A novel amino acid site closely associated with the neurovirulence of live, attenuated Japanese encephalitis vaccine (SA14-14-2 strain).

In this study, we introduced a single mutation at nt1708 (G → A) in the full-length cDNA clone of SA14-14-2, replacing a Gly with Glu at amino acid residue 244 of the E glycoprotein, and successfully constructed the mutant virus (JEV E244). JEV E244 exhibited a similar plaque morphology and growth characteristics to JEV SA14-14-2 in cell culture. However, it had lethal neurovirulence in mice and could enter the brain following intraperitoneal inoculation. Moreover, the virulence of JEV E244 in the context of vaccine in mice is significantly different from that of the JEV E244 alone. These results suggested that E244 site should be included in the assessment of the genetic stability of the attenuated JE vaccine. The detection of minor mutations in vaccine population and influence on the safety of vaccine is discussed.
PMID: 32044162 [PubMed - as supplied by publisher]

Source: Vaccine - February 6, 2020 Category: Allergy & Immunology Authors: Yang H, Fan F, Liu L, Liu J, Sun Y, Xie A, Shi X, Liu L, Yu Y, Li Y, Ge Y, Zeng X, Yang H Tags: Vaccine Source Type: research