Diseases and vaccines

Japanese encephalitis vaccine safety and efficacy

Live, attenuated SA 14-14-2 JE vaccine

Effect of single dose of SA 14-14-2 vaccine 1 year after immunisation in Nepalese children with Japanese encephalitis: a case-control study (2005; abstract only)
Ohrr, et al. Lancet. 366(9494):1375-8.
Investigators conducted a case-control study and efficacy of the SA 14-14-2 JE vaccine to be 98.5 percent 12 to 15 months after vaccination.

Long-term immunogenicity of measles vaccine after coadministration with live attenuated Japanese encephalitis vaccine (2007)
Gatchalian S, et al.
This follow-up study to PATH's original coadministration trial (see below) demonstrated that measles seroprotection rates were still high one year post-vaccination among infants who originally seroconverted for measles.

Measles vaccine immunogenicity after coadministration with live attenuated Japanese encephalitis vaccine shows equivalence to that of measles vaccine given alone (2006)
Gatchalian S, et al.
This study by PATH's JE project determined that measles vaccine and the live, attenuated JE vaccine can be safely co-administered with no effect on the immunogenicity of either.

Protection of SA 14-14-2 live attenuated Japanese encephalitis vaccine against the wild-type JE viruses (2003)
Jia L, Wang Z, Yu Y. Chinese Medical Journal. 116(6):941-943.
This study found the SA 14-14-2 vaccine to be broadly immunogenic and protective against several strains of JE endemic to Asia.

Short-term safety of live attenuated Japanese encephalitis vaccine (SA 14-14-2): Results of a randomized trial with 26,239 subjects (1997)
Liu, et al. Journal of Infectious Diseases. 176(5):1366-1369.
This study evaluated the occurrence of severe adverse events among children immunized with the live, attenuated SA 14-14-2 JE vaccine for 30 days, and data demonstrated short-term safety of the vaccine.

Single dose of SA 14-14-2 vaccine provides long-term protection against Japanese encephalitis: a case-control study in Nepalese children 5 years after immunization (2007; abstract only)
Tandan J, et al. Vaccine. 25(27):5041-5.
Returning to Nepali villages where they conducted a case control study that revealed 99 percent efficacy after one year among children who received a single dose of the vaccine, investigators found that protection extended through five years with an efficacy of 96 percent.

Inactivated, mouse brain-derived JE vaccine

An assessment of the interval between booster doses of Japanese encephalitis vaccine in the Torres Strait (2005)
Hanna J, et al. Australian and New Zealand Journal of Public Health. 29(1):44-47.
This study found low levels of protective antibodies among adults and children 30 to 36 months after they had received either a previous booster or had completed the primary immunization series. The authors call for a safer and more immunogenic JE vaccine.

Japanese encephalitis vaccine (inactivated, BIKEN) in US soldiers: Immunogenicity and safety of vaccine administered in two dosing regimens (1999)
Defraites, et al. American Journal of Tropical Medicine and Hygiene. 61(2):288-293.
Investigators found that three doses provided at 0, 7, and 30 days resulted in higher antibody titers than a dosing schedule of 0, 7, and 14 days.

Protection against Japanese encephalitis by inactivated vaccines (1988; abstract only)
Hoke, et al. New England Journal of Medicine. 319(10):608-614
This evaluation of two doses of monovalent and bivalent inactivated mouse brain-derived JE vaccines in a northern Thai province found a combined rate of 91% efficacy.

JE vaccines in development

Safety and immunogenicity of a Vero-cell-derived, inactivated Japanese encephalitis vaccine: a non-inferiority, phase III, randomised controlled trial (2007; abstract only)
Tauber E, et al. Lancet. 370:1847-1853.
This study demonstrated a strong immunogenicity and safety profile among adults for a JE vaccine under development by Intercell.