The Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) are recommending a temporary pause of the use of the Janssen COVID-19 vaccine following 6 reported cases in the United States of a rare and severe type of blood clot.

According to a joint statement, the CDC and FDA are currently reviewing data involving these 6 cases in which cerebral venous sinus thrombosis (CVST) occurred in combination with thrombocytopenia among women 18 to 48 years of age. In all 6 cases, symptoms developed 6 to 13 days after vaccination. In a media briefing, the FDA reported that 1 of these cases was fatal, while another patient is in critical condition. It was also noted that the administration of heparin may be dangerous in this setting and that alternative treatments should be given.

As of April 12, more than 6.8 million doses of the Janssen COVID-19 vaccine were administered in the US, indicating that these adverse events appear to be extremely rare. A temporary pause in the use of the vaccine is being recommended out of an abundance of caution, according to the Agencies. In a statement, vaccine manufacturer Johnson & Johnson added that a decision was also made to delay the rollout of the vaccine in Europe.

Continue Reading

The CDC’s Advisory Committee on Immunization Practices (ACIP) will be holding a meeting on April 14, 2021 to review the cases and assess their potential significance. The FDA will also continue to review and investigate these cases. 

If a patient presents with symptoms suggestive of CVST, healthcare providers should inquire about COVID-19 vaccination status. Individuals who have received the Janssen COVID-19 vaccine should contact their healthcare provider if they develop severe headache, abdominal pain, leg pain, or shortness of breath.

Adverse events related to COVID-19 vaccines should be reported to the Vaccine Adverse Event Reporting System (VAERS)


1.    Joint CDC and FDA Statement on Johnson & Johnson COVID-19 Vaccine. [press release]. Silver Spring, MD: US Food and Drug Administration; April 13, 2021. 

2.    Johnson & Johnson statement on COVID-19 vaccine. [press release]. April 13, 2021.

This article originally appeared on MPR