I listened to the lead of the study on the radio this morning - he certainly didn't suggest that there was "no immunity" and was careful about linking the fall

I listened to the lead of the study on the radio this morning - he certainly didn't suggest that there was "no immunity" and was careful about linking the fall in anti-bodies to immunity. I think it is clear that there is some connection though; not straightforward, but there is a link. On the other hand (as the scientist on the radio mentioned) apparently vaccines often work differently and it may be that they offer longer immunity.