What you should know about the Johnson & Johnson/Janssen COVID-19 vaccine pause

April 13, 2021  //  FOUND IN: News

Earlier today, the Centers for Disease Control and Prevention and the Food and Drug Administration recommended that providers pause on giving out the Johnson & Johnson/Janssen COVID-19 vaccine.

It comes after six women who received the vaccine experienced blood clots within two weeks after vaccination — and after more than 6.8 million people in the U.S. received the one-dose COVID-19 vaccine. The decision was made out of an abundance of caution and is a sign that the well-being of patients remains at the core of the vaccination process, which includes monitoring for any adverse side effects not previously reported from clinical trials.

Michigan Medicine has not administered any J&J vaccine through our patient vaccine program. Some individuals received the J&J vaccine during their participation in a Michigan Medicine research trial. If you received the J&J vaccine as part of a research trial, contact your study administrator with questions.

If you have other questions about the reported blood clotting concerns that led to a pause in administering the Janssen COVID-19 vaccine, you’re not alone.

Geoffrey Barnes, M.D., M.Sc., a cardiologist and vascular medicine specialist at the Frankel Cardiovascular Center, weighs in.

What is your take on the concerns about blood clotting after the Johnson & Johnson/Janssen vaccine?

Barnes: It’s important to note that we do not yet know if there is a real risk of clotting associated with the J&J/Janssen vaccine. So far, there are very few reported cases (six) despite millions (6.8m) of doses administered. However, given the events in Europe and Canada that appear to be associated with the AstraZeneca vaccine (which is not currently available in the U.S.), I think it’s wise to pause to investigate these cases.

Male doctor in dark suit stands in lobby of Frankel Cardiovascular Center.
Geoffrey Barnes, M.D., M.Sc.

There has been a specific mechanism proposed for the rare clotting events after the AstraZeneca vaccine, and we don’t yet know if the same mechanism might be involved with these clotting events found after the Janssen vaccine.

What should people who have already gotten the Johnson & Johnson/Janssen vaccine know?

Barnes: Keep an eye on how you’re feeling. Clinicians and patients should watch for any signs or symptoms that can signify a clot within 1-3 weeks after the AstraZeneca or J&J/Janssen vaccine. Those may include severe headache, vision changes, severe abdominal pain, or nausea and vomiting.

Notably, if patients develop muscle aches, chills, or nausea and vomiting within 1-2 days after the vaccine, that is likely a known side effect of the vaccine and not related to a clot. But if these develop 4-5 days after the vaccine, patients should be evaluated for a possible rare blood clot.

If a patient does develop signs or symptoms of a clot within three weeks after an AstraZeneca or J&J/Janssen vaccine, evaluation with routine coagulation tests and imaging is recommended. If thrombocytopenia (low platelets) are found, work up for vaccine-induced thrombotic thrombocytopenia (VITT; similar to heparin-induced thrombocytopenia) and avoiding heparin anticoagulation is recommended until further testing can be completed.

What should you do if you already have an appointment for this vaccine?

Barnes: Check with the place you’re registered with to see if they’re pivoting to other vaccine manufacturers or if you’ll have to make a later appointment.

But you can also develop blood clots if you get COVID-19, right? Should we be worried about both?

Barnes: Patients who develop COVID-19 and get hospitalized are at risk for developing blood clots as well. The risk of blood clots in patients with COVID-19 is far higher than the very small risk of a blood clot following a COVID-19 vaccine. Overall, the benefits of COVID-19 vaccination greatly outweigh the very small risks.

What other common medications do we take that give us a risk of blood clots?

Barnes: Many women use estrogen-containing oral contraceptive pills. These pills are associated with a risk of blood clots, including the rare clots that have been seen with the AstraZeneca vaccine.

What is the final message you’d like readers to know?

Barnes: COVID-19 is a serious public health crisis. Vaccines are a critical element to getting the pandemic under control.

The blood clots identified after the AstraZeneca and Janssen/Johnson & Johnson vaccine are concerning, but seem to be quite rare. Physicians are aware of this condition and have the necessary tools to diagnose and treat patients if this very rare condition occurs.

Furthermore, there has not been a sign of blood clot risk following the Pfizer or Moderna COVID-19 vaccines. Therefore, I strongly urge everyone to get vaccinated as soon as possible.        

Click here for more FAQs about the COVID-19 vaccines.