News Flash

Health Alerts

Posted on: April 14, 2021

Clinician Alert: Pause on Johnson & Johnson (J&J) COVID-19 Vaccine Use

Clinician Alert: Pause on Johnson & Johnson (J&J) COVID-19 Vaccine Use

Requested Actions

  • Hold off on administering any J&J vaccine pending the outcome of a safety review by the Centers for Disease Control & Prevention (CDC) and the Food & Drug Administration with respect to extremely rare reports of cerebral venous sinus thrombosis (CVST).
  • Follow guidance in the CDC’s Health Alert for triaging patients who have received J&J vaccine and whose presentation is concerning for CVST.
  • Be aware of the recommendation to avoid heparin in the treatment of vaccine-associated CVST.
  • Please notify the Health District at 425-339-3503 and submit a report to CDC’s Vaccine Adverse Event Reporting System (VAERS) if you have seen or later see such a case or another thrombotic phenomenon temporally associated with COVID-19 vaccination.
  • Continue storing your J&J vaccine. Store unpunctured multi-dose vials of the Janssen COVID-19 Vaccine at 36°F to 46°F (2°C to 8°C) and protect from light. Do not store frozen.


  • Through CDC’s COVID-19 vaccine safety surveillance system (e.g., VAERS, VSafe), CDC has noted reports of 6 episodes of CVST among the 6.8 million recipients of this vaccine to-date in the United States. These extremely rare reports are still being reviewed and definitive attribution to the vaccine remains under investigation.
  • The background rate of CVST is estimated to be 2-16 per million annually.
  • Typical risk factors for CVST include female gender, prothrombotic conditions, oral contraceptives, pregnancy and the puerperium, malignancy, infection and trauma.
  • Typical clinical presentations include headache, encephalopathy, focal neurologic deficits, and/or seizures. Intracerebral hemorrhage and increased intracranial pressure are the primary pathophysiologic events.
  • Diagnosis is by brain MRI and MR venography.
  • All six cases noted by CDC occurred in women aged 18-48 years at an interval of 6-13 days following administration of J&J’s adenovirus vector vaccine. Two had concurrent intra-abdominal thromboses and all had varying degrees of thrombocytopenia (nadir range: 10K-127K/uL).
  • These cases are reminiscent of other rare thrombotic events observed in Europe associated with Astra-Zeneca’s adenovirus vector vaccine. These, too, have occurred in the context of thrombocytopenia and may be associated with platelet-activating antibodies against platelet factor-4, making the use of heparin potentially harmful unless heparin-induced thrombocytopenia (HIT) testing is negative. Non-heparin anticoagulants and high-dose intravenous immune globulin should be considered in treatment of patients who present with immune-mediated thrombotic events with thrombocytopenia after J&J COVID-19 vaccination. Involving a hematologist in such a patient’s care is strongly recommended.
  • During this pause, CDC and FDA recommend deferring use of the vaccine until they complete their safety review. CDC’s Advisory Committee on Immunization Practices will begin addressing this today, April 14, and we are hoping for resolution or at least further interim guidance on the matter by the end of the week.
  • Approximately 150,000 doses of J&J vaccine have been administered in Washington State and 24,000 in Snohomish County. Approximately 60% of the Snohomish County J&J allocation has been administered through our mass vaccination clinics; most of the rest has gone out through retail pharmacies. We are not aware of any CVST occuring among local vaccine recipients. Few if any local health care system vaccine providers would be expected to have J&J vaccine in their inventory at this time.

Facebook Twitter Email

Other News in Health Alerts

Health Alert: Ebola Disease Outbreak

Posted on: October 13, 2022

Health Advisory: Acute Flaccid Myelitis

Posted on: October 11, 2022

Update for Clinicians: November 4, 2020

Posted on: November 4, 2020

Influenza Circulating in Snohomish County

Posted on: December 10, 2019