J&J Vaccine Paused

April 16, 2021

On Tuesday, April 13, the FDA and CDC recommended a “pause” in the administration of the COVID vaccine by Janssen Biotech (a division of Johnson & Johnson’s (J&J)) due to reported cases of a rare type of blood clot potentially tied to the vaccine. States and providers rapidly heeded the advice. The CDC’s Advisory Committee for Immunization Practices (ACIP) held an Emergency Meeting to discuss the adverse events and the vaccine remains on pause. 

What it means.

The FDA and CDC are reviewing data involving six cases of a type of blood clot called cerebral venous sinus thrombosis (CVST) in women aged 18-48 who received the J&J vaccine 6-13 days prior. These patients also presented with low platelet levels – the cells responsible for clotting. It’s a rare situation where a patient would present with a blood clot, and low levels of cells that are critical to clotting. If doctors treat this situation like a normal clotting situation (with a drug called heparin that reduces clotting), it can exacerbate the problem, as the patients already have low platelet levels. 

FDA and CDC noted that educating providers about alternative treatment for individuals presenting with clots who have recently received the J&J vaccine is part of the reason for the pause.

If blood clots in relation to the COVID-19 vaccine sounds familiar, it’s because clotting incidents have been reported in relation to the Astra Zeneca COVID-19 vaccine given in the European Union. The New York Times explains the relationship here…

In two studies in the New England Journal of Medicine last week, research teams from Norway and Germany found platelet-attacking antibodies in the blood of some AstraZeneca vaccine recipients who had the strange clots…It’s not yet clear if there’s a similar link to the J&J vaccine. But the J&J and AstraZeneca vaccines, as well as a Russian COVID-19 vaccine and one from China, are made with the same technology…FDA’s Marks wouldn’t say if the weird clots may be common to these so-called adenovirus-vector vaccines. In addition to the AstraZeneca data, J&J makes an Ebola vaccine the same way and he said authorities would examine “the totality of the evidence”… The most widely used COVID-19 vaccines in the U.S. — from Pfizer and Moderna — are made with a completely different technology, and the FDA said there is no sign of a similar clot concern with those vaccines.

In setting recommendations for use of a vaccine, CDC relies heavily on the ACIP panel. ACIP is a group of medical and public health experts who develop recommendations on the use of vaccines in the United States. For instance, this Advisory Committee helps CDC set the childhood immunization schedule. In relation to COVID-19, the ACIP has voted on vaccination prioritization schemes as well as recommendations for the three products with Emergency Use Authorization – Pfizer, Moderna, and J&J. 

What it means if you’ve received the J&J vaccine. 

Dr. Fauci stated:

So, someone who had it a month or two ago would say, “What does this mean for me?” It really doesn’t mean anything. You’re okay, because if you look at the time frame when this occurs, it’s pretty tight from a few days, six to 13 days from the time of the vaccination. If someone was recently vaccinated, within days, I would tell them to, first of all, don’t get an anxiety because, remember, it’s less than one in a million. However, having said that, pay attention. Do you have symptoms? Headache? Do you have shortness of breath? Chest discomfort? Do you have anything that resembles a neurological syndrome? Obviously, if you have something as serious as a seizure, I mean, that’s pretty clear. Headache is the very common component of it because the sinus thrombosis that they have is the draining of the blood in the brain and it will cause enough symptomatology to make you notice it. Just tell people to just watch out for not feeling very well.

What is means… in general.

Dr. Fauci was quoted as saying this pause will likely be resolved in days to weeks, not weeks to months. However, no clear timetable has been set. While the J&J vaccine has not been as widely administrated as Pfizer or Modera products (attributable to the later Authorization from FDA and supply), it was widely viewed as critical for vaccinating hard to reach and vulnerable populations. With only one dose and no requirements for ultra-cold storage, it is easier for vaccination efforts reaching into in rural and underserved areas, homebound populations, and those who may be distrustful of the vaccine or medical system. The timing, recommendations for use, and impact on uptake of the product are all yet to be seen. 


FDA/CDC joint statement 

Jeff Zients, White House COVID-19 Response Coordinator statement 

Johnson & Johnson General Information

Reported Adverse Events

Viral Vector Vaccines

Different Vaccines

Vaccines for COVID-19

Frequently Asked Questions about Vaccination

Vaccine Safety and Monitoring (including v-safe).