COVID-19 vaccines and oral symptoms

Fraser Macdonald, Dental Tribune International

Wed. 4. February 2026

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BRNO, Czech Republic: Reports of oral symptoms after COVID-19 vaccination have recently re-entered online debate after the publication of a pharmacovigilance study analysing safety reports submitted to the Paul-Ehrlich-Institut (PEI), an agency of the German Federal Ministry of Health. The study examined nearly one million individual case safety reports, offering one of the most comprehensive overviews to date of oral complaints recorded after vaccination in Germany. Its findings were cautious in interpretation and presented as part of routine safety monitoring by European regulators. However, the study has since been reframed by some anti-vaccine and vaccine-sceptical platforms as evidence that COVID-19 vaccines cause oral disease—even though the study does not assess causality.

The study, undertaken by Dr Abanoub Riad, associate professor in the Department of Public Health at Masaryk University in Brno, summarised patterns in oral adverse events reported after COVID-19 vaccination and used standard pharmacovigilance methods to identify oral events that appeared unusually often in the safety report database after vaccination. These methods are routinely used by regulators as an early alert system to spot whether a specific drug–event combination appears more frequently than would be expected within a database. In this case, the dominant pattern identified was sensory oral complaints.Taste disturbances, including ageusia and dysgeusia, accounted for the largest share of reports, alongside other sensory symptoms such as oral paraesthesia and hypaesthesia. A smaller but clinically relevant proportion of reports included mucosal symptoms such as aphthous stomatitis and oral herpes, as well as orofacial swelling affecting the lips and tongue. These patterns represent what was most frequently recorded within the German passive surveillance system, not the actual frequency of such symptoms within the vaccinated population.

“It is important to emphasise that COVID-19 vaccines remain highly safe and effective.”

Talking about any possible relationship between COVID-19 vaccination and disruptions to oral health, Dr Riad stated: “It is important to emphasise that COVID-19 vaccines remain highly safe and effective. The oral events identified in this study were overwhelmingly non-serious, non-life-threatening and frequently transient. Some may be noticeable or uncomfortable for patients and can temporarily affect oral comfort or function. From a public health perspective, recognising and monitoring such events within routine vaccine and drug safety systems supports transparency, informed patient counselling and clinical reassurance—without undermining the well-established overall safety of COVID-19 vaccines.”

Dr Abanoub Riad argues that anti-vaccination groups have fundamentally misinterpreted the core findings of his study into the links between oral health and COVID-19 vaccination. (Image: Dr Abanoub Riad)

A crucial distinction made by the author is that unusual reporting patterns flagged in the database do not equate to evidence of causal harm. In pharmacovigilance, identifying such a pattern is the first step in a longer regulatory review process, which proceeds through validation, confirmation, analysis and prioritisation before any regulatory action can even be considered. The study therefore represents the very beginning of routine safety monitoring, not its conclusion. Moreover, because the majority of oral symptoms reported were non-serious, transient and non-life-threatening and because COVID-19 vaccines continue to demonstrate a favourable safety and benefit profile, even in a hypothetical scenario in which a causal link to vaccination were confirmed, the appropriate response would be to inform recipients rather than restrict use, much as clinicians already do for dermatological reactions.

Even so, some anti-vaccine and vaccine-sceptical commentary has reframed the study findings as evidence that COVID-19 vaccines cause oral disease. A post by the website and newsletter Focal Points—shared by its author on X—presented the PEI reporting data as indicating that COVID-19 vaccination is linked to oral pathology, implying a causal relationship and suggesting that such outcomes are occurring at meaningful scale. The Swedish website TF.nu too stated that COVID-19 vaccinations are connected to oral discomfort, again implying causality and overlooking the methodological limitations of passive surveillance data.

These misrepresentations rely on two errors. The first is to convert a preliminary pattern into a claim of causal harm. Passive surveillance systems such as the PEI’s are not incidence registries and do not establish whether a vaccine caused an event; they simply flag patterns worthy of further examination. Temporality alone—an event happening after vaccination—cannot establish causation. The second error involves misunderstanding the absolute reporting ratio used in the study. The absolute reporting ratio reflects how frequently a particular oral complaint appeared per 1,000 COVID-19 vaccine safety reports, not per vaccinated person or per administered dose in the population. Conflating absolute reporting ratio with incidence inflates reporting patterns into epidemiological claims the data cannot support. It is therefore scientifically incorrect to attribute these events to vaccines on this basis alone.

The consequences of such misinterpretations are not merely academic. They risk eroding public trust in vaccines by suggesting that routine vaccine safety monitoring after approval has uncovered harms that regulators are ignoring. On this crucial point, Dr Riad explained: “Such misinterpretations are dangerous because they transform early safety signals into claims of harm that the data cannot support, thereby undermining public trust in vaccines with a well-established favourable benefit–risk profile. Such distortions can fuel vaccine hesitancy or refusal, not because of new scientific evidence, but because of the misrepresentation of surveillance data that was never intended to support causal claims.”

“Such misinterpretations are dangerous because they transform early safety signals into claims of harm that the data cannot support.”

These interpretive distortions also create challenges in clinical communication. Dentists and other healthcare professionals may encounter anxious patients who attribute common transient oral symptoms to COVID-19 vaccination and overestimate their clinical significance, prompting unnecessary investigations or referrals. Furthermore, the integrity of pharmacovigilance systems themselves is jeopardised. If surveillance data is routinely reframed as proof of hidden harm, there is a risk of both under-reporting driven by distrust and over-reporting fuelled by publicity or fear. This weakens the ability of regulators and researchers to prioritise genuine safety issues and take proportionate, evidence-based action.

For dental professionals, the key message is not that COVID-19 vaccines are damaging oral health but that oral symptoms occasionally appear in safety reporting systems and are overwhelmingly mild and temporary. Recognising and contextualising such events allows clinicians to reassure patients accurately, contribute to balanced surveillance and help counter online narratives that distort findings on early safety monitoring into claims of confirmed harm.

The article, titled “National pharmacovigilance assessment of oral adverse events following COVID-19 vaccination in Germany (2020-2023)”, was published in the October 2025 issue of the International Dental Journal.