The Food and Drug Administration added a warning to the fact sheet for the Johnson & Johnson COVID-19 vaccine saying that the shot may lead to an increased risk of a nerve condition called Guillain–Barré syndrome. The agency says that the benefits of the vaccine still outweigh the risk.
There have been around 100 cases of the syndrome reported among the roughly 12.6 million people who have received the Johnson & Johnson vaccine, the Centers for Disease Control and Prevention said in a statement to The Washington Post. It’s a very rare complication, but people who have received the shot appear to be around 3 to 5 times more likely to develop Guillain–Barré syndrome than the general population.
There’s no sign that the Moderna or Pfizer / BioNTech vaccines carry a similar risk.
In Guillain-Barré syndrome, the body’s immune system attacks the nerves. It can cause tingling in the hands and feet, weakness, and coordination problems. Most people recover fully, but it can lead to permanent nerve damage in some cases.
The syndrome has been linked to vaccines before. The US stopped using a swine flu vaccine in 1976 after reports that people who took the vaccine developed Guillain-Barré. Some years, there is a small increased risk of the syndrome with the seasonal flu vaccine — usually around one or two additional cases for each 1 million flu shots administered. The CDC notes that people may be more likely to develop Guillain-Barré from the flu than from the flu shot.
This is the second health risk associated with the Johnson & Johnson vaccine. US health agencies recommended pausing the administration of the shot in April after it was linked to a rare clotting disorder. The company added a warning about the risk of the disorder, and the pause lifted after 10 days.
Agencies have not recommended a pause on the vaccine this time. The vaccine remains available and will simply feature an additional warning label. People in the United States also have access to the Moderna and Pfizer / BioNTech vaccines.
Experts were hopeful that the Johnson & Johnson shot would play a major role in the US vaccination campaign because it only takes one dose, instead of the two doses needed for either Moderna or Pfizer / BioNTech. So far it has been administered to less than 10 percent of people vaccinated in the US.
The number of people who get vaccinated each day in the US has fallen to around 500,000, down from a peak of around 3 million in April. The number of COVID-19 cases has started to climb again as the Delta variant takes hold around the country.