Bell's palsy as a possible complication of mRNA-1273 (Moderna) vaccine against COVID-19.

Introduction: Vero Cell, AstraZeneca, Janssen, mRNA-1273 (Moderna), and Pfizer COVID-19 vaccines have been authorized for emergency use in Nepal. These vacines have been linked to some adverse effects, including fever, myalgia, and headache. Furthermore Bell's Palsy a rare adverse effect was also reported to be associated with the use of mRNA-1273 (Moderna) vaccine in some patients.

Case Presentation: In this case report we present a 17-year-old female who acquired Bell's Palsy following the administration of mRNA-1273 (Moderna) COVID-19 vaccination.

Discussion: The possible etiology of BP that has been suggested is infection by reactivated viruses, such as the varicella-zoster virus (VZV), herpes simplex virus type 1 (HSV-1), human herpesvirus 6, and the Usutu virus, [1] the most accepted hypothesis is the one with reactivation of latent Herpes Simplex Virus type 1 in the geniculate ganglia of the facial nerves, an autoimmune mechanism through the mimicry of host molecules by the antigens of the vaccines.

Conclusion: Though the extent of association between the mRNA vaccination and the development of Bell's Palsy has yet to be confirmed, this example highlights the need to closely monitor side effects and repercussions after receiving a new vaccine.