From the Guidelines
There is no established link between COVID-19 vaccines and salivary gland tumors, and COVID-19 vaccines are considered safe and effective for individuals with salivary gland tumors. The most recent and highest quality study, published in 2024 in the Journal of Clinical Oncology 1, found that COVID-19 vaccines protect patients with cancer, reducing the risk of severe COVID-19 illness and hospitalization. Some people may experience temporary lymph node swelling after vaccination, including nodes near the salivary glands, but this is a normal immune response and typically resolves within days to weeks, as noted in the 2024 ASCO guideline 1. This swelling should not be confused with tumor development. If you notice a persistent lump or swelling in your salivary gland area, you should consult a healthcare provider for proper evaluation, regardless of vaccination status. Key points to consider include:
- The benefits of COVID-19 vaccination in preventing severe illness, hospitalization, and death from COVID-19 far outweigh any theoretical concerns about salivary gland issues, as supported by the 2024 study 1.
- Standard COVID-19 vaccine recommendations apply to individuals with salivary gland tumors, though those undergoing active cancer treatment should discuss timing with their oncologist, as recommended in the 2024 ASCO guideline 1.
- The most current recommendation for previously COVID-19–vaccinated individuals is to receive at least one dose of the updated 2023-2024 COVID-19 vaccine (any authorized formulation), according to the 2024 ASCO guideline 1.
From the Research
Relationship Between Salivary Gland Tumors and COVID-19 Vaccine
- There is evidence to suggest that COVID-19 vaccination may stimulate anticancer immunity and tumor regression in patients with salivary gland tumors 2.
- A case study reported spontaneous regression of metastatic salivary gland myoepithelial carcinoma in a patient who experienced grade 3 systemic reactogenicity following vaccination with the mRNA-1273 COVID-19 vaccine 2.
- The study found that the postvaccination lung metastasis samples had remarkable immune cell infiltration, including CD4+ T cells, CD8+ T cells, natural killer cells, B cells, and dendritic cells, which contrasted with very low levels of these cells in the prevaccination primary tumor and lung metastasis samples 2.
Salivary Immune Responses After COVID-19 Vaccination
- mRNA-based COVID-19 vaccines have been shown to elicit salivary immune responses, with SARS-CoV-2-specific antibodies detectable in saliva after vaccination 3, 4.
- The salivary immune response after vaccination with the COVID-19 Moderna mRNA-1273 vaccine was evaluated in a study, which found that SARS-CoV-2-specific salivary IgA titers peaked 2 weeks after each vaccine dose, followed by a sharp decrease during the following weeks 3.
- Another study found that the mRNA BNT162b2 COVID-19 vaccine determines the production of nasal and salivary IgA-S1 and IgG-RBD against SARS-CoV-2, with a stronger mucosal humoral immune response after the second vaccine dose compared to subjects recovered from COVID-19 4.
Oral Adverse Events Following COVID-19 Vaccination
- Oral adverse events (AEs) following COVID-19 vaccination have been reported, including oral paresthesia, swelling of lips, ageusia, oral hypoesthesia, swollen tongue, and dysgeusia 5.
- A retrospective analysis using the Vaccine Adverse Event Reporting System (VAERS) data found that the reported prevalence of oral AEs was higher in the COVID-19 vaccine group than in the seasonal influenza group 5.
- The distribution pattern of the most reported oral AEs was similar for both COVID-19 and seasonal influenza vaccines, with female sex, older age (>39 years old), primer doses, and mRNA-based COVID-19 vaccines exhibiting a higher reported prevalence of oral AEs 5.