Investigation of the Passage of Antiviral Antibodies From Mother to Child

Infections remain a major cause of neonatal morbidity and mortality worldwide. At birth, multiple microorganisms, to which they are particularly vulnerable given the immaturity and naïve nature of their immune system, may infect newborns. Passive immunity by transplacental transfer of maternal antibodies is therefore of major importance in the first weeks and months of life before their own vaccination or until this period of immunological vulnerability has passed. Some factors are known to affect transplacental passage of antibodies but these have generally been studied in small series and many other parameters have not yet been investigated. The transmission rate of antibodies, particularly neutralizing antibodies, remains little explored, as well as the difference in transfer between antibodies induced by vaccination and those induced by natural infection, or the influence of maternal factors such as multiple pregnancy, other infections and treatment of these infections. A better identification and understanding of the factors that can affect transplacental transfer of maternal antibodies is crucial for optimization of vaccination strategies and close monitoring of particularly vulnerable newborns.