introduction of new vaccines
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Introduction of New vaccines
Hib as an ExampleSt. Petersburg25-27 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
56789
10111213
1975 1980 1985 1990 1995 2000
Established Market
Developing CountriesVaricella
Acell pertussisPneumococcal *meningoccoal C*
MeaslesDPTPoliomyelitisBCG
Hepatitis B**
MeaslesMumpsRubellaDPTPoliomyelitis
Haemophilus InfluenzaeHepatitis B
*Estimated future use **Used in ~ 50% of global birth cohort
Estimated rate (children<5) > 200/100,000100-200/100,00045-100/100,000< 45/100,000
Hib meningitis and pneumonia burden
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
>$6000 $1000-$6000 <$1000
0
20
40
60
80
%HibHep B
Causes of death in children less than 5 years old
ARIDiarrheaVPDPerinatalOther
19%
20%
20%
13% The Global Burden of DiseaseMurray and Lopez, editorsTotal - 12.8 million
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’)
Hib vaccine efficacy studies: Protection against invasive
disease
0%10%20%30%40%50%60%70%80%90%
100%
Gambia Chile USA USA UnitedKingdom
• Hib vaccines have proven their 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
0
10
20
30
40
50
60
Cases
prevented
Invasive Disease X-ray pneumonia
HIB cases prevented
95% efficacy
21% efficacy
Source: Mulholland et al. Lancet 1996
Impact of Hib vaccineon Hib meningitis in Uruguay
0
10
20
30
40
50
60
1991 1992 1993 1994 1995 1996
Year
No. Cases
Source: PAHO
Routine Hib vaccination started - with ‘catch up’
Other conjugate vaccines already in use
• Meningococcus– routine infant immunization in UK, Spain,
Ireland• Pneumococcus
– routine infant immunization in USA
WHO European Region
Mean annual incidence of Hib meningitis per 100 000 in children <5 years of age
3028 27 27
2220 19
1715
13 12 119 8 8 8 8 7 7 6 6
1 1
14
0
10
20
30
40
50
60
70
Sweden
Switzerl
and
Denmark
Finlan
d
Netherl
ands
UK
Israe
l
Slovak
ia
France
Austria
Repub
lic of
Irelan
d
Sloven
iaMalt
a
German
ySpa
inIta
ly
Greece
Russia
n Fed
eratio
n
Czech
Rep
ublic
Poland
Bulgari
a
Hunga
ryLa
tvia
Region
al mea
n
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