About 100 people of the 12.8 million Americans who have received the Johnson & Johnson vaccine have developed a rare side effect, Guillain-Barré syndrome, in which the immune system attacks the nerves, producing weakness and tingling in the extremities, the Washington Post reports.

While the occurrence of the complication is rare, the Food and Drug Administration has issued a warning to be included with information about the vaccine.  The agency, however, continues to recommend people get vaccinated, saying the benefits far outstrip the risks.

The Centers for Disease Control and Prevention, which compiled the data on the development of the complication, noted that 95 people who developed Guillain-Barré syndrome required hospitalization.  One person reportedly died, although the circumstances of the death were not revealed. 

Guillain-Barré syndrome is not typically a fatal disease, and most people fully recover from it with little or no lingering effects.  The cases related to the Johnson & Johnson vaccination are overwhelmingly found in white men over the age of 50.

The Guillain-Barré syndrome side effect has not been detected with the Pfizer or Moderna vaccines.  More than 320 million doses of those two vaccines have been administered in the United States.

Typically, 3,000 to 5,000 cases of Guillain-Barré syndrome arise in the United States arise annually.  While the syndrome is not completely understood, researchers believe it is caused by a viral or bacterial infection.