Study raises fresh concerns over rare autoimmune reaction following TD vaccine in adults

A newly published medical study has drawn attention to a potential link between the tetanus-diphtheria (Td) vaccine and a rare autoimmune disorder in adults, prompting renewed calls for deeper research into vaccine-related adverse events.

The study, published on January 16 in the peer-reviewed journal Cureus, documents the case of a previously healthy 48-year-old woman who developed immune thrombocytopenia (ITP) one week after receiving a Td booster shot following a traumatic injury at home.

The woman required two hospitalizations within a month to manage the condition, which the authors identified as a vaccine-related injury.

ITP is a rare disorder in which the immune system mistakenly attacks and destroys platelets—cells essential for blood clotting. The condition can lead to excessive bruising, spontaneous bleeding, and, in severe cases, life-threatening hemorrhage.

“ITP occurs when the immune system is tricked into seeing platelets as a foreign invader and destroys them,” said Karl Jablonowski, Ph.D., senior research scientist at Children’s Health Defense (CHD). “Platelets are how we stop from bleeding, and there is no redundant backup if we don’t have them.”

While previous research has shown that Td vaccines may, in extremely rare cases, trigger ITP—primarily in children—the Cureus study highlights the lack of data involving adults.

The authors cautioned clinicians to remain alert, describing ITP as “a very rare but potentially life-threatening adverse reaction.”

The Td vaccine is routinely administered as a booster every 10 years for adolescents and adults and is commonly given after injuries that pose a risk of tetanus infection.

According to the study, the patient had an otherwise unremarkable medical history and had never received a Td vaccine prior to the incident. After sustaining an injury, she underwent surgery and was given the Td vaccine the following day.

One week later, she developed severe thrombocytopenia, petechiae—small spots of bleeding on the skin—and symptoms of tachycardia, or elevated heart rate.

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Extensive testing ruled out other possible causes, and the woman’s condition gradually improved after three to four weeks of treatment.

The researchers concluded that the case underscores the diagnostic and therapeutic challenges of ITP in adults and highlights the need for more comprehensive research into a possible causal relationship between the Td vaccine and ITP in this age group. They noted that only two published studies to date have examined this association in adults.

“Vaccine-induced ITP from the Td booster shot is a well-documented phenomenon in children yet rare among adults,” the authors wrote.

The study also situates Td-related ITP within a broader context of vaccine-associated thrombocytopenia. Several other vaccines—including influenza, hepatitis B, herpes zoster, and the Pfizer-BioNTech and Moderna mRNA COVID-19 vaccines—have been linked to cases of ITP.

Meanwhile, non-mRNA adenoviral COVID-19 vaccines, such as Johnson & Johnson (Janssen) and AstraZeneca, have been associated with a related but distinct condition known as thrombotic thrombocytopenia, which involves dangerous blood clots forming in small vessels.

“ITP can be triggered by any vaccine,” Jablonowski said. “The immune system is incredibly complex. Every vaccine interacts with that system in ways we cannot fully predict or control.”

Barbara Loe Fisher, co-founder and president of the National Vaccine Information Center, said the study highlights significant gaps in scientific understanding of vaccine-induced immune dysfunction.

“It points out the shocking gaps in foundational scientific knowledge about the biological mechanisms of vaccine-induced immune dysfunction that can cause serious health outcomes like thrombocytopenia,” Fisher said.

She added that limited research into vaccine safety reflects a broader failure by the scientific and medical establishment to prioritize investigations into vaccine injuries.

Fisher also cited reports issued in 1991, 1994 and 2012 by the Institute of Medicine—now the National Academy of Medicine—warning of potential links between certain vaccines and thrombocytopenia.

According to the Cureus authors, the lack of adult-focused studies means the biological mechanisms behind Td-related ITP remain poorly understood. They suggested that molecular mimicry, genetic susceptibility, and environmental or clinical factors may play a role.

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Jablonowski offered a possible explanation, suggesting that antibodies produced in response to vaccination may mistakenly bind to a person’s own platelets, marking them for destruction by the immune system.

The researchers also referenced earlier peer-reviewed evidence, including a 2011 study published in Vaccine documenting a 15-month-old child who developed ITP after receiving measles-rubella, varicella, and mumps vaccines. In that case, vaccine-related antibodies were found bound to the child’s platelets months after symptom onset, supporting the idea that vaccine-induced ITP involves a distinct immunological mechanism.

Brian Hooker, Ph.D., CHD’s chief scientific officer, compared the 48-year-old woman’s case to that of Alexis Lorenze, who experienced severe autoimmune reactions after being required to receive multiple vaccines—including a tetanus shot—prior to a blood transfusion for paroxysmal nocturnal hemoglobinuria, another rare autoimmune disorder.

Meanwhile, concerns about thrombocytopenia have intensified in recent years. Jablonowski noted that reports of thrombocytopenia submitted to the U.S. Vaccine Adverse Event Reporting System (VAERS) surged in 2021, the first year COVID-19 vaccines were widely distributed, reaching numbers nearly equivalent to the total reports filed over the previous two decades combined.