Immune responses against group B Streptococcus monovalent and pentavalent capsular polysaccharide tetanus toxoid conjugate vaccines in Balb/c mice

Nisha Dhar; Ebrahim Mohamed; Frank Kirstein; Matthew Williams; Shantal Dorasamy; Petrus van Zyl; Madelyn Johnstone Robertson; Taigh Anderson; Lois M Harden; Kimberly Jardine; Balaji Veeraraghavan; Seanette Wilson; Patrick Tippoo; Shabir A Madhi; Gaurav Kwatra

doi:10.1016/j.isci.2023.107380

Immune responses against group B Streptococcus monovalent and pentavalent capsular polysaccharide tetanus toxoid conjugate vaccines in Balb/c mice

iScience. 2023 Jul 13;26(8):107380. doi: 10.1016/j.isci.2023.107380. eCollection 2023 Aug 18.

Authors

Nisha Dhar¹, Ebrahim Mohamed², Frank Kirstein², Matthew Williams², Shantal Dorasamy², Petrus van Zyl², Madelyn Johnstone Robertson², Taigh Anderson², Lois M Harden³, Kimberly Jardine⁴, Balaji Veeraraghavan⁵, Seanette Wilson², Patrick Tippoo², Shabir A Madhi^{1

6}, Gaurav Kwatra^{1

5

6}

Affiliations

¹ South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
² The Biovac Institute, Cape Town, South Africa.
³ Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
⁴ Wits Research Animal Facility, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
⁵ Department of Clinical Microbiology, Christian Medical College, Vellore, India.
⁶ African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.

Abstract

Immunization of pregnant women with Group B Streptococcus (GBS) capsular polysaccharide (CPS) conjugate vaccine (CV) could protect young infants against invasive GBS disease. We evaluated the immunogenicity of investigational five GBS monovalent (serotypes Ia, Ib, II, III, and V) CPS-tetanus toxoid (TT)-CV with adjuvant and GBS pentavalent CPS-TT-CV with adjuvant (GBS5-CV-adj) and without adjuvant (GBS5-CV-no-adj), in Balb/c mice. Aluminum phosphate was the adjuvant in the formulations, where included. The homotypic immunoglobulin G (IgG) geometric mean concentration (GMC) and opsonophagocytic activity (OPA) geometric mean titer (GMT) did not differ after the third dose of the GBS5-CV-adj vaccine compared with the monovalent counterparts for all five serotypes. The GBS5-CV-adj induced higher post-vaccination serotype-specific IgG GMCs and OPA GMTs compared to GBS5-CV-no_adj. The GBS5-CV with and without adjuvant should be considered for further development as a potential vaccine for pregnant women to protect their infants against invasive GBS disease.

Keywords: Immunology; Medical microbiology.