# Development of a Group B Streptococcus bioconjugate vaccine

> **NIH NIH R44** · VAXNEWMO, LLC · 2024 · $995,682

## Abstract

PROJECT SUMMARY
Streptococcus agalactiae, commonly referred to as Group B Streptococcus (GBS), is a leading cause of neonatal
meningitis and sepsis worldwide. GBS neonatal disease manifests as early onset invasive disease, defined as
disease between birth and 6 days of life, or late onset invasive disease, defined as disease occurring between
7 and 89 days. In some instances, early onset disease is preventable with intrapartum antibiotic prophylaxis;
however, this treatment strategy is not practical for low- and middle-income countries, which account for 95% of
all neonatal GBS infections, nor does it prevent late onset disease. Three GBS serotypes (type Ia, Ib, and III)
account for >60% of all early-onset and >90% of all late-onset invasive GBS infections. As such, a low-cost
vaccine strategy to prevent the majority of invasive GBS neonatal disease associated with these three serotypes
would be a valuable therapeutic intervention option. Conjugate vaccines, composed of polysaccharides
covalently linked to carrier proteins, are life-saving vaccines used to prevent disease from multiple bacterial
pathogens. Conjugate vaccines are conventionally manufactured using chemical conjugation, which is
notoriously complex, labor intensive, and costly, hindering the development of new conjugate vaccines. Aware
of these drawbacks, VaxNewMo has been advancing an alternative method for manufacturing conjugate
vaccines that utilizes prokaryotic glycosylation systems in a process termed bioconjugation. VaxNewMo’s
proprietary bioconjugation platform relies on a conjugating enzyme to transfer bacterial polysaccharides to
engineered carrier proteins using E. coli as a host. Moreover, since bioconjugation is an enzymatic process, the
conjugates produced are non-derivatized and the polysaccharides are structurally identical to those presented
to immune cells by the pathogen itself. In Phase I, we developed a prototype trivalent (serotypes Ia, Ib, and III)
bioconjugate vaccine and demonstrated that it was immunogenic, elicited functional antibody responses towards
all three GBS serotypes, and protected newborn mouse pups from invasive serotype III GBS disease. In Phase
II, we will produce type Ia-, Ib-, III-bioconjugates using an improved, di-glycosylated carrier protein design that
mimics the final formulation, establish bioprocessing capabilities and downstream purification processes, as well
as perform pre-IND enabling studies in mice. In Aim 1, we will optimize production of the GBS Ia, Ib and III
bioconjugate vaccines, moving from shake flasks to more industrial fed-batch bioreactor systems, remove
histidine tags from the bioconjugates (which are not acceptable in marketed vaccines for human use), and
establish downstream purification processes as well as characterize vaccine quality attributes. In Aim 2, we will
perform dose-escalation studies in mice using monovalent and trivalent formulations of GBS bioconjugate
vaccines produced on the improved, di-glycosylat...

## Key facts

- **NIH application ID:** 10867314
- **Project number:** 5R44AI142928-04
- **Recipient organization:** VAXNEWMO, LLC
- **Principal Investigator:** Christian Harding
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $995,682
- **Award type:** 5
- **Project period:** 2019-03-12 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10867314

## Citation

> US National Institutes of Health, RePORTER application 10867314, Development of a Group B Streptococcus bioconjugate vaccine (5R44AI142928-04). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10867314. Licensed CC0.

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