I got that same smile soon(!) after a Shingles "vaxx" several years ago. Was told it could last several weeks, several months, several years OR lifetime---oooo almost forgot the physician DENIED my problem came from "vaxx"--sent me for EXPENSIVE test after test to see if I had a stroke--NO sign of stroke or other problems. Physician STILL said there is NO WAY it could have been related--timing was coincidental.....
Thanks to God I only suffered with it for several weeks. I know people who still have it...