By Amanda Sangster - April 15, 2021
A little over a month after granting emergency use authorization for the single-dose Johnson & Johnson vaccine, the U.S. Food and Drug Administration and Centers for Disease and Control have called for a nationwide pause on administering the shot after reports surfaced of six people developing a rare kind of blood clot.
While more than 6.8 million doses of the Johnson & Johnson vaccine have been administered in the U.S., Moffitt Cancer Center has not administered any of them.
The six cases where blood clots occurred were among women age 18-48 with symptoms showing six to 13 days after vaccination. In these cases, cerebral venous sinus thrombosis (CVST) was seen in combination with low levels of blood platelets. This kind of blood clot forms in the venous sinuses and can block the blood in the brain from draining to the heart.
A joint statement released by the FDA and CDC April 13 said that the call for a pause was out of an abundance of caution to, “Ensure that the health care provider community is aware of the potential for these adverse events and can plan for proper recognition and management due to the unique treatment required with this type of blood clot.”
I received the Johnson & Johnson vaccine – Should I be worried?
If you received the Johnson & Johnson vaccine over a month ago and have not experienced any symptoms, experts say you shouldn’t be worried.
“The blood clotting appears to affect only one out of every one million people,” said Dr. John Greene, chair of Moffitt's Infectious Diseases Department. “This is an extremely small percentage and the risk for developing CVST is very low. Also, symptoms would reveal themselves sooner.”
If you have received the Johnson & Johnson vaccine in the last three weeks, you should keep an eye out for the following symptoms:
- Severe headaches
- Blurred vision
- Abdominal pain
- Trouble speaking
- Numbness in legs, arms or both
- Shortness of breath
If you experience any of the above symptoms, you should seek out medical care immediately. Letting your health care provider know that you’ve recently received the Johnson & Johnson vaccine will guide them on how to treat these symptoms, which may be different from what’s normally used to treat blood clots.
Can we expect the same side effects from other vaccines?
Experts say it’s very unlikely to see similar effects with the Pfizer and Moderna vaccines because they are made differently. Also, there have been over 180 million doses of Pfizer and Moderna administered.
“The Johnson & Johnson vaccine is an adenovirus, like the annual flu shot, while the Pfizer and Moderna vaccines use messenger RNA,” said Greene. “After vaccinating so many millions of people, we would have seen these symptoms already.”
Should I not get vaccinated?
Despite the pause on administering the Johnson & Johnson vaccine, experts still agree that getting vaccinated against COVID-19 is a good idea. The vaccines have been proven to prevent people from dying from COVID-19 and from infection of the new variants emerging.