From the Guidelines
Allergic reactions to the Tdap vaccine are rare, with severe allergic reactions, such as anaphylaxis, occurring in approximately 1 in a million doses, as reported in the most recent guidelines 1. The frequency of allergic reactions to Tdap vaccine is a critical consideration in vaccination decisions.
- The most recent and highest quality study, published in 2018, provides guidelines for vaccine use and reports that severe allergic reactions are rare 1.
- According to these guidelines, contraindications for Tdap vaccine include a history of severe allergic reaction to a previous dose or to a vaccine component, and precautions should be taken in cases of progressive or unstable neurologic disorder, uncontrolled seizures, or progressive encephalopathy.
- The guidelines also note that the benefits of vaccination generally far outweigh the minimal risk of allergic reaction for most individuals, and that people with a history of severe allergic reaction to a previous dose of Tdap or any of its components should not receive the vaccine 1.
- Common side effects of the Tdap vaccine include pain, redness, or swelling at the injection site, mild fever, headache, fatigue, and muscle aches, which typically resolve within a few days.
- It is essential to inform healthcare providers about any previous reactions to vaccines before receiving Tdap, and to weigh the benefits and risks of vaccination on a case-by-case basis, particularly in individuals with underlying medical conditions 1.
From the Research
Allergic Reactions to Tdap Vaccine
- The frequency of allergic reactions to vaccines, including Tdap, is rare, with anaphylactic reactions occurring in fewer than 1 in a million doses administered 2.
- Allergic reactions to vaccines are most often due to vaccine constituents rather than the microbial components of the vaccine 3.
- The reaction rate per each dose of vaccine is low, but this is a common clinical question due to the large numbers of vaccines administered 3.
Frequency of Allergic Reactions
- Vaccine-related confirmed allergic reactions are rare in children, ranging between 0.65-1.45 cases per million vaccine doses 4.
- Anaphylactic reaction to vaccinations is rare and is estimated to occur at a rate of 1 per million doses 5.
- Immediate hypersensitivity reactions to vaccines, including anaphylaxis, are uncommon events occurring in fewer than 1 in a million doses administered 2.
Management of Allergic Reactions
- Evaluation of patients with suspected vaccine reactions should begin by determining whether the symptoms and timing of the reaction were consistent with a true allergic reaction 3.
- Skin and serologic testing to vaccines and vaccine constituents can be performed to further assess the potential cause of the reaction and to develop a plan for future immunizations 3.
- If needed, skin tests with the relevant vaccines and administration of vaccines in graded doses under supervision and preparation for treatment of the anaphylactic reaction in the Allergy clinic, can ensure the effective completion of childhood immunizations 5.