Immune profiling of SARS-CoV-2 epitopes in asymptomatic and symptomatic pediatric and adult patients.

BACKGROUND: The infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unpredictable manifestations of coronavirus disease (COVID-19) and variable clinical course with some patients being asymptomatic whereas others experiencing severe respiratory distress, or even death. We aimed to evaluate the immunoglobulin G (IgG) response towards linear peptides on a peptide array containing sequences from SARS-CoV-2, Middle East respiratory syndrome-related coronavirus (MERS) and common-cold coronaviruses 229E, OC43, NL63 and HKU1 antigens, in order to identify immunological indicators of disease outcome in SARS-CoV-2 infected patients. METHODS: We included in the study 79 subjects, comprising 19 pediatric and 30 adult SARS-CoV-2 infected patients with increasing disease severity, from mild to critical illness, and 30 uninfected subjects who were vaccinated with one dose of SARS-CoV-2 spike mRNA BNT162b2 vaccine. Serum samples were analyzed by a peptide microarray containing 5828 overlapping 15-mer synthetic peptides corresponding to the full SARS-CoV-2 proteome and selected linear epitopes of spike (S), envelope (E) and membrane (M) glycoproteins as well as nucleoprotein (N) of MERS, SARS and coronaviruses 229E, OC43, NL63 and HKU1 (isolates 1, 2 and 5). RESULTS: All patients exhibited high IgG reactivity against the central region and C-terminus peptides of both SARS-CoV-2 N and S proteins. Setting the threshold value for serum reactivity above 25,000 units, 100% and 81% of patients with severe disease, 36% and 29% of subjects with mild symptoms, and 8% and 17% of children younger than 8-years reacted against N and S proteins, respectively. Overall, the total number of peptides in the SARS-CoV-2 proteome targeted by serum samples was much higher in children compared to adults. Notably, we revealed a differential antibody response to SARS-CoV-2 peptides of M protein between adults, mainly reacting against the C-terminus epitopes, and children, who were highly responsive to the N-terminus of M protein. In addition, IgG signals against NS7B, NS8 and ORF10 peptides were found elevated mainly among adults with mild (63%) symptoms. Antibodies towards S and N proteins of other coronaviruses (MERS, 229E, OC43, NL63 and HKU1) were detected in all groups without a significant correlation with SARS-CoV-2 antibody levels. CONCLUSIONS: Overall, our results showed that antibodies elicited by specific linear epitopes of SARS-CoV-2 proteome are age dependent and related to COVID-19 clinical severity. Cross-reaction of antibodies to epitopes of other human coronaviruses was evident in all patients with distinct profiles between children and adult patients. Several SARS-CoV-2 peptides identified in this study are of particular interest for the development of vaccines and diagnostic tests to predict the clinical outcome of SARS-CoV-2 infection.

Changing Epidemiology of Acute Viral Respiratory Infections in Hospitalized Children: The Post-Lockdown Effect.

Several reports highlighted how public health measures aimed at limiting severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) circulation have likely contributed to reducing the circulation of other respiratory viruses, particularly during the first year of the COVID-19 pandemic. We evaluated the epidemiology of acute respiratory infections in a large cohort of hospitalized children during the third year of the pandemic (2021−2022). We retrospectively analyzed data from the health records of children (<14 years) hospitalized for acute respiratory infections between 1 July 2021 and 31 March 2022. A total of 1763 respiratory panels were collected. Overall, 1269 (72%) panels hadpositive results for at least one pathogen. Most positive panels (53.8%) belonged to patients aged 1−12 months. The most detected pathogen was respiratory syncytial virus (RSV) (57.8% of positive panels). The RSV peak occurred in November 2021. Nine hundred and forty-five (74.5%) panels were positive for one pathogen while three hundred and twenty-four (25.5%) showed multiple infections. Patients with multiple infections were significantly older than those with a single infection. The 2021−2022 peak of RSV infection in Italy occurred earlier than in the previous pre-pandemic seasons. A high number of children have been hospitalized because of acute viral infections also due to less aggressive viruses.

Detection of SARS-CoV-2 infection in a pediatric population from south Italy without symptoms of Coronavirus Disease 2019.

BACKGROUND: SARS-CoV-2 has had dramatic consequences on the world population in morbidity and mortality and socially. Clinical manifestations range from common cold-like to more severe disease such as bronchitis, pneumonia, severe acute respiratory distress syndrome, multi-organ failure and even death. The pediatric population may be infected with SARS-CoV-2, but is less likely to be symptomatic or develop severe symptoms. METHODS: We analyzed a cohort of pediatric subjects from Campania Region, south Italy, without symptoms of SARS-CoV2, to evaluate the distribution of infection in relation to gender and age. Detection on nasopharyngeal swabs was performed with two different RT-PCR methods, a qualitative rapid test (VitaPCRTM SARS-CoV-2 assay) and a quantitative test (SARS-CoV-2 ELITe MGB® assay). RESULTS: Positive subjects were 52.63% male and 47.36% female. Regarding age distribution, we described a consistent increase of detection rate (82.45%) in 0-2 year-old patients. CONCLUSION: The importance of children in transmitting the virus remains uncertain; however our analysis of the distribution of the infection in these subjects may help monitor SARS-CoV2 spread in the general population.

Detection of Human Papillomaviruses in the Nasopharynx of Breastfed Infants: New Findings and Meta-Analysis.

Vertical transmission of human papillomaviruses (HPVs) from mother to infant is known to occur during labor, delivery or breastfeeding. Infection with mucosal HPV 6 and 11 may cause recurrent respiratory papillomatosis in children, which is a rare and severe respiratory disease. The cutaneous HPV genotypes have also been described to be transmitted from mother to newborn through skin-to-skin contacts and during breastfeeding. To investigate the perinatal transmission of alpha and beta HPVs we collected nasopharyngeal specimens from 0-12-months-old infants born by vaginal delivery and breastfed at the time of sample collection. The mucosal and cutaneous HPVs were searched by nested PCR using the MY09/11-MGPs and CP65/70-CP66/69 primer sets, respectively, and genotypes identified by direct sequencing analysis. Fourteen out of 113 (12.4%) samples tested positive for HPV and sequence analysis allowed us to identify eight beta genotypes (HPV 5b, 20, 25, 100, 107, 124, 152 and RTRX7). Moreover, we performed a comprehensive review of published studies on the prevalence of mucosal and cutaneous HPVs among 5126 newborns and observed that 10% and 53% were positive for alpha and beta HPVs, respectively. In all studies there was an inverse correlation between the rate of alpha HPV positivity and age, while a significant positive trend was observed in beta HPV detection and age with the highest rate among children older than 12 months (Χ2 test for trend of 10.6, p < 0.001). Further studies are needed to confirm the hypothesis that beta HPVs are transmitted to breastfeeding infants through shedding of viruses in the breast milk or on the external breast epithelium.

Characterization of respiratory infection viruses in hospitalized children from Naples province in Southern Italy.

Most acute respiratory infections (ARIs) in children are due to viral etiology, and represent an important cause of mortality and morbidity in children <5 years old in developing countries. The pathogens that cause ARIs vary geographically and by season, and viruses serve a major role. In the present study, the distribution of the seven respiratory viruses that are more prevalent in Southern European countries were retrospectively analyzed in a Southern Italy Hospital, that centralizes pediatric diseases from the Naples province. Viruses were categorized by a FilmArray Respiratory Panel, and demonstrated no substantial differences in sex, age and seasonal viruses distribution. However, all the investigated viruses had a higher detection rate in the surrounding municipalities than in the metropolitan area of Naples. In recent years, the association between air pollution and respiratory infections has become an increasing public health concern. The data in this study support this association in the surrounding areas of Naples extensively contaminated by environmental toxic agents. In these areas, characterization of the epidemiology of ARIs is required to implement a prevention and control program.