熱帯病ワクチンの現状と課題

Overview

Introduction

Tropical diseases account for around 5 million deaths per year (WHO, 2002). Major contributors to these numbers are the mosquito borne diseases, which include West Nile Fever, Japanese Encephalitis, Yellow Fever, Dengue and Malaria. Small pox, caused by the Variola virus, although officially eradicated since 1980, still poses a distinct threat as part of bioterrorist attack.

Scope

• Comparative analysis of epidemiology, current disease management and unmet needs analysis in five selected tropical diseases
• Characterization of existing vaccines and demand drivers for newer generation products in smallpox, yellow fever and Japanese encephalitis
• Critical overview of need for preventative vaccination in malaria, dengue and West Nile River virus
• Ball park estimation of selected vaccine revenue potential per target segment

Report Highlights

Despite their enormous impact on global health, preventative vaccination in the five major tropical diseases is either non-existent or outdated.

The increased incidence and geographical spread of tropical diseases coupled with elevated international travel, urbanization and the threat of bio-terrorism demands for increased levels of preventative action.

Bearing in mind existing revenues, smallpox stockpiling and maintenance and newer vaccines, Datamonitor estimates the tropical defense segment can provide an additional $2.6-2.9 billion over the next 7-10 years.

Reasons to Purchase

• Compare and contrast epidemiological parameters of five major tropical diseases and their global impact on human health
• Understand drivers for newer generation smallpox vaccines and demands of the US BioShield Act
• Understand the benefits and limitations of existing vaccines and need for further preventative measures in target groups

Table of contents

ABOUT DATAMONITOR HEALTHCARE

• About the Infectious Disease pharmaceutical analysis team

EXECUTIVE SUMMARY

• Scope and coverage of the Brief
• Key findings about niche vaccines
• The five major mosquito-borne tropical diseases exert devastating effects on global health where diseases such as malaria and dengue are endemic in 100 countries covering 2-3 billion people. Increased incidence and geographical spread coupled with elevated international travel, urbanization and the threat of bio-terrorism demands for increased levels of preventative action;
• In developing countries poor healthcare infrastructure generally prevents supportive treatment and distribution of older vaccines. Pathogen resistance can also impact the usefulness of drug therapies especially antimalarials. In all regions, the elderly, young children and immunocompromised are disproportionately affected by tropical diseases and receive the least benefit from the few preventative measures available
• For existing JE, YF and smallpox vaccines higher target coverage in at-risk and traveler groups calls for development of safer, more applicable products. In addition, the recent US BioShield Act clearly demonstrates that backing of a powerful sponsor can introduce much-needed political will that is ideally extended to vaccines for malaria and dengue. Bearing in mind existing revenues, smallpox stockpiling and maintenance and newer vaccines, Datamonitor estimates this segment can provide an additional $2.6-2.9 billion over the next 7-10 years
• KEY METRICS

SMALLPOX

• Disease definition
• Etiology and transmission
• Disease progression and clinical manifestations
• Epidemiological overview
• Although smallpox as a disease has been eradicated, fears of an outbreak persist
• The threat of bioterrorism has led the US Government to build an extensive smallpox vaccine stockpile
• Current market overview
• Smallpox can be prevented but not treated
• Investigational smallpox therapies focus on the disease itself or the adverse events associated with vaccination
• Safety issues associated wity smallpox vacciantion have prompted the development of a safer vaccine
• Traditional, live smallpox vaccines are associated with a significant risk of adverse events, in particular in the immunocompromised
• Second- and third-generation smallpox vaccines
• Future market outlook
• Global market visibility for smallpox vaccines
• The US is the only market offering clear visibility for stockpiling of a smallpox vaccine with its RFP programs
• The smallpox vaccine market potential outside the US is uncertain
• The WHO proposes a virtual stockpile

WEST NILE VIRUS

• Disease definition
• Etiology and transmission
• Disease progression and clinical manifestations
• Advanced age is the main risk factor for severe WN disease
• Epidemiological overview
• The West Nile virus has spread from the Eastern to the Western Hemisphere
• Current market overview
• Neither prophylaxis nor therapy is currently available
• Estimation of the economic impact of WNV
• Future market outlook
• Market potential for a prophylactic WNV vaccine
• Three candidate vaccines are undergoing Phase I trials
• The at-risk population constitutes a significant WNV vaccine market

JAPANESE ENCEPHALITIS

• Disease definition
• Etiology and transmission
• Disease progression and clinical manifestations
• Epidemiological overview
• The incidence of Japanese encephalitis is highly heterogeneous
• JE predominantly affects Asia
• JE is a rare event in the West
• Age, location and duration of stay in an endemic area determines the relative risk of JE infection
• Current market overview
• Prevention of disease progression is through effective vaccination
• In the absence of specific therapies...
• ...vaccination is the most effective way of preventing severe JE
• Future market outlook
• JE vaccine market growth in the US and Europe is fuelled by travelers and new vaccine launches
• The launch of Acambiss Chimerivax-JE is expected to have a significant impact on the US & European JE vaccines market

YELLOW FEVER

• Disease definition
• Etiology and transmission
• Disease progression and clinical manifestations
• Epidemiological overview
• The extent of the yellow fever epidemic is largely underestimated
• Current market overview
• Prevention can be achieved through effective vaccination
• Contraindications for YF vaccination
• YF vaccination target groups
• Future market outlook

DENGUE

• Disease definition
• Etiology and transmission
• Disease progression and clinical manifestations
• Risk groups and factors
• Epidemiological overview
• The dengue epidemic is expanding on a global scale
• An epidemic in the US is now possible
• Current market overview
• Neither prophylaxis nor therapy is currently available
• Tetravalent vaccines protecting against all four dengue strains are undergoing development

MALARIA

• Disease definition
• Etiology and transmission
• Disease progression and clinical manifestations
• Epidemiological overview
• Malaria is a leading cause of death, especially among young children
• Childern under the age of five are the most important risk group
• Current market overview
• Despite the availability of curative therapy, vaccination is essential to contain the infection
• Resistance development limits the efficacy of existing antimalarial drugs
• Despite the challenges associated with the development of a malaria vaccine, several vaccine candidates are being developed
• Future market outlook

CASE STUDIES

• Lyme disease
• Disease overview
• Epidemiology
• Treatment and prevention
• Lymerix - lack of demand leads to vaccine withdrawal
• Issues abound from the beginning
• Safety fears cloud uptake and sales tail off after two years
• Rotavirus
• Disease overview
• Epidemiology
• Treatment
• Rotavirus vaccination - inauspicious beginnings but now a success?
• Three vaccines - enough potential?

APPENDIX A

• Sales channels and limitations of IMS data

APPENDIX B

• References
• Bibliography
• Journal articles
• Press releases
• Miscellaneous
• Disclaimer
• List of Tables
• Table 1: Estimated market potential for niche vaccines
• Table 2: Covered diseases: epidemiological facts
• Table 3: Smallpox disease progression
• Table 4: Smallpox was officially declared eradicated in 1980
• Table 5: Smallpox vaccination was officially stopped in 1986
• Table 6: Risks associated with current smallpox vaccinations
• Table 7: Key developmental smallpox vaccines based on attenuated viral strains
• Table 8: Incidence of cases of severe disease and deaths associated with West Nile virus infection in the US, 1999-2004
• Table 9: The West Nile virus vaccine pipeline consists of three candidates in Phase I
• Table 10: US population over the age of 50 years, 2005
• Table 11: Estimated market potential for the US West Nile fever market
• Table 12: Deaths caused by Japanese encephalitis in WHO member states, 1998-2002
• Table 13: Countries with past or present Japanese encephalitis epidemics
• Table 14: Japanese encephalitis JE-VAX vaccine: key facts
• Table 15: Yellow fever epidemiology: key facts
• Table 16: Clinical manifestations associated with dengue and dengue hemorrhagic fever (DHF)
• Table 17: Deaths caused by dengue fever in WHO member states, 1998-2002
• Table 18: Epidemiological comparison between Japanese encephalitis and dengue
• Table 19: The four malaria parasites differ in both geographical distribution and clinically
• Table 20: Deaths caused by malaria in WHO member states, 1998-2002
• Table 21: Deaths caused by three of the most deadly infectious and parasitic diseases, 2002
• Table 22: Marketed antimalarial drugs
• List of Figures
• Figure 1: Geographic distribution of the Japanese encephalitis serocomplex of the family Flaviviridae, 2000, Eastern Hemisphere
• Figure 2: West Nile virus activity in the US, 2004
• Figure 3: Global distribution of Japanese encephalitis, 2003
• Figure 4: Deaths caused by Japanese encephalitis infection by geographical area, 2003
• Figure 5: Estimated US & EU travelers JE vaccine market size, 2005
• Figure 6: Yellow fever disease progression
• Figure 7: Global distribution of yellow fever
• Figure 8: Global distribution of dengue fever, 2000
• Figure 9: Deaths caused by dengue virus infection by geographical area, 2003
• Figure 10: Global distribution of malaria
• Figure 11: Deaths caused by malaria by geographical area, 2003
• Figure 12: Distribution of Ixodes ticks that transmit Lyme disease in the US
• Figure 13: Lyme disease cases reported to the CDC by State Health Departments in the US, 1990-2002
• Figure 14: Average annual incidence of reported cases of Lyme disease, by age group and sex, in the US, 1992-1998
• Figure 15: Lymerix sales*, 1998-2003
• Figure 16: Global distribution of rotavirus strains
• Figure 17: Global distribution of rotavirus mortality
• Figure 18: Average time of peak rotavirus activity in the contiguous 48 states, US, July 1991 to June 1997
• Figure 19: Rotashield sales*, 1998-99
• Figure 20: Comparison of the three rotavirus vaccines
• Figure 21: Simplified schematic demonstrating vaccine supply channels to patients