incomplete Bell's Palsy; acute onset right-sided facial weakness/right facial nerve paresis; nasolabial fold flattening drooping/drooping of the right corner of his mouth; enhancement of the tympanic and mastoid segments; This serious case was reported in a literature article and described the occurrence of bell's palsy in a 7-month-old male patient who received Flu Seasonal QIV Dresden (Influenza vaccine Quadrivalent unspecified season) for prophylaxis. Literature Reference:  Additional patient notes included no past medical history, did not take any medications or supplements routinely and had not traveled recently. Family history was negative for any neurological, bleeding or clotting disorders. Absence of erythema migrans by history. Concomitant products included Flu Seasonal QIV Dresden (Influenza vaccine Quadrivalent unspecified season).   On an unknown date, the patient received Influenza vaccine Quadrivalent unspecified season (intramuscular). On an unknown date, less than a week after receiving Influenza vaccine Quadrivalent unspecified season and an unknown time after receiving Influenza vaccine Quadrivalent unspecified season, the patient experienced bell's palsy (Verbatim: incomplete Bell's Palsy) (serious criteria hospitalization and GSK medically significant), facial weakness (Verbatim: acute onset right-sided facial weakness/right facial nerve paresis) (serious criteria hospitalization), decreased nasolabial fold (Verbatim: nasolabial fold flattening drooping/drooping of the right corner of his mouth) (serious criteria hospitalization) and facial asymmetry (Verbatim: enhancement of the tympanic and mastoid segments) (serious criteria hospitalization). The outcome of the bell's palsy, facial weakness, decreased nasolabial fold and facial asymmetry were resolved.   The reporter considered the bell's palsy, facial weakness, decreased nasolabial fold and facial asymmetry to be possibly related to Influenza vaccine Quadrivalent unspecified season.     The company considered the bell's palsy, facial weakness, decreased nasolabial fold and facial asymmetry to be possibly related to Influenza vaccine Quadrivalent unspecified season.   Additional Information: GSK Receipt Date: 3-Apr-2023 A previously healthy developmentally typical 7-month-old male patient presented to the emergency department with acute onset right-sided facial weakness that parents first noticed earlier in the morning. The patient's exam was notable for subtle right nasolabial fold flattening and drooping of the right corner of his mouth. The patient was able to close both eyelids completely and lift both eyebrows. Of note, the patient received initial intramuscular inactive quadrivalent influenza vaccine at 6-month well-child visit according to the Centers for Disease Control and Prevention (CDC) recommendations and had just received an appropriate booster dose of the intramuscular inactivated quadrivalent influenza vaccine 6 days prior to presentation. Magnetic resonance imaging (MRI) of the brain was performed due to concern for supranuclear involvement of the facial nerve in the setting of bilateral preserved forehead movements. The MRI demonstrated slight asymmetric increase in enhancement of the tympanic and mastoid segments of the right facial nerve. Labs were notable for a negative severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) polymerase chain reaction (PCR) and a negative serum herpes simplex virus (HSV) 1/2 PCR. The patient was not evaluated for Lyme disease, given the absence of erythema migrans by history and exam. The patient had no known exposure to any ticks, especially those from a Lyme endemic region. The patient was discharged home with a diagnosis of right facial nerve paresis. The patient was evaluated by both his pediatrician and a pediatric neurologist following discharge with complete resolution of his facial nerve paresis within 48 hours of symptom onset. The patient had not had further recurrence of symptoms even with continued yearly influenza immunizations and continues to grow and develop normally.  Although not conclusive, the close temporal association between his recent inactivated quadrivalent influenza vaccine and onset of facial nerve paresis suggested a possible underlying immunologic reaction. The author emphasized these studies only highlight a potential temporal association between immunizations and development of Bell's palsy; this did not mean the vaccines themselves caused Bell's palsy. This signal of a temporal association between influenza vaccine and Bell's palsy was much less clear in the pediatric population.