The Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) met on April 14, 2021 to discuss recent cases of cerebral venous sinus thrombosis (CVST) with thrombocytopenia that have occurred in 6 patients after receiving it the Janssen COVID-19 vaccine. Based on the information available, the panel was unable to decide on the next steps for Janssen’s COVID-19 vaccine, expanding the current recommendation for the break.
What is known
6 cases of CVST have been reported to the Vaccine Adverse Event Reporting System, all in women aged 18 to 48 years. Symptoms started 6 to 13 days after receiving the Janssen COVID-19 vaccine. In addition, 1 report of CVST was observed in a 25-year-old male patient during the Phase 3 clinical trial that supported the approval.
To date, 7,233,726 doses of the Janssen COVID-19 vaccine have been given, of which 1,495,400 doses have been given to women aged 18 to 50 years. The Janssen COVID-19 vaccine comprises less than 5% of the COVID-19 vaccines administered. There are currently around 13 million cans available.
No cases of CVST with thrombocytopenia have been reported when using Pfizer-BioNTech and Moderna mRNA COVID-19 vaccines. Thrombocytopenic thrombotic events have occurred after administration of the AstraZeneca COVID-19 vaccine. Both the Janssen vaccine and the AstraZeneca vaccine contain replication-incompetent adenoviral vectors that encode the spike glycoprotein of SARS-CoV-2.
What is not known
It is currently unknown what the true incidence of CVST with thrombocytopenia is or what specific risk factors exist for this potentially life-threatening condition with the Janssen COVID-19 vaccine. In addition, it is unclear whether other thrombotic cases with thrombocytopenia can occur after receiving the Janssen COVID-19 vaccine.
Recommendations for healthcare providers
Until a thorough assessment of the significance of these CVST cases can be made, the CDC continues to recommend a pause in using the Janssen COVID-19 vaccine. In patients who recently received the Janssen COVID-19 vaccine, the following symptoms may warrant further investigation as they may represent serious thrombotic events or thrombocytopenia:
- Strong headache
- Back pain
- New neurological symptoms
- Severe stomach ache
- shortness of breath
- Leg swelling
- Petechiae, or new or easy bruising
In patients with a thrombotic event and post-vaccination thrombocytopenia, laboratory testing for heparin-induced thrombocytopenia (HIT) using an enzyme-linked immunosorbent (PF4) test and consultation with a hematologist is recommended.
If the HIT test is positive or cannot be performed, treatment with heparin should be avoided. Rather, the use of non-heparin anticoagulants and high dose intravenous immunoglobulins should be considered.
See cdc.gov for more information.
- US Centers for Disease Control and Prevention. ACIP presentation slides: meeting on April 14, 2021. https://www.cdc.gov/vaccines/acip/meetings/slides-2021-04.html. Accessed April 15, 2021.
- US Centers for Disease Control and Prevention. Cases of cerebral venous sinus thrombosis with thrombocytopenia after receiving COVID-19 vaccine from Johnson & Johnson. https://emergency.cdc.gov/han/2021/han00442.asp. Accessed April 15, 2021.
This article originally appeared on MPR