{"title":"Pre-pandemic antibodies screening against SARS-CoV-2 and virus detection among children diagnosed with eruptive fevers.","authors":"Nouhaila Najimi, Latifa Tajount, Zakia Regragui, Chaimae Remz, Rokaya Ait-Lhaj-Mhand, Chaimae Kadi, Lamiae Belayachi, Fouad Seghrouchni, Nadia Dakka, Rabii Ameziane El Hassani, Elmir Elharti, Hicham Oumzil, Youssef Bakri","doi":"10.1177/03946320241260633","DOIUrl":null,"url":null,"abstract":"<p><strong>Objectives: </strong>This study aims to assess the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies against the spike (S) and nucleocapsid (NP) proteins, as well as neutralizing antibodies against the receptor-binding domain (RBD). Additionally, it aims to detect viral RNA of SARS-CoV-2 in pre-pandemic archival pediatric specimens collected before the announcement of the COVID-19 pandemic spread on March 20<sup>th</sup>, 2020, in Morocco. The objective is to investigate the existence of pre-pandemic immunity to SARS-CoV-2.</p><p><strong>Methods: </strong>We conducted a cross-sectional study, to analyze IgG antibody levels in a cohort of 106 pre-pandemic pediatric participants. Using an indirect enzyme-linked immunosorbent assay (ELISA), we measured the IgG levels against the S and NP proteins of SARS-CoV-2. Additionally, we staged a competitive ELISA assay to evaluate the neutralizing capability of these antibodies. We used reverse transcription polymerase chain reaction (rRT-PCR) to detect viral NP and ORF1ab genes of SARS-CoV-2 in oropharyngeal swabs. Moreover, we conducted on the same specimens a multiplexed RT-PCR to detect RNA of the most common 27 pathogens involved in lower respiratory tract infections.</p><p><strong>Results: </strong>Among the 106 serum samples, 13% (<i>n</i>n = =14) tested positive for SARS-CoV-2 IgG antibodies using ELISA. Temporal analysis indicated varying IgG positivity levels across 2019. Neutralizing antibodies were found in 21% of the 28 samples analyzed, including two with high inhibition rates (93%). The SARS-CoV-2 RNA was detected using rRT-PCR in 14 samples. None of the samples tested positive for the other 27 pathogens associated with lower respiratory tract infections, using multiplexed RT-PCR.</p><p><strong>Conclusion: </strong>Our study addresses the possibility, that COVID-19 infections occurred in Morocco before the recognized outbreak. On the other hand, some of the cases might reflect cross-reactivity with other coronaviruses or be influenced by previous viral exposures or vaccinations. Understanding these factors is crucial to comprehending pediatric immune responses to newly emerging infectious diseases.</p>","PeriodicalId":48647,"journal":{"name":"International Journal of Immunopathology and Pharmacology","volume":"38 ","pages":"3946320241260633"},"PeriodicalIF":3.5000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11155355/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Immunopathology and Pharmacology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/03946320241260633","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives: This study aims to assess the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies against the spike (S) and nucleocapsid (NP) proteins, as well as neutralizing antibodies against the receptor-binding domain (RBD). Additionally, it aims to detect viral RNA of SARS-CoV-2 in pre-pandemic archival pediatric specimens collected before the announcement of the COVID-19 pandemic spread on March 20th, 2020, in Morocco. The objective is to investigate the existence of pre-pandemic immunity to SARS-CoV-2.
Methods: We conducted a cross-sectional study, to analyze IgG antibody levels in a cohort of 106 pre-pandemic pediatric participants. Using an indirect enzyme-linked immunosorbent assay (ELISA), we measured the IgG levels against the S and NP proteins of SARS-CoV-2. Additionally, we staged a competitive ELISA assay to evaluate the neutralizing capability of these antibodies. We used reverse transcription polymerase chain reaction (rRT-PCR) to detect viral NP and ORF1ab genes of SARS-CoV-2 in oropharyngeal swabs. Moreover, we conducted on the same specimens a multiplexed RT-PCR to detect RNA of the most common 27 pathogens involved in lower respiratory tract infections.
Results: Among the 106 serum samples, 13% (nn = =14) tested positive for SARS-CoV-2 IgG antibodies using ELISA. Temporal analysis indicated varying IgG positivity levels across 2019. Neutralizing antibodies were found in 21% of the 28 samples analyzed, including two with high inhibition rates (93%). The SARS-CoV-2 RNA was detected using rRT-PCR in 14 samples. None of the samples tested positive for the other 27 pathogens associated with lower respiratory tract infections, using multiplexed RT-PCR.
Conclusion: Our study addresses the possibility, that COVID-19 infections occurred in Morocco before the recognized outbreak. On the other hand, some of the cases might reflect cross-reactivity with other coronaviruses or be influenced by previous viral exposures or vaccinations. Understanding these factors is crucial to comprehending pediatric immune responses to newly emerging infectious diseases.
期刊介绍：
International Journal of Immunopathology and Pharmacology is an Open Access peer-reviewed journal publishing original papers describing research in the fields of immunology, pathology and pharmacology. The intention is that the journal should reflect both the experimental and clinical aspects of immunology as well as advances in the understanding of the pathology and pharmacology of the immune system.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
