Ready to Benefit From Training: Heterologous Effects of Early Life Immunization

Trans R Soc Trop Med Hyg. 2015 Jan;109(1):3-4. doi: 10.1093/trstmh/tru185.


Trained immunity reflects the ability of the innate immune system to adapt via epigenetic changes in monocytes, enhancing responses to a range of microbes, thereby potentially reducing infection in high-risk populations. Examples of trained immunity at birth include enhanced resistance to infection in TLR-simulated newborn mice, reduced risk of late onset sepsis with histologic chorioamnionitis and beneficial heterologous effects of neonatal bacille Calmette-Guérin administration in reducing diverse infections during infancy. Future efforts will assess leveraging trained immunity in early life by administering 'stand-alone' innate immune stimuli or (self-)adjuvanted vaccines to protect against a broad range of infections.

Keywords: Heterologous immunity; Infant; Newborn; Non-specific effect; Trained immunity; Vaccine.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity / drug effects*
  • Adaptive Immunity / genetics
  • Adjuvants, Immunologic / therapeutic use
  • Animals
  • BCG Vaccine / therapeutic use
  • Communicable Diseases / immunology*
  • Epigenesis, Genetic
  • Female
  • Humans
  • Immunity, Heterologous / drug effects*
  • Immunity, Innate / drug effects*
  • Immunity, Innate / genetics
  • Immunization / trends*
  • Mice
  • Pregnancy
  • Pregnancy Complications, Infectious / immunology
  • Pregnancy Complications, Infectious / prevention & control*
  • Prenatal Exposure Delayed Effects / immunology*
  • Toll-Like Receptors / agonists


  • Adjuvants, Immunologic
  • BCG Vaccine
  • Toll-Like Receptors