Oral manifestations after vaccinations: A systematic review of observational studies

Objective: This study aimed to assess the prevalence and types of oral adverse events following immunization (AEFIs) in people who received at least one dose of any type of vaccine. Materials and methods: We conducted a bibliographic search about oral AEFIs in MEDLINE, Embase, PubMed, and Ovid from database inception to November 07, 2022. Risk of bias was assessed using the MURAD or the Quality In Prognosis Studies tools. Random-effects proportional meta-analysis was applied. Results: A total of 119 studies involving 343 people were eligible. These reported AEFIs occurred following administration of the coronavirus disease 2019 vaccine, anti-influenza vaccine, hepatitis B vaccine, and anti-smallpox vaccine. The most common to be affected in vaccinated people were buccal mucosa (63.1%; 95% confidence interval (CI) 33.4-88.2) and lips (55.7%; 95% CI, 41.1-69.8). The most prevalent oral AEFIs were ulceration (55.2%; 95% CI 24.4-84.0), swelling (65.2%; 95% CI 34.9-89.8), and burning sensation (18.3%; 95% CI 7.9-31.8). Conclusions: The mechanisms underlying oral AEFIs should be further investigated to promptly recognize oral manifestations and provide optimal management for people undergoing vaccination.