Lingering symptoms from COVID-19 are “unprecedented” compared to other viral infections. And though the number of people experiencing "long COVID" is unknown, experts estimate that millions of Americans could be affected.

Could an out-of-order immune system be to blame for lingering symptoms?

PRODUCTION CREDITS:

Produced by: Emily Zendt Production Assistance: Christina Monnen Animation: Edgeworx Additional Footage: NAID, CDC/C.S. Goldsmith and T.G. Ksiazek

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