by Aaron Xi ’22
Published May 2nd, 2021
On April 13, 2021, Johnson & Johnson paused all administration of their single-dose vaccine. This came after several reports “of a rare and severe type of blood clot” within six women between the ages of 18 to 48, causing the death of one and the critical hospitalization of another.
The six women afflicted with these rare symptoms suffered from thrombocytopenia syndrome (TTS), a low amount of blood platelets, and cerebral venous sinus thrombosis (CVST), a blood clot. What makes these cases different is the unusual combination of TTS and CVST that prevents the typical health treatment for blood clots from being used.
This “unique phenomenon” is under heavy research, and as of now, there is insufficient data to reach a definite answer. One hypothesis from Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, suggests that the rare clots are based on a specific adenovirus-based vaccine that differs from Pfizer and Moderna.
These cases are not entirely unprecedented. Although “blood clots and low platelets did not show up” in the phase three Janssen vaccine trials, a 25-year-old male patient “suffered CVST and had low platelets.” In addition, one of the six individuals who suffered from the rare clotting participated in a different clinical trial that occurred before the vaccine was authorized.
Out of the 6.8 million individuals that have already received the Janssen vaccine, these six cases do not seem like a significant amount. However, new reports of 11 other individuals suffering from TTS receiving the AstraZeneca vaccine had similar symptoms.
Although the cases are still limited, the implications of an unsafe vaccine may deter individuals from getting vaccinated. Officials believe that a longer pause could “fuel vaccine hesitancy and conspiracy theorists” and cause fewer Americans to get vaccinated. Since the exact cause is still unknown, the full implications of these cases are yet to be determined.
On April 23, after intensive investigation and a thorough safety review, the FDA and CDC concluded that the administration of the Janssen vaccine could be resumed, with caution to women younger than 50 years old. The FDA also recommended that warnings regarding the possibility of the rare blood clot be added to advertisements and other information panels.
According to Elliott Haut, a blood clot expert and trauma surgeon at Johns Hopkins School of Medicine, “the numbers so far are showing a rate of 1 case of clotting per 1 million people,” which means that overall, “the benefits of the vaccine still outweigh the risks.” Ultimately, however, “there have been no COVID-associated deaths among those who were vaccinated,” which means the vaccine itself is effective.
UPDATE (Apr. 26): Although the Johnson & Johnson vaccine is back in circulation, the setbacks could impact public opinion regarding the vaccine’s safety. The current number of reported vaccine recipients with the blood clot is 17.