The Power of Vaccines: ‘getting to zero’ for HIV and TB was an event hosted by the TB/HIV and Prevention Working Groups of the UK Consortium on AIDS and International Development. The meeting was sponsored by Pamela Nash MP and held on Friday, 18th May 2012, in Portcullis House, Westminster. Read more at http://storify.com/PamojaUK/the-power-of-vaccines http://www.pamoja.uk.com

1. Why the world needs
vaccines for TB
The Power of Vaccines: ‘getting to zero’ for HIV and TB
TB-HIV Working Group
UK Consortium on AIDS and International Development
World AIDS Vaccine Day
May 18th 2012
Dr Richard White
TB Centre
Centre for the Mathematical Modelling of Infectious Disease
Department of Infectious Disease Epidemiology
London School of Hygiene and Tropical Medicine
Richard.White@lshtm.ac.uk
Improving health worldwide
www.lshtm.ac.uk

2. Why the world needs
vaccines for TB
• Global TB burden
• Global TB control targets
• How are we doing?
• TB ‘Elimination’ - what do models have to say about how
we might get there?
• Summary

3. Global TB burden (2010)
10.0
8.8
Estimated number cases and
9.0 All forms TB
8.0 HIV associated TB
deaths, Millions
7.0 Multidrug resistant TB
6.0
5.0
4.0
3.0
2.0 1.1 1.45
1.0 0.44 0.35 0.15
0.0
TB disease cases Deaths
WHO. Global tuberculosis control 2011.
Geneva.

4. Global TB disease
incidence by region (2010)
Americas, 5%
Europe, 5%
Eastern
Mediterranean, • Highest burden in Asia
7%
– 59%
South-East Asia, • Highest rates in Africa
40%
– About 80% of cases HIV infected
Africa, 26%
Western Pacific,
19%
WHO. Global tuberculosis control 2011.
Geneva.

5. Why the world needs
vaccines for TB
• Global TB burden
• Global TB control targets
• How are we doing?
• TB ‘Elimination’ - what do models have to say about how
we might get there?
• Summary

6. Global TB control
targets
• UN Millennium Development Goals
– 2015: … begun to reverse [rising TB] incidence
• Stop TB Partnership
– 2015: 50% reduction in TB prevalence and deaths
– 2050: Elimination of TB ‘as a public health problem’ (<1 case per million people)

7. Why the world needs
vaccines for TB
• Global TB burden
• Global TB control targets
• How are we doing?
• TB ‘Elimination’ - what do models have to say about how
we might get there?
• Summary

8. How are we doing?
Strategy
WHO (2006). The Stop TB Strategy, WHO / Stop
TB. Geneva

9. How are we doing?
Progress in 2011
• 46 million people successfully treated (1995-2010)
• ~7 million lives saved compared to 1995 standard of care
• Millenium Development Goals (declining TB disease in 2015)
– Peak in ~2002
– On track
• Stop TB (50% reduction in mortality between 1990 and 2015)
– Reduced by 40% since 1990 in 2006
– On track
WHO. Global tuberculosis control 2011.
Geneva.

10. How are we doing?
Global estimated TB disease incidence,
prevalence and mortality
TB disease incidence TB disease prevalence TB mortality
Currently ~1%
annual
decline Target Target
40% decline since
1990
But
• TB disease incidence decline very slow
• Case detection improvements slowing
• MDR-TB care only now scaling up
WHO. Global tuberculosis control 2011.
Geneva.

11. Why the world needs
vaccines for TB
• Global TB burden
• Global TB control targets
• How are we doing?
• TB ‘Elimination’ - what do models have to say about how we
might get there?
• Summary

12. What can we achieve with the
existing strategy?
Current decline (1%/yr)
Predicted decline with
full implementation of
Global Plan to Stop TB
(6%/yr)
Decline required for
‘Elimination’ (16%/yr)
Lonnroth et al, Social Science and Medicine, 2009

13. ‘Elimination’ by 2050
What would it take?
• Impact of treating active TB
disease cases OR using new
pre-exposure vaccine large
• But impact limited as neither
directly prevents reactivation
‘Elimination’ disease among latents (1 in 3
people worldwide)
• ‘Elimination’ unlikely
• Elimination more likely if
• Combination prevention
approach used that
a) Prevents reactivation
disease among latents using
preventative drug therapy OR a
post-exposure vaccination
AND
b) Prevents/treats active
disease using a new pre
exposure vaccination OR drug
Dye et al, J R Soc Interface, 2008 therapy

14. Potential impact of new TB diagnostics,
drugs and vaccines on TB disease
incidence in SE Asia in 2050
Diagnostics
Disease incidence (/million)
• Dipstick point of care test
• 42% ↓ in TB incidence
) at microscopy lab level
point of care test
Drugs • 2 month active disease therapy
Disease incidence (/million)
(including M/XDR) & mass
latent therapy
Active disease #1: 4 month, no MDR effect
Active disease #2: 2 month, 90% MDR effect
Active disease #3: 10-day, 90% MDR effect
• 94% ↓ in TB incidence
Vaccines
Disease incidence (/million)
• Mass pre and post exposure
vaccines
+ latency & case infectiousness effect • 92% ↓ in TB incidence
Abu-Raddad et al, Proc Natl Acad Sci, 2009

15. Why the world needs
vaccines for TB
• We should meet the (rather underwhelming) target of slow
annual reduction in global TB disease incidence in 2015
• Using current tools we are unlikely to get close to eliminating
TB disease as a public health problem by 2050
• Can get closer to elimination using combination-prevention
strategies that prevent/treat active disease AND prevent
disease due to reactivation of latent infection
• But, to do so we would need strategies like
– mass treatment of latent MTB infection OR new post-exposure vaccine
AND
– high coverage of effective disease therapy OR new pre-exposure vaccine
• Of these DOTS coverage increase has stalled, and mass
treatment of latent MTB infection is difficult to scale up
=> New vaccines, drugs and diagnostics are required
Improving health worldwide
www.lshtm.ac.uk

16. Why the world needs
vaccines for TB
Dr Richard White
TB Centre
Centre for the Mathematical Modelling of Infectious Disease
Department of Infectious Disease Epidemiology
London School of Hygiene and Tropical Medicine
Richard.White@lshtm.ac.uk
Improving health worldwide
www.lshtm.ac.uk