I don't think vacines are the only solution to viral infections. They're all different, but there are many treatments for various viral infections after the infection has occurred. The reason for quarantines are to minimize the spread, the reason for the recommended duration of the quarantine is so that infected people can no longer transmit the virus. Some mechanism or another has 'cured' all the infected people that have not died from it. It's most likely their immune system which can be supplemented, if desired, by various medications that facts say are being fast tracked at this momment.
