Dr. Jason Zucker, an infectious disease specialist at NewYork-Presbyterian/Columbia University Irving Medical Center and instructor in medicine at Columbia University Vagelos College of Physicians and Surgeons, shares what you should know about the J&J vaccine, its safety, and what to watch for if you’ve already gotten the J&J shot.
The pause in April was a recommendation by the CDC and FDA “out of an abundance of caution.”
After initial reports that six women between the ages of 18 and 48 developed a rare blood clot within one to three weeks of vaccination, health authorities learned of nine additional cases in women and one in a man. Authorities reviewed the data and resumed the rollout of the J&J shot 10 days later, but with a warning added to its label about the risk for a rare blood-clotting disorder. “A review of all available data at this time shows that the J&J/Janssen COVID-19 Vaccine’s known and potential benefits outweigh its known and potential risks,” the CDC said in a statement.
“Pauses are common and allow health authorities to assess the situation and communicate with healthcare providers on recognizing symptoms and treating patients appropriately,” says Dr. Zucker. “A pause doesn’t mean that there isn’t an important role for this vaccine.”
If you’ve already gotten the J&J vaccine, don’t panic.
“The risk of these severe adverse events from the J&J vaccine remains extremely low. The risk of getting COVID-19 in the United States is higher,” says Dr. Zucker.
The CDC recommends contacting your healthcare provider and seeking medical treatment if you develop any of the following symptoms:
- severe headache
- new neurologic symptoms
- severe abdominal pain
- shortness of breath
- leg swelling
- tiny red spots on the skin (petechiae)
- new or easy bruising
The J&J vaccine uses a different technology from the first two vaccines approved in the U.S.
Unlike the Pfizer and Moderna vaccines, which are mRNA vaccines, J&J’s is a viral vector vaccine. This means that the vaccine is delivered via an adenovirus, a type of virus that normally causes colds.
The adenovirus is engineered to include a snippet of SARS-CoV-2-DNA, which encodes the spike protein – the part of the coronavirus that latches onto cells. This snippet is then sent to your cells to produce mRNA, which tells your cells to make copies of the spike protein. Like the mRNA vaccines, this prompts an immune response.
“Your immune system recognizes the spike protein as abnormal and develops antibodies against it,” says Dr. Zucker. According to the CDC, people are considered fully vaccinated two weeks after getting the single-shot J&J vaccine.