The Role of Maternally Acquired Antibody in Providing Protective Immunity Against Nontyphoidal Salmonella in Urban Vietnamese Infants: A Birth Cohort Study

Ruklanthi De Alwis, Le Thi Phuong Tu, Nhi Le Thi Quynh, Corinne N. Thompson, Katherine L. Anders, Nguyen Thi Van Thuy, Nguyen Trong Hieu, Lu Lan Vi, Nguyen Van Vinh Chau, Vu Thuy Duong, Tran Thi Hong Chau, Ha Thanh Tuyen, Tran Vu Thieu Nga, Pham Van Minh, Trinh Van Tan, Trang Nguyen Hoang Thu, Tran Do Hoang Nhu, Guy E. Thwaites, Cameron Simmons, Stephen Baker

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Background Nontyphoidal Salmonella (NTS) organisms are a major cause of gastroenteritis and bacteremia, but little is known about maternally acquired immunity and natural exposure in infant populations residing in areas where NTS disease is highly endemic. Methods We recruited 503 pregnant mothers and their infants (following delivery) from urban areas in Vietnam and followed infants until they were 1 year old. Exposure to the dominant NTS serovars, Salmonella enterica serovars Typhimurium and Enteritidis, were assessed using lipopolysaccharide (LPS) O antigen-specific antibodies. Antibody dynamics, the role of maternally acquired antibodies, and NTS seroincidence rates were modeled using multivariate linear risk factor models and generalized additive mixed-effect models. Results Transplacental transfer of NTS LPS-specific maternal antibodies to infants was highly efficient. Waning of transplacentally acquired NTS LPS-specific antibodies at 4 months of age left infants susceptible to Salmonella organisms, after which they began to seroconvert. High seroincidences of S. Typhimurium and S. Enteritidis LPS were observed, and infants born with higher anti-LPS titers had greater plasma bactericidal activity and longer protection from seroconversion. Conclusions Although Vietnamese infants have extensive exposure to NTS, maternally acquired antibodies appear to play a protective role against NTS infections during early infancy. These findings suggest that prenatal immunization may be an appropriate strategy to protect vulnerable infants from NTS disease.

Original languageEnglish
Pages (from-to)295-304
Number of pages10
JournalJournal of Infectious Diseases
Issue number2
Publication statusPublished - 7 Jan 2019


  • infant antibodies
  • maternal antibodies
  • maternal immunization
  • Nontyphoidal Salmonella
  • NTS
  • Salmonella Enteritidis
  • Salmonella Typhimurium
  • seroepidemiology
  • seroincidence
  • transplacentally acquired immunity
  • Vietnam

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