A physician who treats clotting disorders explains what to look out for.
Yesterday, the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) recommended pausing vaccination with the Johnson & Johnson vaccine against COVID-19. The government agencies are investigating reports of severe blood clots in six women who received the vaccine. Although rare – six cases among 6.8 million people vaccinated – researchers want to understand the risks better.
What does this news mean for patients who received the Johnson and Johnson vaccine, and those still waiting to get their first dose of any COVID vaccine? Blood disorders expert and physician researcher Steven McKenzie, MD, PhD, sheds light on common questions.
Why is there concern over the J&J vaccine?
Although six cases among 6.8 million J&J vaccine recipients may not seem like cause for great alarm, the regulatory agencies decided to pause the J&J vaccination out of an abundance of caution and to give researchers time to investigate. We know this is a rare event, but we’ve seen similar types of rare clotting disorders in response to other medicines. They want to make sure they’re checking for the cause as well as any identifiable risk factors. We should know more soon.
Does this mean there’s a similar risk for the Pfizer and Moderna vaccines as well?
No. We have not seen a single case of this type of clotting in 122 million people who have received the Pfizer or Moderna mRNA-based vaccines.
Getting the COVID-19 vaccine is still extremely important to stopping the spread of the disease and reducing the risk of hospitalization or death.
What should the people who already received the Johnson & Johnson vaccine do?
We don’t have a lot of information yet. Based on the six patients who had an adverse reaction, we know their reactions happened between six and 13 days after getting the vaccine. These types of reactions don’t always appear right away, but if you got the vaccine more than one month ago, you’re very unlikely to have a reaction. If you just received the vaccine within the last month, you may want to look out for symptoms.
What symptoms should we look out for within 1-3 weeks of getting the J&J vaccine?
Symptoms of this type of blood clot can include severe headache, shortness of breath, abdominal pain, or pain in the backs of your legs. If you have these symptoms it’s important to get in touch with a doctor quickly. However, feeling flu-like symptoms (chills, fever, fatigue) in the first 48 hours after vaccination are considered normal side-effects from the vaccine.
Are men at lower risk since all of the cases so far are in women?
We don’t have enough information to say. The AstraZeneca vaccine in Europe was associated with cases of abnormal clotting in both men and women, so we can’t rule out the risk for men just yet.
Is there treatment if I develop clots from the J&J vaccine?
Absolutely. Because we understand some of the biology behind this reaction, we have some guidance on how to treat this specific kind of blood clot. We treat many clotting problems with a drug called heparin. But because in rare cases heparin causes a similar immune reaction to what we’re seeing to the J&J vaccine, so we recommended to avoid it. However, there are many other non-heparin blood thinners we can use first, as well as steroids and IV immunoglobulin that can help. The key is early recognition.
If you have any symptoms or questions, please contact your physician or advance practice provider right away.