This document provides a summary of a presentation on prospects for developing a Group B Streptococcus (GBS) vaccine for pregnant women globally. It notes that GBS is a leading cause of neonatal infections and discusses the limitations of the current prevention strategy using intrapartum antibiotics. Developing a maternal GBS vaccine could have a higher impact by preventing more outcomes and providing more equitable coverage. Ongoing work includes further vaccine development and clinical trials, establishing a global disease burden, developing standardized assays to assess vaccine protection, and guidance for vaccine policy and implementation. The goal is to develop a safe and effective maternal GBS vaccine to reduce infant mortality from this disease worldwide.

1. Prospects for GBS prevention - current candidates
& removing barriers to licensure of a GBS vaccine
for pregnant women globally.
Kirsty Le Doare
Centre for International Child Health,
Imperial College London
Thank you to Prof Shabir Madhi and Prof Joy Lawn for sharing slides to be included in this presentation

2. Why this organism ?
#GBSburden #momandbaby
• Commonly found in
gut or lower vaginal
tract
• Leading cause of
neonatal infections
Early Onset and Late
Onset (sepsis,
meningitis) in many
countries with high
case fatality rate

3. Meningitis in young infants
GBS:
86%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
<2mo
Percentageoftotalcases
GBS:
78%
USA 2003-07
UK & ROI 2010-11Cases < 2 months of age
NEJM 2011;
364:
2016-2025
Clin Infect Dis
2014;15;
59(10):50-7

4. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2002 2004 2006 2008 2010 2012 2014
Intrapartum Antibiotic Prophylaxis (IAP) Reduces Early-Onset Disease
(EOD), but does Not Prevent Late-Onset-Disease (LOD)
Rate of Early- and Late-Onset GBS, US 1990-2014*
*CDC Active Bacterial Core surveillance / Emerging Infections Program
Early-onset GBS ~80% reduction
of early-onset
disease
Late-onset GBS
IAP
effectiveness
continues to
plateau in 2016*
Before national prevention policy Transition Universal screening
~30% of pregnant women
receive antibiotics

5. Why pursue a maternal GBS vaccine?
1. Higher impact than IAP as affects more outcomes
2. Higher coverage especially in challenging settings  more equitable than IAP
3. Leverage existing programmatic platforms (e.g. antenatal care)
4. Reduce antibiotic exposure (21.7 million women)
Could be
prevented by IAP
Could be prevented by
maternal GBS vaccine

6. MI COMPLEMENTS EXISTING VACCINES AND
INTERVENTIONS1 IN THE CONTINUUM OF MOTHER-INFANT
CARE
MI could be a key
component of the
continuum of care
Vulnerability zone
(up to 3 months)
Too early for childhood
vaccines
Continuum of care
Obstetric, childbirth, and essential newborn care
Clean birth
In-facility and community
ANC
Neonatal sepsis prevention and treatment
Pregnancy home visit
Pregnancy Infant
Childhood vaccines / EPI
6 wksBirth 10 wks 14 wks
Protection from maternal immunization
MI may provide protection
until childhood vaccines
Early and late postnatal care for mother and newborn
Care of newborn, infant and child
GBS
RSV
Tetanus
1. Maternal Newborn Child Health; Source: Every Newborn: An action plan to end preventable deaths (2013).

7. Vaccines targeting disease-associated bacterial antigens can
reduce severe disease and clones associated with
antimicrobial resistance
© Bill & Melinda Gates Foundation |
Acquisition of Tetracycline resistance (TcR) led to expansion of hypervirulent CC17
clones followed by the emergence of neonatal GBS disease in the 1960s1
1Da Cunha V, Nat comm 2017; 2Almeida A, msystems ASM 2017
- In HIC ~32% of pregnant
women receive intrapartum antibiotics
(Penicillin) to protect their newborn infants
against GBS disease
- Emerging resistance to second-line
antibiotics
Presence of CC17 correlates with cases
of LOD and meningitis2
GBS glyco-conjugate vaccine targeting CC17 isolates (Type III and IV)
Decreased use of antibiotics and less severe disease
Severe GBS
disease
Potential
resistance

8. Basis for immunological intervention of invasive GBS
disease in infants
• IgG antibodies are uniquely transferred to the fetus during the
3rd trimester1,2
• Functional anti-CPS antibodies may protect the mother from
infection and prevent acquisition of new strains via
opsonophagocytosis3
1Palmeira et al. 2012; Clin Dev Immunol 985646; 2Roopenian 2007; Nature Rev Immunol 7, 715; 3Baltimore et al 1977; J Immunol 118, 673

9. How many GBS deaths could be prevented?
0
20
40
60
80
100
120
Maternal GBS disease
deaths
Stillbirths with GBS Early onset GBS deaths Late onset GBS deaths
Deathsprevented(thousands)
Not estimated
Current approach (IAP) prevents 29 000 (UR, 0–51 ]000) early onset GBS cases
A maternal vaccination could prevent 231 000 (UR, 114 000–507 000) infant and maternal GBS cases, 41 000
(UR, 8000–75 000) stillbirths , 66 000 (UR, 12 000–123 000) infant deaths
Seale AC et al Clinical Infectious Diseases. 2017;65(S2):S200-19

10. Example of vaccine cost-effectiveness

11. Where do we go from here?
Focus area Activity
Improved data on the
burden
- Neonatal and stillbirth cause-of-death studies
eg CHAMPS network
- Cohort studies for impairment outcomes
- Whole genome sequencing
Value proposition - Global value proposition, WHO
- Additional burden and Cost-effectiveness modeling
Vaccine development - Validate path to licensure
Policy, guidance and
norms
- WHO Preferred Product Characteristics, technical R&D
roadmap
- Support for WHO activities to facilitate GBS vaccine
development, licensure, and prequalification with a focus on
LMIC
Standardised assays for
assessment of a correlate
- International collaboration to harmonise reagents and
methods for the assessment of antibody against GBS
- Aim to predict a serocorrelate of protection against disease for
the most common serotypes

12. Momentum since PDVAC 2016 on GBS
1. Develop preferred product characteristics (PPC) for GBS vaccine
2. Finalisation of the GBS Vaccine Development Technology Roadmap
3. Advance planning for WHO pre-qualification, policy making, implementation:
• Identify key gaps and define implementation research agenda
• Need to build stakeholder commitment, a GBS vaccine community
4. Completion of global burden of disease estimates – maternal, stillbirths and infants.
5. Work-in-progress on GBS assay standardisation, including reference sera.
6. Further reports on tri-valent GBS vaccine in pregnant women, including antibody
kinetics in women and infants, and impact of interference to childhood vaccines.
7. Phase I study on GBS common protein (AlpC and Rib) vaccine in pregnant women,
and first-in-human studies of higher valency (>3 serotypes) polysaccharide-protein
conjugate vaccine.

13. GBS is an underestimated cause of neonatal infection,
maternal infection and stillbirth
Courtesy: Anna Seale & Joy Lawn
• 33,000 maternal disease
• 57,000 stillbirths
• 319,000 infant disease
• 90,000 infant deaths

14. Value Proposition of GBS (and other)Maternal
Immunization (MI)
4
MI may protect infants <5-mo
against infection-related deaths
MI may also prevent a portion of
preterm birth and infection-
related stillbirths (10 – 50%1 of
the overall stillbirths)
MI can have an impact on
maternal morbidity and
mortality
1. McClure EM, "Stillbirth in Developing Countries: A review of causes, risk factors and prevention strategies" , J. of
Matern Fetal Neonatal Med. (2014); 2. WHO-CHERG 2013
Global neonatal mortality2
Infection
related
606K
(22%)
Pre-term births
965K
(35%)
Other
1,190K
(43%)

15. GBS vaccine development pipeline
© Bill & Melinda Gates Foundation |
http://www.who.int/immunization/research/development/ppc_grou
pb_strepvaccines/en/

16. Newborn antibody concentrations
49–79% of maternal levels
0
2.5
5
7.5
10
GMC
(ug/ml)
30-32wk
delivery
cord
infant1month
infant2months
GBS conjugate vaccines in
pregnant women

17. GBS Serotype Ia antibodies In HIV-uninfected and HIV-infected
Mothers and their infants with one 5.0 µg dose of GBS vaccine
Mothers InfantsELISAGMC(µg/mL)
HIV+ High CD4+ HIV+ low CD4+HIV uninfected
Day 1 Day 15 Day 31Delivery
0
2
4
6
8
10
Day 1 Day 42
0
2
4
6
8
10
Similar immunogenicity trends observed for serotypes Ib and III
Transfer Ratio 0.72 (0.61–0.85) 0.58 (0.49–0.69) 0.60 (0.51–0.72)
Adapted: Heyderman R, Madhi SA et al. Lancet Infect Dis 2016; 16:
Increased risk of invasive GBS Disease in HIV-exposed infants:
Early-onset disease: RR: 1.69 (95%CI: 1.3-2.2)
Late-onset disease: RR: 3.18 (95%CI: 2.3-4.4) Cutland C et al Emerg Infect Dis; 2015: 21: 638-645

18. Sample Size Calculation for an Efficacy Trial for an
Invasive Disease Outcome
Vaccine efficacy
(lower bound 20% VE)
Incidence
(per 1000 births)
Approximate
Sample Size N (1:1)
(+10%)
80%
1 44,000
1.5 29,000
2 22,000
3 14,700
4 11,000
70%
1 70,000
1.5 46,500
2 35,200
3 23,000
4 17,500
Serocorrelates of protection against disease are needed

19. Baker et al. (USA) J Infect Dis 2014 Dangor Z et al. (South Africa) Vaccine 2015
Serotype Ia: 90% reduced risk if ≥5 ≥3 µg/mL.
Serotype III: 90% reduction in risk .
Serotype Ia: 89% reduced risk if ≥0.5 µg/mL.
Serotype III: 91% reduced in risk if ≥0.5 µg/mL.
Need for Standardized Immunology Assays to Establish Correlate
of Protection Against Invasive GBS disease.

20. stakeholders
Steering group Technical advisory group
Shabir Madhi (co-PI)
Beate Kampmann (co-PI)
Paul Heath (co-PI)
David Goldblatt - UCL
Moon Nahm - Birmingham
Freya Williams - FDA
Fatme Mawas - NIBSC
Carol Baker - Baylor
Luke Williams – PHE IAG
Ivana Knezevic - WHO
WHO PATH BioVac Industry
BMGF
Kirsty Le Doare (PI)
Andy Gorringe (co-PI)
Gaurav Kwatra (co-PI)
= collaborators

21. Paper 1: Group B Streptococcal disease worldwide for pregnant women, stillbirths and
children:
why, what and how to undertake estimates?
Paper 11: Estimates of the burden of Group B Streptococcal disease worldwide
for pregnant women, stillbirths and children
Lawn JE, et al Clinical Infectious Diseases. 2017;65(S2):S89-99
Overview of papers in CID – open access and launched
2. Maternal colonisation with Group B Streptococcus and serotype distribution worldwide
3. Maternal disease with Group B Streptococcus and serotype distribution worldwide
4. Stillbirth with Group B Streptococcus disease worldwide
5. Preterm birth associated with Group B Streptococcus maternal colonisation worldwide
6. Intrapartum antibiotic chemoprophylaxis policies for prevention of Group B Streptococcal
Disease worldwide
7. Risk of early-onset neonatal Group B Streptococcus disease with maternal colonisation
worldwide
8. Infant Group B Streptococcal disease incidence and serotypes worldwide
9. Neonatal encephalopathy with Group B Streptococcus disease worldwide
10. Neurodevelopmental impairment in children after Group B Streptococcus disease worldwide

23. 1st International Symposium on
Streptococcus agalactiae Disease
(ISSAD)
Cape Town, South Africa
Dates: 20th -23rd February 2018