Hyporesponsiveness

In immunology, hyporesponsiveness refers to an immune tolerance that occurs after repeated immunizations with polysaccharide vaccines (Brynjolfsson SF et al. 2012). After vaccinations with meningococcal polysaccharide and many pneumococcal polysaccharide serotypes, this pahenomenon is observed (Richmond P et al. 2000). Hyporesponsiveness after vaccination with Haemophilus influenzae type b polysaccharide has not been observed directly but may follow exposure during illness in some individuals. Furthermore, introduction of polysaccharide vaccines at any point in a schedule of conjugate vaccines may result in reduced immune responses upon subsequent exposure.

1. Brynjolfsson SF et al. (2012) Hyporesponsiveness following booster immunization with bacterial polysaccharides is caused by apoptosis of memory B cells. J Infect Dis 205:422-430.
2. Richmond P et al. (2000) Meningococcal C Polysaccharide Vaccine Induces Immunologic Hyporesponsiveness in Adults That Is Overcome by Meningococcal C Conjugate Vaccine.The Journal of Infectious Diseases 181: 761-764,