The eighth pharmacovigilance report of the Spanish Agency for Medicines and Health Products (AEMPS) offers more information on the adverse reactions reported up to September 10. The Janssen vaccine has registered in this last work new adverse reactions under suspicion and evaluation.
Identified Side Effects
1. Immune thrombocytopenia: The PRAC recommended that the Janssen vaccine SmPC and package insert be updated to include information on autoimmune thrombocytopenia as a possible adverse reaction. Immune thrombocytopenia is a medical condition in which the immune system mistakenly attacks blood cells called platelets, which are necessary for normal blood clotting, and destroys them.
2. Thrombosis Syndrome with Thrombocytopenia: in Spain, up to August 8, 2021, 5 confirmed or probable cases of this syndrome have been registered in people vaccinated with Janssen. Two of the patients died.
3. Guillain-Barré Syndrome (GBS): This syndrome is a very rare immune system disorder that causes inflammation of the peripheral nerves and can result in pain and/or numbness, initially in the extremities, muscle weakness and difficulty in wandering GBS has been included in the product information for the COVID-19 Vaccine Janssen vaccine as a possible adverse reaction.
Possible adverse reactions identified
The evaluation of the following adverse events has already been completed, which are added as possible adverse reactions to this vaccine in the technical data sheet and package insert:
1. Lymphadenopathy (inflammation of the lymph nodes): it is estimated that its appearance frequency is less than 1 case per 1,000 vaccinated people.
2. Paresthesias (unusual sensation in the skin, such as tingling or chills) and hypoesthesias (numbness or decreased sensitivity, mainly in the skin). The frequency of occurrence of paresthesias is estimated at less than 1 per 100 vaccinated persons and that of hypoesthesias at less than 1 case per 1,000 vaccinated persons.
3. Tinnitus (persistent ringing in the ear), which appears in less than 1 person per 10,000 vaccinated. Additional data and analyzes have been requested from the MAH in order to better characterize the nature of these cases, especially the clinical course and duration of symptoms.
4. Diarrhea and vomiting. The frequency of diarrhea has been estimated as uncommon (occurring in less than 1 in 100 vaccinated persons) and that of vomiting as rare (occurring in less than 1 in 1,000 vaccinated persons).
5. Dizziness. It is added as a possible adverse reaction after vaccination.