Relapsing Cases News Today

That, and the race for a vaccine tonight. >> reporter: tonight, an encouraging turn in the battle against the pandemic. after fears that virus patients in south korea had gotten it a second time, the south korean cdc thinks its likely that people cannot be infected twice. but that conclusion is still preliminary. and they dont know how long that immunity lasts. those scientists pointing to those relapsing cases, now saying they were actually due to testing failures. >> these results are very enc...