The US Food and Drug Administration (FDA) has limited the use of the Covid-19 vaccine developed by Janssen, a subsidiary of Johnson & Johnson (J&J), in adults aged 18 years and above, due to the risk of a rare blood clotting syndrome.
The US agency stated that the administration of the Covid-19 Vaccine is associated with the risk of thrombosis with thrombocytopenia syndrome (TTS), after evaluating recently reported TTS cases.
TTS is a syndrome characterised by rare and potentially life-threatening blood clots in combination with low levels of blood platelets.
The disease condition may rapidly worsen, regardless of timely diagnosis and treatment, and may lead to long-term and severe health consequences, with a high death rate.
According to the FDA, the known and potential benefits of the vaccine for the prevention of Covid-19 outweigh the known and potential risks in people aged 18 years and above.
FDA Centre for Biologics Evaluation and Research director Peter Marks said: “We recognize that the Janssen Covid-19 Vaccine still has a role in the current pandemic response in the United States and across the global community.
“Our action reflects our updated analysis of the risk of TTS following administration of this vaccine and limits the use of the vaccine to certain individuals.
“Today’s action demonstrates the robustness of our safety surveillance systems and our commitment to ensuring that science and data guide our decisions.”
Janssen’s single-shot Covid-19 vaccine was initially approved in the US, in February last year, to prevent Covid-19 in people aged 18 years and above.
In April, the FDA and the Centres for Disease Control and Prevention (CDC) recommended a pause in the administration of the vaccine due to six reported cases of TTS.
After the safety evaluation, the FDA and CDC have lifted the recommended pause regarding the use of the Janssen Covid-19 Vaccine.
Currently, the US FDA and CDC have been continuously monitoring for and investigating all the suspected cases of TTS reported to Vaccine Adverse Event Reporting System (VAERS).
In an updated analysis, the US agencies have identified 60 confirmed cases of TTS following the administration of the vaccine that were reported to VAERS through 18 March this year.
The authorised use of the Janssen Covid-19 vaccine is now revised, to include a warning statement that summarises information on the risk for TTS.
Marks added: “We’ve been closely monitoring the Janssen Covid-19 Vaccine and occurrence of TTS following its administration and have used updated information from our safety surveillance systems to revise the EUA.
“The agency will continue to monitor the safety of the Janssen Covid-19 Vaccine and all other vaccines, and as has been the case throughout the pandemic, will thoroughly evaluate new safety information.”
