Image of Karen L. Furie, M.D., MPH

The blood clot-related condition that’s been reported following some Johnson & Johnson’s COVID-19 vaccinations also is a risk of COVID-19 infection, according to a special report by the American Heart Association/American Stroke Association Stroke Council Leadership.

The organizations on Friday jointly released the report, which covers signs and symptoms of the condition and preferred treatment options. Although “extremely rare” in both cases, the likelihood of blood clots is eight to 10 times higher following a COVID-19 infection than it is after receiving the J&J vaccine, the organizations stated.

Federal health authorities recently lifted a pause on the J&J vaccine after studying a handful of reports of a serious stroke/blood clot condition called cerebral venous sinus thrombosis, or CVST, occurring alongside thrombocytopenia (low blood platelet count). The two together are called thrombosis-thrombocytopenia syndrome, or TTS. Further, when TTS is linked to receiving a COVID-19 vaccine, it is called vaccine-induced immune thrombotic thrombocytopenia, or VITT. 

“COVID-19 infection is a significant risk factor for CVST,” said Karen L. Furie, M.D., MPH, lead author of the special report, chair of the department of neurology at the Warren Alpert Medical School of Brown University, and chief of neurology at Rhode Island Hospital. But the public can be reassured by investigations from the Centers for Disease Control and Prevention and the Food and Drug Administration that the risk of developing the condition is minuscule, she added.

“The likelihood of developing CVST after a COVID-19 vaccine is extremely low. We urge all adults to receive any of the approved COVID-19 vaccines,” she said.

That said, anyone complaining of CVST symptoms should be asked whether they recently have been vaccinated, she added. TTS/VITT symptoms typically have occurred several days to 2 1/2 weeks after being vaccinated with the J&J vaccine. In the United States, the most common reported symptoms have been:

  • severe headaches; 
  • vomiting; 
  • back pain; 
  • fatigue; 
  • weakness or the inability to move one side of the body (hemiparesis); 
  • inability to speak or understand speech (aphasia); 
  • loss of consciousness; and 
  • abdominal pain.

The key to treatment in all patients with suspected CVST due to a COVID-19 vaccine is non-heparin anticoagulants such as argatroban, bivalirudin, danaparoid, fondaparinux or a direct oral anticoagulant, the report stated. “No heparin products in any dose should be given,” the authors emphasized.

“With the right treatment, most patients can have a full recovery after CVST, TTS or VITT,” Furie said.

The CDC and FDA investigated 15 reported cases of TTS in the United States among the almost seven million adults who received the J&J vaccine before the temporary pause on April 13. These all occurred in women aged 18 to 59 years, the authors reported.

Full treatment guidelines can be found here.