Antigenic characterization of the live attenuated Japanese encephalitis vaccine virus SA14-14-2: a comparison with isolates of the virus covering a wide geographic area

Mark R. Wills, Bijon K. Sil, Jing X. Cao, Y. X. Yu, Alan Barrett

Research output: Contribution to journalArticle

35 Scopus citations


In China, a live attenuated Japanese encephalitis (JE) vaccine, based on strain SA14-14-2, has been derived from the wild-type strain SA14 as an alternative to the current inactivated vaccines such as Nakayama-NIH and P-3. SA14-14-2 has been characterized using monoclonal antibodies derived in mice, using HAI and neutralization tests, and compared with other Chinese live vaccine clones and 14 wild-type strains of JE virus. Wild-type strain SA14 was found to be a poor immunogen and antigenically distant from all other viruses examined. The vaccine derivatives SA14-5-3 was more immunogenic than its wild-type parent, while SA14-14-2 (derived from SA14-5-3) was more immunogenic than SA14-5-3 and elicited a cross neutralizing antibody response. Our studies indicated that JE virus strain Nakayama elicited as good a neutralizing antibody response in hyperimmunized mice as the SA14-14-2 vaccine clones grown in either primary hamster kidney (PHK) or primary dog kidney (PDK) cells. A single dose of live SA14-14-2 (PHK) also elicited a good antibody response. Antigenic variation between wild-type and vaccine clones of JE virus were detected but were not considered significant in terms of controlling JE virus infections by vaccination.

Original languageEnglish (US)
Pages (from-to)861-872
Number of pages12
Issue number12
StatePublished - 1992
Externally publishedYes



  • Immunogenicity
  • Japanese encephalitis
  • vaccine

ASJC Scopus subject areas

  • Immunology
  • Microbiology
  • Virology
  • Infectious Diseases
  • Public Health, Environmental and Occupational Health
  • veterinary(all)

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