US regulatory agency limited the application of the immunizer against covid in the face of rare cases of thrombosis
Anvisa (National Health Surveillance Agency) announced on Friday (06.May.2022) that it will maintain the indication of Janssen’s single-dose vaccine against covid-19. On Thursday (May 5th), the FDA (Food and Drug AdministrationUS regulatory agency) decided to limit the use of the immunizer because of the rare risk of causing blood clots.
The Brazilian agency evaluated that the benefits of the vaccine compensate: “To date, the benefits outweigh the risks for all vaccines approved by Anvisa”. And he concluded that “At this time, the agency does not identify the need for regulatory action regarding the Janssen vaccine or any other”.
Cases of thrombosis syndrome with thrombocytopenia (when there is the formation of blood clots) associated with adenovirus vaccines are very rare and usually occur on exposure to the 1st dose. Contraindications for use are already included in the package insert, including not applying a booster dose to those who had the disease.
In the note (read the full text below), Anvisa said it had a meeting with the FDA to assess the situation. At the meeting, the US agency stated that the vaccine is safe, but prefers to prioritize others “in the face of very rare risk”.
In the US, the Janssen injection can be given in cases where other approved vaccines are not available, when the use of other brands is contraindicated, or if the recipient does not accept another immunizer.
According to Anvisa, the Ministry of Health must define “prioritizing one immunizer over another”.
Here is the full text of Anvisa’s statement:
“On April 22, after the FDA communicated in the forum of regulatory agencies (ICMRA) that it would restrict the use of the Jansssen vaccine, Anvisa met with this agency to evaluate the data and understand the rationale of the decision. During the meeting, it was informed that there is no new safety concern, but given the very rare risk of TTS, the FDA understands that the use of other vaccines in that country should be prioritized.
“Adenovirus vaccines have a risk of thrombosis syndrome with thrombocytopenia, already described in a package insert approved by Anvisa. These are very rare cases, which usually occur after exposure to the first dose of vaccine from this platform.
“In Brazil, the Janssen and AstraZeneca/Fiocruz adenovirus platform vaccines are approved. Thus, even if the individual has previously taken the Covid-19 vaccine from another platform, exposure for the first time to an adenovirus vaccine in a booster dose can generate, in a very rare frequency, the unwanted effect of TSS.
“Anvisa maintains the continuous evaluation of the benefit-risk balance of all vaccines authorized in Brazil. So far, the benefits outweigh the risks for all vaccines approved by Anvisa. Thus, at this time, the Agency does not identify the need for regulatory actions regarding the Janssen vaccine or any other.
“As for the restriction of use, the contraindications already approved are included in the package insert, including the one of not administering a booster dose to those who presented TTS in the first dose.
“It is noteworthy that the Ministry of Health is responsible for defining the immunization policy and the evaluation of health technologies, in order to define the prioritization of one immunizer over another, which are reflected in the Vaccination Operational Plan against Covid. -19.”