The United States announced, on Thursday (5), new restrictions on the use of the Janssen (Johnson & Johnson) vaccine against covid-19. Now, the immunizer should only be indicated for those individuals who cannot receive another formula. The decision is related to the rare cases of blood clot – one of its known adverse effects. The complication is called Thrombosis Syndrome with Thrombocytopenia (TTS).
In a statement, the Food and Drug Administration (FDA) detailed that only two profiles of people, over the age of 18, will be able to receive the Janssen vaccine against the SARS-CoV-2 coronavirus. Only the following groups are considered suitable for immunization:
- Individuals who cannot receive other vaccines against covid-19 for medical reasons, such as allergy to any component;
- People who have refused to receive a vaccine other than Janssen’s, for whatever reason.
Despite the decision, it is necessary to reinforce that covid-19, by itself, can cause thrombosis. So, the FDA usage review should not be seen as a way to discourage vaccination, but as a measure to increase the safety of the population when using available immunizers.
Why did the vaccine recommendation change in the US?
Basically, US health authorities have reviewed the data and incidence rate of adverse reactions from the Janssen vaccine. The bottom line is that for the majority of the population, the known and potential benefits of the formula do not outweigh the risks. At that point, the balance tipped the other way.
However, the risk is still considered rare and, therefore, the vaccine can be applied to some audiences. “We recognize that the Janssen Covid-19 vaccine still plays a role in the current response to the pandemic in the United States and throughout the global community. Our action reflects our updated risk analysis of STT [a formação dos coágulos] after administration of this vaccine and limits the use of the vaccine to certain individuals,” explained Peter Marks, director of the FDA’s Center for Biological Assessment and Research.
Risk of rare blood clots
It is worth explaining that the Thrombosis Syndrome with Thrombocytopenia is marked by the combination between the formation of blood clots and low levels of platelets in the blood. In some cases, it can be deadly. The condition can appear one to two weeks after the Janssen vaccine is given, according to the FDA.
In partnership with the Centers for Disease Control and Prevention (CDC), the FDA monitored all suspected cases of post-vaccination clot formation through March 18 of this year. In this interval, 60 officially confirmed cases were identified, nine of which led to the patient’s death.
The FDA has determined that “the reporting rate of STT is 3.23 per million doses of vaccine administered and the reporting rate of deaths from STT is 0.48 per million doses of vaccine administered.” In this way, the side effect can continue to be considered as rare, but, today, there are other options than vaccines that do not have this risk. It is in this context that they should be prioritized.
Janssen Adverse Effects Surveillance
“Today’s action demonstrates the robustness of our security surveillance systems and our commitment to ensuring that science and data guide our decisions. We have been closely monitoring the Janssen Covid-19 vaccine and the occurrence of STT after its administration, and we have used up-to-date information from our security surveillance systems to review the US,” Marks details.
It is important to note that the vaccine was registered for emergency use, due to the covid-19 pandemic, at the end of February 2021. In December of that same year, a CDC advisory committee advised that, during the vaccination campaign, professionals healthcare providers opted for mRNA (messenger RNA) formulas — such as the Pfizer/BioNTech and Moderna vaccines. Now, the new decision further limits the use of Janssen in North American territory.