Could tattoos affect the protection we get from vaccines?
A new study – the first of its kind – suggests that tattoos could alter our body’s immune system and how well we fight off disease, including our vaccine response.
- 8 December 2025
- 4 min read
- by Priya Joi
Being tattooed can alter the way we respond to vaccines, dampening the protective effect from COVID-19 vaccines and dialling up the response to the flu vaccine, according to new research.
An international group of scientists, publishing last week in the Proceedings of the National Academy of Sciences, found that when the ink from a fresh tattoo fades, it doesn’t just wash off.
Instead it can drain into nearby lymph nodes, kill key immune cells and alter the response to some vaccines given in the same area – including COVID-19 and flu vaccines.
Tattoos are now mainstream: 37% of 35- to 54-year-olds in the UK now have at least one tattoo and the percentage is similar for the USA. The researchers warn that as tattooing becomes more common, a clearer understanding of how tattoo ink interacts with our immune cells and stricter toxicology testing and oversight of tattoo-ink ingredients is urgently needed.
Inflammatory changes
Researchers used experimental tattoos in mice to trace how commercial inks move through the body and interact with the immune system over time.
Within minutes of tattooing, pigments travelled along lymphatic vessels and accumulated in draining lymph nodes, where levels continued to rise over at least two months.
Microscopy and cell-marking techniques showed that the tattoo pigments were largely taken up by macrophages, the scavenger cells that normally help launch immune responses to vaccines and infections.
In both mouse experiments and tests on human immune cells in the lab, ink-laden macrophages were more likely to die and lymph nodes draining tattooed skin showed persistent inflammatory changes.
Vaccine responses
To test what this meant for vaccination, the team immunised mice with different vaccines either in tattooed skin draining to ink-filled lymph nodes or in non-tattooed areas.
When an mRNA-based COVID-19 vaccine was injected into a site whose lymph nodes were already loaded with pigment, antibody responses were reduced compared to controls. Expression of the SARS-CoV-2 viral spike protein in macrophages was also lower.
This spike protein is what primes our immune system to be able to fight off a COVID-19 infection, meaning that a reduced spike protein expression leads to reduced vaccine protection.
By contrast, responses to an inactivated influenza vaccine were in some cases enhanced, with black and especially red inks acting almost like an inflammatory adjuvant, depending on timing and ink colour.
These divergent effects suggest that tattoo-related inflammation and pigment overload may interfere with some vaccine platforms while boosting others, rather than exerting a uniform dampening effect.
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Human data
The researchers also analysed a small number of lymph node biopsies from people with tattoos, including samples taken up to two years after tattooing.
As in the mice, nodes were visibly stained with ink and packed with pigment-filled macrophages, alongside signs of chronic inflammation.
Although the study did not directly test vaccine responses in people, concerning links between tattoos and cancers have emerged in the past few years.
A Danish twin study published in January 2025 reported that people with tattoos had higher risks of skin cancers such as melanoma and squamous cell carcinoma, as well as lymphoma, and the risk rose in those with tattoos larger than a palm.
And in 2024, a Swedish study of almost 12,000 people found that people with tattoos had a 21% higher risk of malignant lymphoma than those who had not been inked.
The authors of this new study argue that, given the rapid global rise in tattooing, these changes deserve closer scrutiny in relation to infectious disease risks and vaccine performance.
For policymakers, they say, the immediate implication is not to change immunisation schedules, but to recognise tattooing as an environmental exposure that may need to be factored into future vaccine design, dosing strategies and site-of-injection guidance, particularly as new platforms such as mRNA are rolled out more widely.
The study authors conclude: “Considering the unstoppable trend of tattooing in the population, our results are crucial in informing the toxicology programs, policymakers, and the general public regarding the potential risk of the tattooing practice associated with an altered immune response.”
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