A systematic review on the levels of antibodies in COVID-19 virus exposed but negative newborns: a possible vertical transmission of IgG/ IgM

BackgroundCurrently, there is no doubt on human-to-human transmission of Coronavirus Disease 2019 (COVID-19). Now, the debates remain on whether, vertical transmission of Severe Respiratory Syndrome Virus 2 (SARS-CoV-2) and antibodies against the virus do exist. We therefore, conducted a systematic review to determine the immunoglobulin G and M (IgG/IgM) levels among infants born to mothers with COVID-19. MethodsThe systematic search was done using PubMed/MEDLINE and Google Scholar database. The research included studies on IgG/ IgM against SARS-CoV-2 among infants born to mother with COVID-19 published in English from December 1, 2019 onwards. Data were extracted by two independent authors in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-P) guidelines. We synthesized a narrative from eligible studies and performed two tailed non-parametric Mann-Whitney test to determine and compare the median IgG/IgM levels. ResultsIn total, 486 abstracts were screened and 63 full-text articles were assessed. Of 63 articles, 6 met the inclusion criteria for qualitative analysis. Two articles were included in quantitative analysis of anti-SARS-CoV-2 IgG/ IgM levels. The median antibody levels was 75.49AU/mL (range: 7.25AU/mL-140.32AU/mL) and for 3.79AU/mL (range: 0.16AU/mL-45.83AU/mL) (P = 0.0041) for anti-SARS-CoV-2 IgG and IgM, respectively. ConclusionThere were high levels of IgG but low IgM against SARS-CoV-2 (using <10 AU/mL as a reference range) among COVID-19 virus exposed but negative newborns. This review suggest a possible natural passive immunity (IgG/ IgM) against COVID-19 virus. ImpactA systematic review of infants born to mothers with COVID-19 was conducted to characterize the magnitude of antibodies generated against SARS-CoV-2 among infants who were vertically exposed to the virus. These findings were necessary to inform the ongoing vaccine development and research on the background natural passive immunity among COVID-19 exposed newborns. Furthermore, evidence are revealing the possibility of vertical transmission of anti-SARS-CoV-2 IgG/ IgM among the exposed newborns who tested negative for the virus.