Annette
                    
                    
                    
                    
                    
                    
                    
                        
                        
                        Hello Lynn: been researching that myself  seems it depends on the type you had. Herpes encephalitis can reoccur at times, the ones caused by insects don't seem to. Unknown viruses they don't know hopefully they will someday. anything else I can help you with please let me know  e-mail is dapeatons@juno.com