It's confirmation that the vaccines work the way we expect them to work. Also, this may help identify people that need a (or more) booster shots, or people that should be more careful even though they were vaccinated. Also it provides an explanation for people getting Covid after vaccination (breakthrough Covid as they call it here). Now you can say to people that scream: "Look they got vaccinated and still got Covid!" what likely happened and why that doesn't mean the vaccine is not doing what is should, in the population.

For example the people without (or lower concentrations of) antibodies may share certain traits/attributes (like recently undergoing chemotherapy I read in this thread somewhere), if we know that, we can avoid vaccinating these people too early (and thus needlessly) after treatment and we know we should protect them in another way.

It may all seem obvious, but I can tell you (as somewhat of a scientist myself), that any of these things could easily have been found to be not true and we'd have had to deal with that. Biology is complex, if we would have had to change models of how we think the vaccine works, that could have real world implication for how we deal with (partially) vaccinated populations for example.

I wonder if one's reaction to the vaccine is a measure for the magnitude of one's immune reaction and related to the effectiveness of the vaccine. I for one slept for 14 hrs after my first shot and spend another half day in bed feeling like I had the flu after the second. I'd like to thing I'm well protected now, but who knows. Only studies like this one can prove such hypotheses.

in short, water is wet studies, and water isn't dry studies are important, in case water is only wet under certain conditions.

So this is more of a “is ice wet” study?

Good points, but I have to say that at least the summary article smells of reductionist science to me. It's both "water is wet" and "water is the only way to put out a fire" at the same time.

Even if there is a "statistically significant" correlation between (lack of) this particular marker and breakthrough infection, it is still at least as possible that immunity requires a coordinated response from several parts of the immune system, with no part particularly dominant. A weaker response by one part could be compensated for by another part. If you're not good at neutralizing the virus but you're really good at preventing it from entering, you may be just as ok as someone with opposite strengths.

Another way to say that is that there very well might not be a relevant threshold of this one marker, or the threshold may be so extreme as to be uninteresting. We might need to combine additional markers.

(I really ought to read the actual study before nitpicking on its reporting, though.)

"Look they got vaccinated and still got Covid!"

And people still die with seatbelts. If these people were around 100 years ago we'd still be suffering from polio.

I guess they're expecting the vaccine to, you know, confer immunity? Like how nearly every vaccine except the mRNA ones do

Maybe they're expecting the vaccine to stop the transmission of the virus to others? Like how nearly every vaccine except the mRNA ones do

No vaccine has ever conferred absolute immunity to everyone.

The covid mRNA vaccines are extremely effective, far superior to the alternatives (the US is very fortunate to have never approved AstraZeneca), so I have no idea why you'd mention them in particular.

"The delta variant is now the dominant strain of SARS-CoV-2 in Israel, where researchers now estimate that the two-shot Pfizer vaccine is only 39% effective in preventing an infection within the country."

Source: https://www.salon.com/2021/07/28/pfizer-vaccine-less-effecti...

Um yeah, they're great.

It is not well known how many doses we need to get near full immunity. Some other vaccines require up to 3 doses https://www.cdc.gov/vaccines/schedules/hcp/imz/adult.html

Sounds like goal post shifting honestly. The mRNA clinical trials were done with 2 doses. It was sold as 90%+ effective on the 200 people they studied (erroneously claimed as over 40,000 people but I digress - that's information for only detailed oriented people to discover).

Now suddenly a 3rd is necessary? What happens when that fails, a second booster? A yearly vaccine like the flu shot (which barely works anyways)? Unfortunately for us humans, nature finds a way.

Speaking of nature, you know what confers full immunity? Having the infection and then recovering or having cross reactive immunity from a previous coronavirus strain.

Natural immunity is the undisputed champion of immunity.

Remember, these vaccines were developed for the original variant, goal post have not been shifted. Reality is. Nobody imagined that r0 would grow from 2.5 to 6.4 in such short time. Even infection does not give full immunity but so far it appears to be better than vaccines. Besides it comes with very heavy cost without vaccination. With vaccination it might be possible without heavy losses.

You mean like adenovirus vector vaccines do or inactivated virus Sinovac?

There is nothing to do with mRNA vaccines here.