovid, the only antivirals approved for COVID-19 treatment. By investigating SARS-CoV-2 variability in 8 Molnupiravir-treated, 7 Paxlovid-treated and 5 drug-naïve individuals at 4 time-points (Days 0-2-5-7), a higher genetic distance is found under Molnupiravir pressure compared to Paxlovid and no-drug pressure (nucleotide-substitutions/site mean±Standard error: 18.7 × 10-4 ± 2.1 × 10-4 vs. 3.3 × 10-4 ± 0.8 × 10-4 vs. 3.1 × 10-4 ± 0.8 × 10-4, P = 0.0003), peaking between Day 2 and 5. Molnupiravir drives the emergence of more G-A and C-T transitions than other mutations (P = 0.031). SARS-CoV-2 selective evolution under Molnupiravir pressure does not differ from that under Paxlovid or no-drug pressure, except for orf8 (dN > dS, P = 0.001); few amino acid mutations are enriched at specific sites. No RNA-dependent RNA polymerase (RdRp) or main proteases (Mpro) mutations conferring resistance to Molnupiravir or Paxlovid are found. This proof-of-concept study defines the SARS-CoV-2 within-host evolution during antiviral treatment, confirming higher in vivo variability induced by Molnupiravir compared to Paxlovid and drug-naive, albeit not resulting in apparent mutation selection.

The Relationship Between Pediatric Gut Microbiota and SARS-CoV-2 Infection.

This is the first study on gut microbiota (GM) in children affected by coronavirus disease 2019 (COVID-19). Stool samples from 88 patients with suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and 95 healthy subjects were collected (admission: 3-7 days, discharge) to study GM profile by 16S rRNA gene sequencing and relationship to disease severity. The study group was divided in COVID-19 (68), Non-COVID-19 (16), and MIS-C (multisystem inflammatory syndrome in children) (4). Correlations among GM ecology, predicted functions, multiple machine learning (ML) models, and inflammatory response were provided for COVID-19 and Non-COVID-19 cohorts. The GM of COVID-19 cohort resulted as dysbiotic, with the lowest α-diversity compared with Non-COVID-19 and CTRLs and by a specific ß-diversity. Its profile appeared enriched in Faecalibacterium, Fusobacterium, and Neisseria and reduced in Bifidobacterium, Blautia, Ruminococcus, Collinsella, Coprococcus, Eggerthella, and Akkermansia, compared with CTRLs (p < 0.05). All GM paired-comparisons disclosed comparable results through all time points. The comparison between COVID-19 and Non-COVID-19 cohorts highlighted a reduction of Abiotrophia in the COVID-19 cohort (p < 0.05). The GM of MIS-C cohort was characterized by an increase of Veillonella, Clostridium, Dialister, Ruminococcus, and Streptococcus and a decrease of Bifidobacterium, Blautia, Granulicatella, and Prevotella, compared with CTRLs. Stratifying for disease severity, the GM associated to "moderate" COVID-19 was characterized by lower α-diversity compared with "mild" and "asymptomatic" and by a GM profile deprived in Neisseria, Lachnospira, Streptococcus, and Prevotella and enriched in Dialister, Acidaminococcus, Oscillospora, Ruminococcus, Clostridium, Alistipes, and Bacteroides. The ML models identified Staphylococcus, Anaerostipes, Faecalibacterium, Dorea, Dialister, Streptococcus, Roseburia, Haemophilus, Granulicatella, Gemmiger, Lachnospira, Corynebacterium, Prevotella, Bilophila, Phascolarctobacterium, Oscillospira, and Veillonella as microbial markers of COVID-19. The KEGG ortholog (KO)-based prediction of GM functional profile highlighted 28 and 39 KO-associated pathways to COVID-19 and CTRLs, respectively. Finally, Bacteroides and Sutterella correlated with proinflammatory cytokines regardless disease severity. Unlike adult GM profiles, Faecalibacterium was a specific marker of pediatric COVID-19 GM. The durable modification of patients' GM profile suggested a prompt GM quenching response to SARS-CoV-2 infection since the first symptoms. Faecalibacterium and reduced fatty acid and amino acid degradation were proposed as specific COVID-19 disease traits, possibly associated to restrained severity of SARS-CoV-2-infected children. Altogether, this evidence provides a characterization of the pediatric COVID-19-related GM.

Performance evaluation of a new on-demand molecular test for the rapid identification of severe acute respiratory syndrome coronavirus 2 in pediatric and adult patients.

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has increased the need to identify additional rapid diagnostic tests for an accurate and early diagnosis of infection. Here, we evaluated the diagnostic performance of the cartridge-based reverse transcription polymerase chain reaction (RT-PCR) test STANDARD M10 SARS-CoV-2 (SD Biosensor Inc., Suwon, South Korea), targeting the ORF1ab and E gene of SARS-CoV-2, and which can process up to eight samples in parallel in 60 min. From January 2022 to March 2022, STANDARD™ M10 assay performance was compared with Xpert® Xpress SARS-CoV-2 (Cepheid, Sunnyvale CA) on 616 nasopharyngeal swabs from consecutive pediatric (N = 533) and adult (N = 83) patients presenting at the "Istituto di Ricovero e Cura a Carattere Scientifico" (IRCCS) Ospedale Pediatrico Bambino Gesù, Roma. The overall performance of STANDARD M10 SARS-CoV-2 was remarkably and consistently comparable to the Xpert® Xpress SARS-CoV-2 with an overall agreement of 98% (604/616 concordant results), and negligible differences in time-to-result (60 min vs. 50 min, respectively). When the Xpert® Xpress SARS-CoV-2 results were considered as the reference, STANDARD™ M10 SARS-CoV-2 had 96.5% sensitivity and 98.4% specificity. STANDARD M10 SARS-CoV-2 can thus be safely included in diagnostic pathways because it rapidly and accurately identifies SARS-CoV-2 present in nasopharyngeal swabs.

Global burden of SARS-CoV-2 infection, hospitalization and case fatality rate among COVID-19 vaccinated individuals and its associated factors: A systematic review and meta-analysis protocol.

BACKGROUND: COVID-19 has been the most important public health concern worldwide since 2020. Several vaccines are now available to help in controlling COVID-19 associated morbidity and mortality. This study will aim to provide the global and regional prevalence of SARS-CoV-2 infection as well as an estimate of disease severity among COVID-19 vaccinated individuals. MATERIALS AND METHODS: In order to determine the global burden of SARS-CoV-2 infection among vaccinated individuals, we will systematically extract and review papers from PubMed/MEDLINE, Excerpta Medica database (EMBASE), Cochrane Central Register of Controlled Trials (CENTRAL), Science direct and Cumulative Index to Nursing and Allied Health Literature (CINAHL). All the studies describing the prevalence and/or disease severity (hospitalization and case fatality rate) data of COVID-19 among individuals who received a partial or complete dose of WHO-approved COVID-19 vaccines will be eligible. A random effect model will be used to calculate the pooled prevalence and to estimate the disease severity. Subgroup analysis will be performed to explore the association between the number of vaccine doses received and the COVID-19 burdens. DISCUSSION: This systematic review and meta-analysis will provide the global estimate data on pooled prevalence, hospitalization and case fatality rates of COVID-19 among vaccinated individuals. Moreover, the factors associated with reinfection and disease severity will be equally investigated in the meta-analysis. The results of this study will contribute in the understanding and estimation of the global burden of COVID-19 among vaccinated individuals. Findings will provide meaningful information for the success of the current global rollout of COVID-19 vaccination strategies and pave the way for future interventions. SYSTEMATIC REVIEW REGISTRATION: CRD42021273074.

Case report: Microcirculatory leukocytes in a pediatric patient with severe SARS-CoV-2 pneumonia. Findings of leukocytes trafficking beyond the lungs

Background SARS-CoV-2 can lead to excessive coagulation and thrombo-inflammation with deposition of microthrombi and microvascular dysfunction. Several studies in human and animal models have already evidenced biomarkers of endothelial injury during SARS-CoV-2 infection. Real-time observation of sublingual microcirculation using an handheld vital microscopy with an Incident Dark Field (IDF) technique could represent a non-invasive way to assess early signs of microvascular dysfunction and endothelial inflammation in patients with severe COVID-19 infection. Clinical case We report for the first time in a pediatric patient with severe SARS-CoV-2 pneumonia findings about microcirculatory leukocytes in the sublingual microcirculation of a 7 month-old patient admitted to our PICU using handheld vital microscopy with IDF technique. Results Sublingual microcirculation analysis revealed the presence of microcirculatory alterations and an extensive presence of leukocytes in the patient’s sublingual microcirculation. It’s significant to underline how the patient didn’t show a contextual significant increase in inflammatory biomarkers or other clinical signs related to an inflammatory response, beyond the presence of severe hypoxic respiratory failure. Conclusion Leukocyte activation in multiple organs can occur at the endothelial lining of the microvasculature where a surge of pro-inflammatory mediators can result in accumulation of activated leukocytes and degradation of the endothelium. The introduction of a method to assess in a non-invasive, real-time manner the extent of inflammation in a patient with COVID19 could lead to potential clinical and therapeutic implications. However, more studies are required to prove that studying leukocytes microcirculation using sublingual microcirculation analysis could be useful as a bedside point of care monitor to predict the presence of systemic inflammation associated with the impact of COVID-19, leading in a late phase of severe SARS-CoV-2 infection to a microvascular dysfunction and micro-thrombosis.

Lessons from SARS-CoV-2 Pandemics: How Restrictive Measures Impacted the Trend of Respiratory Infections in Neonates and Infants up to Three Months of Age.

(1) Background: Massive social efforts to prevent the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic have affected the epidemiological features of respiratory infections. (2) Methods: The study aims to describe the trend of hospitalizations for bronchiolitis among newborns and infants up to three months of life in Rome (Italy), in the pre-COVID-19 era and during the pandemic. (3) Results: We observed a marked decrease in the number of neonates and infants with bronchiolitis after national lockdowns in 2020 and the first months of 2021 and a similar trend in the number of bronchiolitis caused by respiratory syncytial virus (RSV). RSV was the leading pathogen responsible for bronchiolitis before the national lockdown in March 2020 (70.0% of cases), while Rhinovirus was the leading pathogen responsible for bronchiolitis (62.5%) during the pandemic while strict restrictions were ongoing. As Italy approached the COVID-19 vaccination target, the national government lifted some COVID-19-related restrictions. A surprising rebound of bronchiolitis (particularly cases caused by RSV) was observed in October 2021. (4) Conclusions: In this study, we describe for the first time the fluctuations over time of RSV bronchiolitis among newborns and young infants in Italy in relation to the restrictive measures containing the spread of the COVID-19 pandemic. Our results are in line with other countries' reports.

Diagnostic performance of molecular and serological tests of SARS-CoV-2 on well-characterised specimens from COVID-19 individuals: The EDCTP "PERFECT-study" protocol (RIA2020EF-3000).

BACKGROUND: The SARS-CoV-2 pandemic is a global threat affecting 210 countries, with 2,177,469 confirmed cases and 6.67% case fatality rate as of April 16, 2020. In Africa, 17,243 cases have been confirmed, but many remain undiagnosed due to limited laboratory-capacity, suboptimal performance of used molecular-assays (~30% false negative, Yu et al. and Zhao et al., 2020) and limited WHO-recommended rapid-tests. OBJECTIVES: We aim to implement measures to minimize risks for COVID-19 in Cameroon, putting together multidisciplinary highly-experienced virologists, immunologists, bioinformaticians and clinicians, to achieve the following objectives: (a) to integrate/improve available-infrastructure, methodologies, and expertise on COVID-19. For this purpose, we will create a platform enabling researchers/clinicians to better integrate and translate evidence into the COVID-19 clinical-practice; (b) to enhance capacities in Cameroon for screening/detecting individuals with high-risks of COVID-19, by setting-up effective core-facilities on-site; (c) to validate point-of-care SARS-CoV-2 molecular assays allowing same-day result delivery, thus permitting timely diagnosis, treatment, and retention in care of COVID-19 patients; (d) to implement SARS-CoV-2 diagnosis with innovative/highly sensitive ddPCR-based assays and viral genetic characterization; (e) to validate serological assays to identify COVID-19-exposed persons and follow-up of convalescents. METHODS: This is a prospective, observational study conducted among COVID-19 suspects/contacts during 24 months in Cameroon. Following consecutive sampling of 1,536 individuals, oro/nasopharyngeal swabs and sera will be collected. Well characterised biorepositories will be established locally; molecular testing will be performed on conventional real-time qPCR, point-of-care GeneXpert, antigen-tests and digital droplet PCR (ddPCR); SARS-CoV2 amplicons will be sequenced; serological testing will be performed using ELISA, and antibody-based kits. Sensitivity, specificity, positive- and negative-predictive values will be evaluated. EXPECTED OUTCOMES: These efforts will contribute in creating the technical and clinical environment to facilitate earlier detection of Sars-CoV-2 in Africa in general and in Cameroon in particular. Specifically, the goals will be: (a) to implement technology transfer for capacity-building on conventional and point-of-care molecular assays, achieving a desirable performance for clinical diagnosis of SARS-CoV2; (b) to integrate/improve the available infrastructure, methodologies, and expertise on Sars-CoV2 detection; (c) to improve the turn-around-time for diagnosing COVID-19 infection with obvious advantage for patients/clinical management thanks to low-cost assays, thus permitting timely treatment and retention in care; (d) to assess the epidemiology of COVID-19 and circulating-variants in Cameroon as compared to strains found in other countries.

Perinatally Human Immunodeficiency Virus-Infected Adolescents and Young Adults Demonstrate Distinct BNT162b2 Messenger RNA Coronavirus Disease 2019 Vaccine Immunogenicity.

BACKGROUND: Immunization of vulnerable populations with distinct immunity often results in suboptimal immunogenicity, durability, and efficacy. METHODS: Safety and immunogenicity profiles of BNT162b2 messenger RNA coronavirus disease 2019 (COVID-19) vaccine, among people living with human immunodeficiency virus (HIV), were evaluated in 28 perinatally HIV-infected patients under antiretroviral therapy (ART) and 65 healthy controls (HCs) with no previous history of COVID-19. Thus, we measured severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific humoral and CD4+ T cell responses. Samples were collected before vaccination (baseline, day [D] 0), at the second dose (D21), and at 4 weeks (D28) and 6 months (D180) after D0. Proteomic profiles at D0 and D28 were assessed with a multiplexed proximity extension assay (Olink) on plasma samples. RESULTS: All HIV-infected patients mounted similar anti-SARS-CoV-2 humoral responses to those of HCs, albeit with lower titers of anti-trimeric S at D28 (P = .01). Only peripheral blood mononuclear cells of HIV-infected patients demonstrated at D28 an impaired ability to expand their specific (CD40L+) CD4+ T-cell populations. Similar humoral titers were maintained between the 2 groups at 6-months follow-up. We additionally correlated baseline protein levels to either humoral or cellular responses, identifying clusters of molecules involved in immune response regulation with inverse profiles between the 2 study groups. CONCLUSIONS: Responses of ART-treated HIV-infected patients, compared to those of HCs, were characterized by distinct features especially within the proteomic compartment, supporting their eligibility to an additional dose, similarly to the HC schedule.

Epidemiological characterization of SARS-CoV-2 variants in children over the four COVID-19 waves and correlation with clinical presentation.

Since the start of SARS-CoV-2 pandemic, children aged ≤ 12 years have always been defined as underrepresented in terms of SARS-CoV-2 infections' frequency and severity. By correlating SARS-CoV-2 transmission dynamics with clinical and virological features in 612 SARS-CoV-2 positive patients aged ≤ 12 years, we demonstrated a sizeable circulation of different SARS-CoV-2 lineages over the four pandemic waves in paediatric population, sustained by local transmission chains. Age < 5 years, highest viral load, gamma and delta clades positively influence this local transmission. No correlations between COVID-19 manifestations and lineages or transmission chains are seen, except for a negative correlation between B.1.1.7 and hospitalization.

The Relationship Between Pediatric Gut Microbiota and SARS-CoV-2 Infection

This is the first study on gut microbiota (GM) in children affected by coronavirus disease 2019 (COVID-19). Stool samples from 88 patients with suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and 95 healthy subjects were collected (admission: 3–7 days, discharge) to study GM profile by 16S rRNA gene sequencing and relationship to disease severity. The study group was divided in COVID-19 (68), Non–COVID-19 (16), and MIS-C (multisystem inflammatory syndrome in children) (4). Correlations among GM ecology, predicted functions, multiple machine learning (ML) models, and inflammatory response were provided for COVID-19 and Non–COVID-19 cohorts. The GM of COVID-19 cohort resulted as dysbiotic, with the lowest α-diversity compared with Non–COVID-19 and CTRLs and by a specific β-diversity. Its profile appeared enriched in Faecalibacterium, Fusobacterium, and Neisseria and reduced in Bifidobacterium, Blautia, Ruminococcus, Collinsella, Coprococcus, Eggerthella, and Akkermansia, compared with CTRLs (p < 0.05). All GM paired-comparisons disclosed comparable results through all time points. The comparison between COVID-19 and Non–COVID-19 cohorts highlighted a reduction of Abiotrophia in the COVID-19 cohort (p < 0.05). The GM of MIS-C cohort was characterized by an increase of Veillonella, Clostridium, Dialister, Ruminococcus, and Streptococcus and a decrease of Bifidobacterium, Blautia, Granulicatella, and Prevotella, compared with CTRLs. Stratifying for disease severity, the GM associated to “moderate” COVID-19 was characterized by lower α-diversity compared with “mild” and “asymptomatic” and by a GM profile deprived in Neisseria, Lachnospira, Streptococcus, and Prevotella and enriched in Dialister, Acidaminococcus, Oscillospora, Ruminococcus, Clostridium, Alistipes, and Bacteroides. The ML models identified Staphylococcus, Anaerostipes, Faecalibacterium, Dorea, Dialister, Streptococcus, Roseburia, Haemophilus, Granulicatella, Gemmiger, Lachnospira, Corynebacterium, Prevotella, Bilophila, Phascolarctobacterium, Oscillospira, and Veillonella as microbial markers of COVID-19. The KEGG ortholog (KO)–based prediction of GM functional profile highlighted 28 and 39 KO-associated pathways to COVID-19 and CTRLs, respectively. Finally, Bacteroides and Sutterella correlated with proinflammatory cytokines regardless disease severity. Unlike adult GM profiles, Faecalibacterium was a specific marker of pediatric COVID-19 GM. The durable modification of patients’ GM profile suggested a prompt GM quenching response to SARS-CoV-2 infection since the first symptoms. Faecalibacterium and reduced fatty acid and amino acid degradation were proposed as specific COVID-19 disease traits, possibly associated to restrained severity of SARS-CoV-2–infected children. Altogether, this evidence provides a characterization of the pediatric COVID-19–related GM.