Vaccine allergy: the true of the false | The doctor’s daily life | Specialties

After vaccination. Meanwhile, immediate IgE-Médie-type allergies are extremely rare (1 to 10 cases for 1,000,000 doses), according to recent studies on numerous vaccines (flu, hepatitis B, HPV, SARS-COV-2 …). Therefore, But post -vaccinal clinical manifestations can. Furthermore, for some patients, evoke an allergy: local reactions and nonaphylactic, immediate or delayed systemic reactions are frequently observed.

Systemic vasovagal reactions – Vaccine allergy: true false |

The main manifestations of an immediate systemic reaction are fever. Nevertheless, fatigue, headaches, hives, rashes, a possible vasovagal reaction (bradycardia, hypotension, etc.) or a reaction linked to anxiety (dyspnea, etc.). Therefore, « This is how it is necessary to clearly distinguish an anaphylactic reaction. Nevertheless, which generally occurs in the 30 minutes (whistles, stridor, tachycardia, redness, angiœdema, hives, abdominal cramps …), a vasovagal reaction (normal breathing, bradycardia, pallor, sweat, cold and moist skin, nausea, vomiting …) injection “deciphers Dr. Therefore, Camille Braun (Civil vaccine allergy: true false | Hospices in Lyon).

Regarding non -immediate reactions, clinical manifestations are rarer, with skin symptoms, an altered general condition, joint pain, etc.

Inflammatory, sometimes impressive reactions

The majority of local reactions are pain, redness, edema. They result from non -specific inflammation, not an allergic reaction.

Arthus’ phenomenon is an inflammatory skin (redness. pain, necrosis) reaction, developing within 6 to 12 hours depending on the injection and most often regressing in two to three days. It is a hypersensitivity reaction mediated by IGG that can occur in subjects hyperimmunized by anterior injections of vaccine. “We can also sometimes observe a subcutaneous nodule, often associated with vaccines containing aluminum. Its appearance is delayed (a few days to weeks after injection). its often spontaneous resolution in one year, or even more. It probably does not reduce immunization ”, Indicates Dr. Camille Braun.

Rare contraindications

In addition to the microbial antigens themselves. certain components vaccine allergy: true false | of the vaccine may cause an allergic reaction: residual components of the culture medium, conservatives, adjuvants, stabilizing, surfactants, diluents …

However, almost all of these allergies do not constitute contraindications to vaccination.

Egg allergy concerns only certain vaccines cultivated there: yellow fever, flu, tick encephalitis. « The flu vaccine can be done in the majority of cases in the medical office. Medical surveillance is necessary in rare cases of severe anaphylaxis with egg. For yellow fever vaccines and tick encephalitis, patients must be sent to an allergist ”, specifies the specialist.

Gelatin allergy does not prevent vaccination either. “Many vaccines do not contain them (pneumococcus, flu, HPV, meningococcus, etc.) and, for others, an alternative without gelatin is often available (priorix for Ror, Varillarix for chickenpox, BCG-Medac for tuberculosis). Otherwise, we will address the allergist for a prior skin test ”, advocates Dr. Braun.

There is no vaccine allergy: true false | problem for antibiotic allergies: no cases related to the presence of antibiotic traces in vaccines has. been described.

It is also possible to vaccinate children under biotherapy, anticipating vaccination (before the first injection) for living vaccines. If necessary, you can vaccinate under hospital surveillance.

Communication from Dr Camille Braun (Lyon)