First phrasing makes more sense than the second one to me -- what would it even mean for somebody to be "90% immune" to a disease?
It's the same as 'herd immunity', where each member is '90% immune' and as a result the herd is 'more immune' than if only 10% of its members were 100% immune.
Hasn't this virus already mutated to a bunch of different strands? Could it mean you're immune to 90% of the known variations of the virus?
What are you basing that on, when there are known cases of people getting coronavirus and then still contracting the other strain of it?
A patient must present a infection and the particular virus must be sequenced, and then present with an infection later on where the virus is again sequenced and identified as sufficiently different from the first sample. Otherwise it cannot be deemed a re-infection.
If these small differences in the genomic sequence are already a different strand, I don't know, not an expert. But all 5 (?) cases known so far had a different sequence identified the second time.
> The genomes of the patient’s virus samples from April and June displayed significant genetic differences between them, suggesting that the patient was infected twice by 2 distinct COVID-19 infections.
I’d read of known second infections that are from different strains, but scientists also question lasting immunity from COVID-19 infection because other coronaviruses are seasonal.
It was possible to positively identify a reinfection because the two infections were due to different strains. That was just the means of positively and objectively identify a reinfection. However, nothing was asserted regarding if the patient was immune to the first strain the first time around. In fact, it seems that the hallmark of reinfections is that they are far more critical than first infections. This also means that the first infections is far milder than the second one. Well, the thing about the immune system is that it is able to fight mild infections without developing immunity if they are too mild to trigger a full response from the immune system.
OK. The longevity of the immunity is also an issue perhaps; at least they have written articles about people becoming re-infected; so even the people who do become immune may not stay that way forever...
In my country there have been hundreds of thousands of confirmed Covid infections. There have been <100 confirmed re-infections.
It's very early to draw the conclusion that people in general don't build up lasting immunity, and there is more than enough data to support that most people do build up immunity of several months at least. If the latter wasn't true you'd see much more re-infections.
OK, some (needed) good news..
Because the reports from Denmarks Mink fiasco indicated that antibodies were not as effective on the mutation that appeared there short time ago. This would contradict the one-fits-all immunity argument.
I don't think that argument is being made at all.
In fact, you only need to consider that the max efficiency that's advertised is 90% to acknowledge that this vaccine is not a silver bullet.
For the "danish mink mutation" - even if the exception to the rule - some of the above statements might not be true.
I admit I know very little on how immunity to diseases work, but I imagine that with viruses there is a chance it'll progress to a full blown infection even if you are vaccinated in some cases.
I'm just saying how you can have a single person that's 90% immune to something vs. Having 90% of people immune against one strain of a virus.