A cost-effectiveness analysis was conducted on a potential group B Streptococcus (GBS) vaccine for the UK. The analysis found that a GBS vaccine is likely to be a cost-effective intervention based on recent UK data on disease burden and healthcare costs. A GBS vaccine covering 5 major serotypes could prevent hundreds of cases of neonatal and maternal GBS disease annually in the UK and gain thousands of quality-adjusted life years at a reasonable cost. Global analyses also indicate GBS vaccination could significantly reduce disease burden worldwide and be very cost-effective in many countries according to WHO guidelines. More research is still needed to define cost-effectiveness in lower-income settings.

1. COST-EFFECTIVENESS OF GBS
VACCINATION
Caroline Trotter
clt56@cam.ac.uk

2. CONTRIBUTORS
Dr Kyriaki Giorgakoudi
Professor Paul Heath
Dr Catherine O’Sullivan
Dr Theresa Lamagni
Ms Hilary Rattue
Dr Mary Ramsay
Dr Shamez Ladhani
Dr Hareth al-Janabi
We thank
for funding

3. OUTLINE
•What/ why cost-effectiveness?
•UK perspective and cost-effectiveness analysis
•Global perspective

4. WHAT IS COST-EFFECTIVENESS?
A cost-effectiveness analysis (CEA) compares the costs and health
effects of an intervention to assess the extent to which it can be
regarded as providing “value for money”.
How can we buy the most health with our NHS money?

5. COST-EFFECTIVENESS ANALYSIS
Slide courtesy of Dr Hannah Christensen
Incremental effects
of intervention
£ per unit
of effect
Incremental cost
of intervention
Quality adjusted life years
(QALYs) gained through
vaccinating
Cost of vaccination -
cost saved from preventing cases
=

6. JCVI PERSPECTIVE
Vaccine decision makers must consider evidence on cost-
effectiveness
 alongside evidence on safety, immunogenicity, efficacy, disease burden, indirect
effects
 If a recommended vaccine programme is shown to be cost-effective, DH obliged
to implement
In principle follow NICE rules
 Some specific guidelines for vaccination, such as on uncertainty
 Takes perspective of health service (not society)

7. THE CASE FOR A GBS VACCINE IN THE UK
GBS is an important cause of invasive disease in neonates with ~750
cases each year in the UK, 5-10% case fatality, high rate of adverse
neurodevelopmental outcomes in survivors
Current prevention = risk based intrapartum antibiotic prophylaxis
(IAP)
Universal screening an alternative but primary prevention through
vaccination has greater potential to prevent invasive disease (in
neonates and mothers)
Need to avoid excessive antibiotic use in context of AMR

8. MATERNAL IMMUNISATION
Pertussis and influenza currently offered to pregnant women in UK
Tetanus vaccine widely used in pregnancy globally
Buoyant landscape with maternal vaccines in development for a range
of infections including RSV and GBS

9. GBS VACCINES IN DEVELOPMENT
A range of vaccines are in development (Heath PT, Vaccine 2016)
Leading candidates are protein-polysaccharide conjugates
 Trivalent conjugate vaccine has completed phase I and II trials
 Now reformulated to pentavalent
 An alternative approach is targeting surface expressed proteins, in an attempt to
confer broad protection across all serotypes
Licensure may require efficacy trials or be based on serological
correlates of protection
 next talk!

10. DECISION TREE
We concentrate on these outcomes in
primary analysis AND include
maternal disease. We include stillbirth
and prematurity prevention in scenario
analyses

11. PRIMARY DATA SOURCES
Neonatal disease Maternal disease Health costs Vaccine costs
Incidence and case
fatality from latest
BPSU study
(O’Sullivan et al,
submitted)
HES data linked to
laboratory
confirmed cases
(PHE)
NHS reference
costs
Vaccine delivery
costs from other
maternal
immunisation
programmes
Long term disease
outcomes from
MRF-funded
follow-up study
Literature Unit costs of health
and social care
Vaccine cost per
dose unknown so
threshold cost
investigated
Literature Literature,
especially
Schroeder et al.
Eur J Health Econ
(2009)

12. BASE CASE SCENARIO
EOD 0.58/ 1000 livebirths, 4.4% CFR, 5.5% /9.6% severe/
moderate sequelae, acute healthcare costs ~£12,000
LOD 0.39/ 1000 livebirths, 7.6% CFR, 5.3% / 9.2% severe/
moderate sequelae, acute healthcare costs ~£12,000
Maternal disease 0.27/1,000 maternities, acute healthcare costs
~£2500
Potential adverse effects of vaccination and litigation costs paid by
the NHS were included.
Vaccine covers 5 serotypes (96%) is 85% effective with 60%
uptake, 1 dose required each pregnancy

13. IMPACT ON DISEASE
In the base case scenario, in one year, maternal GBS immunisation will
prevent:
•369 cases of GBS among infants
• Including 179 cases with sequelae.
• And 21 infant deaths
•103 maternal cases will also be avoided.
•In total, 795 life years and 870 QALYs will be gained.

14. INCIDENCE VS EFFICACY

15. UNCERTAINTY ANALYSIS £20,000
per QALY
£30,000
per QALY

16. SUMMARY OF UK STUDY
GBS vaccination is likely to be a cost-effective intervention for the
prevention of invasive neonatal and maternal GBS disease
+ Many parameters are based on recent, high quality studies.
- The costs of aftercare for survivors with sequelae are not well
defined.
These results should encourage manufacturers, especially in context of
global interest in the development of GBS vaccines

17. GLOBAL PERSPECTIVE
Major effort to quantify global GBS
disease burden
“A maternal vaccine with 80% efficacy
and 90% coverage could prevent
107000 (UR, 20000–198000) stillbirths
and infant deaths”
South African CEA concluded “Vaccination
would substantially reduce the burden of
infant GBS disease in South Africa and
would be very cost-effective by WHO
guidelines” Kim et al 2014

18. CONCLUSIONS
Cost-effectiveness analyses support development and implementation
of GBS vaccines
In the UK the current analyses suggest a reasonably high threshold
price
More work to be done to define cost-effectiveness in lower and
middle income countries but new burden of disease studies are a big
asset