The May 5 notice said the change was made due to the risk of developing thrombosis with thrombocytopenia syndrome, which causes blood clots in combination with low levels of blood platelets, with symptom onset approximately one to two weeks following administration of the Johnson & Johnson vaccine.
“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,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research. “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.”
