How can you create a vaccine if you can be re-infected? Via CNBC:
A 25-year-old man in the U.S. state of Nevada has contracted the coronavirus on two separate occasions, a study in the Lancet Infectious Diseases journal showed, with the patient becoming seriously ill following the second infection.
It is the first confirmed case of a U.S. patient becoming re-infected with Covid-19, and the fifth known case reported worldwide.
The resident of Washoe County, who had no known immune disorders or history of significant underlying conditions, required hospital treatment on testing positive for Covid-19 for the second time.
He has now recovered, though the case raises further questions about the prospect of developing protective immunity against the coronavirus.