A new study has revealed that tattoo ink can travel to lymph nodes and cause lifelong changes to the body’s immune system, potentially affecting vaccine responses. The research, published in the Proceedings of the National Academy of Sciences, is the first to explore the impact of tattoo ink on immune responses.
Using mice, scientists observed that ink from tattoos on the hind feet moved along lymphatic vessels to nearby lymph nodes within minutes. The ink accumulated in the nodes, leading to chronic inflammation, death of macrophages (a type of white blood cell), and altered immune responses to vaccinations.
The study found that the ink affected responses to vaccines differently: it reduced the response to the Covid-19 vaccine but enhanced the response to an UV-inactivated influenza vaccine. The researchers noted that the ink remains in the lymph nodes for a lifetime, even if the tattoo is removed.
“This work represents the most extensive study to date regarding the effect of tattoo ink on the immune response and raises serious health concerns associated with the tattooing practice,” the team said, noting that at least one in five people globally has a tattoo.
The findings underscore the need for further research to inform public health policies and regulatory frameworks on tattoo ink safety. Previous studies have linked tattoos to an increased risk of lymphoma, with a BMC Public Health study suggesting the risk could be three times higher for people with large tattoos.
