Transcript Introduction of New vaccines - VHPB News | Viral Hepatitis

Introduction of New vaccines
Hib as an Example
St. Petersburg
25-27 Jun 2001
Vaccines use in the world
• For the past two decades, in most
developing countries, vaccination restricted
only to the initial EPI vaccines
• Where-as in most developed countries,
several new vaccines such as HepB, Hib,
meningococcal, pneumococcal, were
gradually added to the initial EPI vaccines,
• Thus widening the gap in protection against
infectious diseases between the rich and the
poor
Number of Childhood Vaccines Routinely Used
in Developing and Established Market Countries
Acell pertussis
Pneumococcal *
meningoccoal C*
13
12
Established Market
11
Developing Countries
10
9
8
7
6
Varicella
Haemophilus Influenzae
Hepatitis B
Measles
Mumps
Rubella
DPT
Poliomyelitis
Hepatitis B**
Measles
DPT
Poliomyelitis
BCG
5
1975
1980
1985
1990
1995
2000
*Estimated future use
**Used in ~ 50% of global birth cohort
Hib meningitis and pneumonia burden
Estimated rate (children<5)
> 200/100,000
100-200/100,000
45-100/100,000
< 45/100,000
Countries using Hib vaccine in their
national immunization system, 2000
Why this difference?
• Failure to demonstrate efficacy in
developing country settings early in the
course of vaccine development;
• Lack of disease burden data, or
awareness of disease burden in
developing countries
• Failure to account for production for the
developing world
Why this difference?
• Relatively higher prices of new vaccines;
and
• Lack of technical advice and guidance on
introduction of new vaccines
Proportion of Countries introducing
Hep B and Hib, by per capita GNP
80
60
% 40
Hib
Hep B
20
0
>$6000
$1000$6000
<$1000
Causes of death in
children less than 5 years old
20%
20%
ARI
Diarrhea
VPD
Perinatal
Other
19%
13%
Total - 12.8 million
The Global Burden of Disease
Murray and Lopez, editors
Bacterial Meningitis
• Haemophilus influenzae type b (Hib)
– 30% -50% of bacterial meningitis
• Pneumococcus
– 25- 35% of bacterial meningitis
• Meningococcus
– 25 - 35% of bacterial meningitis (except
during epidemics)
Pneumonia
• Haemophilus influenzae type b (Hib)
– 20-25% of all severe bacterial pneumonia
– Gambia, Chile, other studies pending
• Pneumococcus
– ? 50-60% of severe bacterial pneumonia
– South Africa, Gambia, Philippines, etc
• Others (RSV, adenovirus, etc)
Hib in the world
• Global burden of disease
– Most common cause of bacterial meningitis in
children
– Second most common cause of serious
bacterial pneumonia in children less than five
years of age
– Total - estimated 400,000-500,000
deaths/year in children less than five
Hib vaccines: Safety and
Effectiveness
• Hib vaccines are safe and easily
administered within existing regimens
• Hib vaccines have high efficacy against:
–
–
–
–
Meningitis
Pneumonia
Bloodstream infections
Carriage
• Hib vaccines have prevented disease in
unimmunized persons (‘herd immunity’)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Hib vaccine efficacy studies:
Protection against invasive
• Hib vaccines have
disease proven their
Gambia
Chile
USA
USA
United
Kingdom
effectiveness in careful
studies in Africa,
South America, No.
America and Europe
• Hib vaccines provide
90-100% protection
against invasive Hib
disease
Hib Conjugate vaccines
• Eliminate bacterial meningitis as a
public health problem
• Reduce largest single remaining cause
of infant mortality (pneumonia) by over
80%
• Safe, immunogenic and highly effective
• Widely used in industrialized countries
Hib vaccine efficacy in the Gambia:
Protection against pneumonia and invasive
disease
21% efficacy
60
C
a
s
e
s
p
r
e
v
e
n
t
e
d
50
40
95% efficacy
30
20
10
0
Invasive Disease
X-ray pneumonia
HIB cases prevented
Source: Mulholland et al. Lancet 1996
Impact of Hib vaccine
on Hib meningitis in Uruguay
60
Routine Hib
vaccination
started - with
‘catch up’
50
40
No.
Cases
30
20
10
0
1991
1992
1993
Year
Source: PAHO
1994
1995
1996
Other conjugate vaccines already
in use
• Meningococcus
– routine infant immunization in UK, Spain,
Ireland
• Pneumococcus
– routine infant immunization in USA
WHO European Region
70
60
Mean annual incidence of Hib meningitis per 100 000 in children <5 years of age
50
40
30
30
28
27
27
22
20
10
20
19
17
15
13
12
14
11
9
8
8
8
8
7
7
6
6
1
0
1
The situation in CEE, NIS
•From available data, Hib does not appear
to be a major public health problem
•This could be real or fictitious
•If fictitious, the reasons could be
–problem in the collection of csf
–lack of lumbar puncture for suspected
cases
–problem with laboratory technique
Where do we go?
• Surveillance for Hib disease
• Further studies
• Hib immunisation needs for special
situations- day care centres, special
paediatric units
The available tools
• Generic protocol for Pop based Hib
studies
• HibRAT for quick assessment of the
Hib burden based on retrospective
analysis of laboratory data
• Management guidelines for those
countries that are already using the
vaccine