Pausing Use of the Johnson & Johnson/Janssen COVID-19 Vaccine

Updates as of April 23, 2021:

Effective April 23, 2021, CDC and FDA recommend that use of the Johnson & Johnson/Janssen COVID-19 Vaccine resume in the United States. However, women younger than 50 years old should be made aware of a rare risk of blood clots with low platelets following vaccination and the availability of other COVID-19 vaccines where this risk has not been observed. Read the CDC/FDA statement.

In their joint statement, the two agencies stated the following:

  • Use of the Johnson & Johnson/Janssen COVID-19 Vaccine should be resumed in the United States.
  • The FDA and CDC have confidence that this vaccine is safe and effective in preventing COVID-19.
  • The FDA has determined that the available data show that the vaccine’s known and potential benefits outweigh its known and potential risks in individuals 18 years of age and older.
  • At this time, the available data suggest that the chance of TTS occurring is very low, but the FDA and CDC will remain vigilant in continuing to investigate this risk.
  • Physicians and other clinicians administering the vaccine and vaccine recipients or caregivers should review the Janssen COVID-19 Vaccine Fact Sheet for Healthcare Providers Administering Vaccine (Vaccination Providers) and Fact Sheet for Recipients and Caregivers, which have been revised to include information about the risk of this syndrome, which has occurred in a very small number of people who have received the Johnson & Johnson/Janssen COVID-19 Vaccine.

CDC will publish an update in Morbidity and Mortality Weekly Report early next week related to the Advisory Committee on Immunization Practices (ACIP) recommendation and is updating relevant clinical materials and guidance. An update to the Johnson & Johnson/Janssen EUA has been published by the FDA.

Original article, published April 16, 2021:

CDC and FDA have recommended a pause in the use of the Johnson & Johnson/Janssen COVID-19 vaccine in the United States out of an abundance of caution, effective Tuesday, April 13. Of the 6.8 million Johnson & Johnson COVID-19 vaccine doses administered in the United States to date, six cases of a type of blood clot called “cerebral venous sinus thrombosis” (CVST) were seen in combination with low levels of blood platelets (thrombocytopenia). Montgomery County health officials announced on April 13 that they would comply with this guidance, as did the Maryland Department of Health. On April 14, the Maryland Department of Health directed all clinicians to pause administration of Johnson & Johnson COVID vaccines until further federal guidance is issued.

CDC is asking all physicians to:

  1. Pause the use of the J&J COVID-19 vaccine until the ACIP is able to further review these CVST cases in the context of thrombocytopenia and assess their potential significance.
  2. Maintain a high index of suspicion for symptoms that might represent serious thrombotic events or thrombocytopenia in patients who have recently received the J&J COVID-19 vaccine, including severe headache, backache, new neurologic symptoms, severe abdominal pain, shortness of breath, leg swelling, petechiae (tiny red spots on the skin), or new or easy bruising. Obtain platelet counts and screen for evidence of immune thrombotic thrombocytopenia.
  3. In patients with a thrombotic event and thrombocytopenia after the J&J COVID-19 vaccine, evaluate initially with a screening PF4 enzyme-linked immunosorbent (ELISA) assay as would be performed for autoimmune HIT. Consultation with a hematologist is strongly recommended.
  4. Do not treat patients with thrombotic events and thrombocytopenia following receipt of J&J COVID-19 vaccine with heparin, unless HIT testing is negative.
  5. If HIT testing is positive or unable to be performed in patient with thrombotic events and thrombocytopenia following receipt of J&J COVID-19 vaccine, non-heparin anticoagulants and high-dose intravenous immune globulin should be strongly considered.
  6. Report adverse events to VAERS, including serious and life-threatening adverse events and deaths in patients following receipt of COVID-19 vaccines as required under the Emergency Use Authorizations for COVID-19 vaccines.

CDC is asking physicians with a stock of this vaccine to:

  1. Mark any Johnson & Johnson/Janssen vaccine in your inventory “Do not use. Awaiting guidance.”
  2. Continue to store the vaccine in the refrigerator between 2°C and 8°C (36°F and 46°F).
  3. Follow vaccine storage practices and continue to monitor and document storage unit temperatures.

Standing Orders for an Adverse Event Remain the Same

While the Johnson & Johnson/Janssen vaccine is under Emergency Use Authorization, physicians and other health care professionals are required to report the following adverse events to the Vaccine Adverse Event Reporting System (VAERS):

  • Vaccine administration errors (whether associated with an adverse event [AE] or not)
  • Serious AEs (irrespective of attribution to vaccination)
  • Multisystem inflammatory syndrome (MIS) in adults or children
  • Cases of COVID-19 that result in hospitalization or death
  • Any additional AEs and revised safety requirements per the Food and Drug Administration’s conditions for use of an authorized vaccine throughout the duration of the EUA

Physicians and healthcare professionals are encouraged to report to VAERS any clinically important adverse events that occur after vaccination, even if they are not sure whether the vaccine caused the adverse event. More information is available in the standing orders for the Johnson & Johnson/Janssen vaccine. An overview of how to report to VAERS is available at

About the Initial FDA/CDC Recommendation to Pause Administering the Vaccine

The CDC’s Health Alert Network (HAN) sent out an alert on April 13 on Cases of Cerebral Venous Sinus Thrombosis with Thrombocytopenia after Receipt of the Johnson & Johnson COVID-19 Vaccine. The alert describes six patients (after 6.85 million vaccine doses administered) described in VAERS reports that came to attention in the latter half of March and early April of 2021 and developed symptoms a median of 9 days (range = 6–13 days) after receiving the J&J COVID-19 vaccine.  All six cases occurred among women aged 18–48 years. The interval from vaccine receipt to symptom onset ranged from 6–13 days. One patient died.

These reports following the J&J COVID-19 vaccine are similar to reports of thrombotic events with thrombocytopenia after receipt of the AstraZeneca COVID-19 vaccine in Europe: “Both vaccines contain replication-incompetent adenoviral vectors (human [Ad26.COV2.S] for J&J and chimpanzee [ChAdOx1] for AstraZeneca) that encode the spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19.”

For greater detail on these cases and more in-depth guidance from the CDC, refer to HAN-00442. The AMA also posted a discussion on the new guidance with the FDA’s Director of the Center for Biologics Evaluation and Research on April 13.

Referral to the CDC’s Advisory Committee on Immunization Practices (ACIP)

CDC convened a meeting of the Advisory Committee on Immunization Practices (ACIP) on Wednesday, April 14, to further review these cases and assess their potential significance. At the close of their session, ACIP stated that it “wanted more data before deciding whether to resume use of Johnson & Johnson’s single-shot coronavirus vaccine, calling for more information on the risks, cause and frequency of a rare and severe type of blood clot identified so far among six of the 7.5 million people who received the shot.” The committee will “reconvene within a week and a half, acknowledging the urgency of making a decision about a vaccine that is a key part of the strategy to end the pandemic in the United States and globally.” (4/14, Washington Post, Sun, Johnson)

The follow-up meeting to discuss Johnson & Johnson/Janssen  COVID-19 vaccine will be held virtually on April 23, 2021, 11:00 AM to 5:00 PM.

In an interview with the Washington Post, Helen Keipp Talbot, M.D., M.P.H., an associate professor of medicine at Vanderbilt University and committee member of ACIP remarked, “We are very fortunate because we have multiple other alternatives in the U.S. to help stop this pandemic. We have very good, well-proven alternatives where we are not seeing safety signals. I think that puts us in a little bit of a different position, and we can be much more cautious and thoughtful and use the old model of, ‘First, do no harm.’”

CNBC (4/14, Lovelace, Mendez) reported that Sandra Adamson Fryhofer, M.D., of the American Medical Association was in favor of a pause: “There is enough supply of the Moderna and Pfizer vaccines to continue rapid vaccinations across the U.S… I know there are many patients that have not been able to get vaccinated that need to get vaccinated, but we want to make sure these vaccines are safe.”

Further Reading

The American Society of Hematology (ASH) will soon be releasing a resource on vaccine-induced prothrombotic immune thrombocytopenia. Please visit