Emotions have been running high since the Food and Drug Administration recommended a pause in administering the Johnson & Johnson coronavirus vaccine in the United States. The sudden step was intended to give the FDA and the Centers for Disease Control and Prevention time to assess the threat of rare but serious blood clots in the brain that have developed in some vaccine recipients, with one fatality in the United States.
The pause on new J&J doses going into arms will remain in place for at least a week.
The CDC’s Advisory Committee on Immunization Practices, which has met weekly to review data about side effects from the various vaccines, convened Wednesday to discuss the data available on the clots — and determined that more is needed. While that information is being gathered, the pause on new J&J doses going into arms will remain in place for at least a week.
It’s important that Americans understand the essential basics of what’s going on and why it’s not time to panic.
In brief, the pause we’re seeing is something the FDA is accustomed to doing while trials are still ongoing — which in this case, they are. But the FDA’s emergency use authorizations for the vaccines, granted to fight a novel virus that’s sparked a global pandemic, mean that every move from the government is receiving intense scrutiny. That heightened attention has both put U.S. health agencies in the spotlight, highlighting their every decision, and prompted a wave of snap judgements about each choice — whether they’re helpful or not.
That was clear when Tuesday’s federal action was met with many equally intense reactions. Atop the list: worries about the psychological impact on consumer confidence in the Covid-19 vaccines and whether the U.S. was unintentionally promoting vaccine hesitancy at a time when we are racing against more infectious variants.
Meanwhile, other countries including Australia made pre-emptive statements that they will not use the J&J-made vaccine. By the end of the day on Tuesday, the entire United States had stopped vaccination programs with J&J, pivoting to reschedule appointments and allay the concerns of women who received the vaccine in the last several weeks.
If you’re still unclear on why the pause was necessary, here’s the short version: The FDA and CDC are working together to investigate six cases of cerebral venous sinus thrombosis — aka serious blood clots near the brain — in combination with low platelets, called thrombocytopenia. (Platelets are a part of your blood that help to form clots and stop or prevent bleeding).
What we do know is that the United States system of surveillance and safety monitoring is active and rigorous — and that system has worked.
All six cases occurred in women aged 18 to 48 and between six and 13 days after they received the J&J vaccine. Details are still sparse, but the FDA made clear that the cases in question were also associated with an atypical reaction to the normal drugs used to dissolve blood clots, which actually counterintuitively worsened the problem. One of the six cases was fatal; another individual remains in critical condition. (And while the U.S. cases so far have been seen in women, a similar vaccine technology used in the European Union suggests rare clots are possible in men as well.)
A pause like this one is generally brief — days, at most — and largely directed at the clinicians giving the doses. It bids them to be wary of certain symptoms presenting in people who recently had the vaccine or to ask if someone with severe headaches, shortness of breath, severe abdominal pain, unusual swelling or neurological symptoms had recently been vaccinated. There is still much we don’t know. Based on the available information, these clots may develop via a similar mechanism as that seen with AstraZeneca’s vaccine — an immune response that occurs very, very rarely that produce these blood clots. When the next week ends, we’ll see where the CDC lands on giving J&J the green light again. What we do know is that the United States system of surveillance and safety monitoring is active and rigorous — and that system has worked. Around 7 million doses of the J&J vaccine have been administered so far in the United States, with a robust vaccine adverse event reporting system in place that feeds information to the CDC and FDA with any and all vaccine-related symptoms. Growing evidence caused the CDC to flag concerns around the clinical developments of serious blood clots, culminating in the pause of the vaccine administration in the United States. But understanding how to communicate these safety signals is up to many of us who are administering and advocating for vaccines around the world. I, for one, see no reason to slow down or hesitate in that advocacy. Over 100 million people in the U.S. have been vaccinated with at least one dose with few of these safety signals detected. Could more occur? Certainly — but a Covid-19 infection poses more risks to all age groups, including the very clots of concern, at even higher rates than seen with vaccination. The novel coronavirus has taken so much from us: lives, jobs, physical and mental well-being. With the arrival of miraculous vaccines thanks to science and incredible dedication to facts, we’re close to closing the door on this dark time in our history. We can’t give the virus space to take away the thing we’ve held on to for this last year: hope.
Dr. Kavita Patel
Dr. Kavita Patel is a teaching professor of medicine, Division of Hospital Medicine, at Stanford University and a board-certified internal medicine physician. She served in the Obama administration as director of policy for the Office of Intergovernmental Affairs and Public Engagement in the White House. Her area of expertise is around the intersection of health policy, clinical medicine and innovation. She also spends time advising venture capital and is a medical contributor for NBC News. 
