I don't buy the 'no immunity' thing. If there's no immunity then we're looking at the death of society. Bye everyone!
It could be it confers some immunity...but we don't really know how much...or how long...and some people won't build enough immunity to protect them, especially those who are at greater risk in the first place....
Sorry you don't buy it....hope we don't learn the hard way what we refuse to accept.