This article was downloaded by: [University of Pennsylvania] On: 04 September 2015, At: 06:48 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London, SW1P 1WG
Expert Review of Vaccines Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ierv20
The Vero cell-derived, inactivated, SA14-14-2 strainbased vaccine (Ixiaro) for prevention of Japanese encephalitis ab
Elina O Erra
bc
& Anu Kantele
a 1
Haartman Institute, University of Helsinki, Helsinki, Finland
b 2
Inflammation Center, Clinic of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland c 3
Unit of Infectious Diseases, Department of Medicine/Solna, Karolinska Institutet, Stockholm, Sweden Published online: 10 Jul 2015.
Click for updates To cite this article: Elina O Erra & Anu Kantele (2015) The Vero cell-derived, inactivated, SA14-14-2 strainbased vaccine (Ixiaro) for prevention of Japanese encephalitis, Expert Review of Vaccines, 14:9, 1167-1179, DOI: 10.1586/14760584.2015.1061939 To link to this article: http://dx.doi.org/10.1586/14760584.2015.1061939
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Downloaded by [University of Pennsylvania] at 06:48 04 September 2015
Vaccine Profile
The Vero cell-derived, inactivated, SA14-14-2 strain-based vaccine (Ixiaro) for prevention of Japanese encephalitis Expert Rev. Vaccines 14(9), 1167–1179 (2015)
Elina O Erra*1,2 and Anu Kantele2,3 1 Haartman Institute, University of Helsinki, Helsinki, Finland 2 Inflammation Center, Clinic of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland 3 Unit of Infectious Diseases, Department of Medicine/Solna, Karolinska Institutet, Stockholm, Sweden *Author for correspondence: Tel.: +35 894 711 [email protected]
With an estimated 68,000 cases each year, Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Vaccination against the disease is recommended for endemic populations and also for travelers at risk. Recently, a Vero cell-derived, inactivated, SA14-14-2 strain-based JE vaccine (JE-VC) became available for travelers from non-endemic regions, replacing the traditional mouse brain-derived vaccines. First licensed in 2009, JE-VC is currently available in Europe, the USA, Canada, Australia and several other countries. In 2013, the vaccine was approved by the European Medicines Agency and the US Food and Drug Administration for use in children. This review summarizes current data on the immunogenicity, safety and clinical use of JE-VC. KEYWORDS: immunogenicity . Ixiaro . Japanese encephalitis . JE-VC . Japanese encephalitis vaccine . safety . traveler
Japanese encephalitis (JE) is considered the leading cause of viral encephalitis in Asia [1]. According to estimates, JE causes annually approximately 68,000 cases, of which 14,300– 27,200 lead to long-term disability and 13,600–20,400 to death [2].
birds are the main vertebrate hosts of the virus. Humans are considered as dead-end hosts: they acquire the infection through the bite of a vector mosquito, and the virus is usually not transmitted further because the viremia tends to be only transient and at a low level.
Etiology
The causative agent of JE, Japanese encephalitis virus (JEV), is a mosquito-borne flavivirus (genus Flavivirus, family Flaviviridae). Like other flaviviruses, JEV has a single-strand positive-sense RNA genome encoding seven nonstructural and three structural proteins, of which the envelope protein is considered the major target of the neutralizing antibody response [3]. Five phylogenetically distinct genotypes of JEV have been recognized (GI–GV) [4]. The restricted divergence of the envelope proteins suggests that all JEV genotypes belong to a single serotype [5]. Transmission
JEV is transmitted by mosquitoes, primarily in rural agricultural settings [6]. Pigs and wading informahealthcare.com
10.1586/14760584.2015.1061939
Epidemiology
JE is endemic or epidemic in large areas of Asia and parts of the Western Pacific, with China and India reporting the majority of cases [1]. Two epidemiological transmission patterns have been recognized. Northern temperate areas experience epidemics during the summer months, whereas in southern tropical regions, transmission occurs year-round, with peaks after the onset of the rainy season [7]. For decades, GIII was the most frequently isolated JEV genotype. Recently, however, emergence of GI has been reported in many endemic regions [8–13]. The other three genotypes (GII, GIV, GV) appear to be of minor clinical significance at the moment. Investigations of mosquito pools in China and South
2015 Informa UK Ltd
ISSN 1476-0584
1167
Vaccine Profile
Erra & Kantele
Table 1. Summary of published cases of JE among travelers or expatriates from non-endemic regions, 1973–2014. Median
Range
35
(1–91)
%
n
Male
58%
36/62
Female
42%
26/62
Thailand
35%
22/63
Indonesia
14%
9/63
Vaccination recommendations
China
13%
8/63
The Philippines
11%
7/63
Japan
6%
4/63
Vietnam
5%
3/63
South Korea
3%
2/63
13%
8/63
‡4 weeks
63%
31/49
Expert Review of Vaccines Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ierv20
The Vero cell-derived, inactivated, SA14-14-2 strainbased vaccine (Ixiaro) for prevention of Japanese encephalitis ab
Elina O Erra
bc
& Anu Kantele
a 1
Haartman Institute, University of Helsinki, Helsinki, Finland
b 2
Inflammation Center, Clinic of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland c 3
Unit of Infectious Diseases, Department of Medicine/Solna, Karolinska Institutet, Stockholm, Sweden Published online: 10 Jul 2015.
Click for updates To cite this article: Elina O Erra & Anu Kantele (2015) The Vero cell-derived, inactivated, SA14-14-2 strainbased vaccine (Ixiaro) for prevention of Japanese encephalitis, Expert Review of Vaccines, 14:9, 1167-1179, DOI: 10.1586/14760584.2015.1061939 To link to this article: http://dx.doi.org/10.1586/14760584.2015.1061939
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Downloaded by [University of Pennsylvania] at 06:48 04 September 2015
Vaccine Profile
The Vero cell-derived, inactivated, SA14-14-2 strain-based vaccine (Ixiaro) for prevention of Japanese encephalitis Expert Rev. Vaccines 14(9), 1167–1179 (2015)
Elina O Erra*1,2 and Anu Kantele2,3 1 Haartman Institute, University of Helsinki, Helsinki, Finland 2 Inflammation Center, Clinic of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland 3 Unit of Infectious Diseases, Department of Medicine/Solna, Karolinska Institutet, Stockholm, Sweden *Author for correspondence: Tel.: +35 894 711 [email protected]
With an estimated 68,000 cases each year, Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Vaccination against the disease is recommended for endemic populations and also for travelers at risk. Recently, a Vero cell-derived, inactivated, SA14-14-2 strain-based JE vaccine (JE-VC) became available for travelers from non-endemic regions, replacing the traditional mouse brain-derived vaccines. First licensed in 2009, JE-VC is currently available in Europe, the USA, Canada, Australia and several other countries. In 2013, the vaccine was approved by the European Medicines Agency and the US Food and Drug Administration for use in children. This review summarizes current data on the immunogenicity, safety and clinical use of JE-VC. KEYWORDS: immunogenicity . Ixiaro . Japanese encephalitis . JE-VC . Japanese encephalitis vaccine . safety . traveler
Japanese encephalitis (JE) is considered the leading cause of viral encephalitis in Asia [1]. According to estimates, JE causes annually approximately 68,000 cases, of which 14,300– 27,200 lead to long-term disability and 13,600–20,400 to death [2].
birds are the main vertebrate hosts of the virus. Humans are considered as dead-end hosts: they acquire the infection through the bite of a vector mosquito, and the virus is usually not transmitted further because the viremia tends to be only transient and at a low level.
Etiology
The causative agent of JE, Japanese encephalitis virus (JEV), is a mosquito-borne flavivirus (genus Flavivirus, family Flaviviridae). Like other flaviviruses, JEV has a single-strand positive-sense RNA genome encoding seven nonstructural and three structural proteins, of which the envelope protein is considered the major target of the neutralizing antibody response [3]. Five phylogenetically distinct genotypes of JEV have been recognized (GI–GV) [4]. The restricted divergence of the envelope proteins suggests that all JEV genotypes belong to a single serotype [5]. Transmission
JEV is transmitted by mosquitoes, primarily in rural agricultural settings [6]. Pigs and wading informahealthcare.com
10.1586/14760584.2015.1061939
Epidemiology
JE is endemic or epidemic in large areas of Asia and parts of the Western Pacific, with China and India reporting the majority of cases [1]. Two epidemiological transmission patterns have been recognized. Northern temperate areas experience epidemics during the summer months, whereas in southern tropical regions, transmission occurs year-round, with peaks after the onset of the rainy season [7]. For decades, GIII was the most frequently isolated JEV genotype. Recently, however, emergence of GI has been reported in many endemic regions [8–13]. The other three genotypes (GII, GIV, GV) appear to be of minor clinical significance at the moment. Investigations of mosquito pools in China and South
2015 Informa UK Ltd
ISSN 1476-0584
1167
Vaccine Profile
Erra & Kantele
Table 1. Summary of published cases of JE among travelers or expatriates from non-endemic regions, 1973–2014. Median
Range
35
(1–91)
%
n
Male
58%
36/62
Female
42%
26/62
Thailand
35%
22/63
Indonesia
14%
9/63
Vaccination recommendations
China
13%
8/63
The Philippines
11%
7/63
Japan
6%
4/63
Vietnam
5%
3/63
South Korea
3%
2/63
13%
8/63
‡4 weeks
63%
31/49
