Patients should be informed of a rare but serious clotting risk following vaccination with Johnson & Johnson’s single-dose COVID-19 jab, especially women under the age of 50, federal health authorities warn. Patient and provider awareness, coupled with availability of other vaccines, can help along with vaccine decision-making and catch and treat potential clotting cases early, according to the latest report from the Centers for Disease Control and Prevention (CDC).

The CDC and FDA last week lifted a nationally recommended pause on J&J's vaccine rollout after an advisory committee determined the benefits of vaccination, such as preventing COVID-19-related hospitalizations, outweigh the risks of rare but serious clotting. The product’s FDA emergency use authorization (EUA) has been amended to reflect the warning of remote risks of serious blood clots. Regulators were investigating 15 reports of so-called thrombosis with thrombocytopenia syndrome (TTS) amid a backdrop of nearly 8 million vaccine recipients.


The CDC is now investigating two new clotting cases that occurred alongside low platelets, bringing the total number of instances to 17. A CDC spokesperson told Fox News that one case of thrombosis with thrombocytopenia syndrome (TTS) under investigation occurred in a male vaccine recipient, and the other in a female, both under age 60.

Thus, all but one reported clotting cases have occurred among women aged 18-59. The greatest risks were reported among women aged 30 to 39 at a reporting rate of 11.8 TTS cases per million doses administered.

"Updated patient education and communication materials reflecting this warning are critical to ensure that women aged <50 years are aware of the increased risk for TTS and that other COVID-19 vaccines are available (i.e., mRNA vaccines)," the latest CDC report reads. "The EUA fact sheet should be provided to all vaccine recipients and their caregivers (as relevant) for careful review before vaccination with any authorized COVID-19 vaccine."


Treatment for TTS cases differs from the usual treatment for blood clots, and federal health authorities have advised providers against using heparin, which could be dangerous in this case.

The CDC said it would continue to monitor any additional cases of TTS and update the risk-benefit assessment as needed. 

Fox News’ Alexandria Hein contributed to this report.