Over one year ago, the news became saturated with information on COVID-19, a novel coronavirus pandemic that has since swept the globe. At the time of this article, there are 137 million COVID-19 cases worldwide, with an associated 2.95 million deaths. In the United States alone, the numbers are staggering: 31.3 million cases and 562,000 deaths. As the vaccine roll-out has begun, many people are beginning to feel slightly more optimistic about the future. However, regulatory agencies are showing some concern about the single-shot Johnson & Johnson vaccine following reports of dangerous blood clots.

According to Fierce Pharma, both the European Medicines Agency (EMA) and the United States’ Food & Drug Administration (FDA) are investigating the vaccine’s potential to cause rare but serious blood clots. This news follows reports of multiple cases of unusual blood clots with associated thrombocytopenia (low platelet counts).

COVID-19 Vaccines

Altogether, there has been a great deal of debate over the safety of burgeoning COVID-19 vaccines. In fact, outside of Johnson & Johnson, AstraZeneca has also been under fire for blood clot issues. As reported in The Guardian:

Since rare but severe clotting was seen in some people following vaccination with AstraZeneca’s Covid-19 vaccine, researchers worldwide have been grappling to understand why the clotting syndrome, known as “thrombosis with thrombocytopenia” (clotting with a low platelet count), occurs.

Most cases of these clots occurred in veins in the brain (a condition called cerebral venous sinus thrombosis, or CVST), though some occurred in other veins, including those to the abdomen (splanchnic vein thrombosis).

Unfortunately, this provides some merit to the Johnson & Johnson claims, as both AstraZeneca and J&J use viral vector technology for their vaccines. Interested in whether you should use a viral-vector vaccine or a mRNA vaccine? Click here.

So far, 3-4 cases of thrombosis with thrombocytopenia have been reporting in Europe following J&J vaccination. Of these, at least one was fatal. While the FDA is aware of this, the organization also stated that there is no causal relationship between the vaccine and the blood clots, a sentiment similarly echoed by Johnson & Johnson. However, additional investigation and evaluation are still being performed. As this occurs, regulators will determine whether or not specific safety-related warnings are necessary.

So far, over six million Johnson & Johnson vaccine doses have been administered in the United States over the past two months.