[native_samples]

The UK now has a similar test positivity rate to what it had in November 2020 yet a hugely vaccinated population.

If the vaccinated aren't spreading it then you're suggesting that the unvaccinated have become drastically more infectious for no apparent reason and in ways that don't show up in contract tracing data. I think the alternative explanations are more likely to be correct: the vaccine is actually not a vaccine in the traditional sense, it's more like a prophylactic. Vaccinated people aren't getting an immune response in the normal areas where it would usually enter and exit, like the nose and lungs, instead it's being injected into the arm.

Also, COVID tests don't actually detect COVID or even SARS-CoV-2, they detect RNA debris from destroyed SARS-CoV-2. Thus it's expected that if someone's body fights off the virus immediately if they're exposed to it, they will still test positive.

[samus]

The unvaccinated population is not uniformly distributed though. The vaccines is not rated for the age younger than 12 yet, and it will still take a while to roll it out in the younger age groups. Also, I wouldn't be surprised if most vaccine refusers are part of groups who collectively refuse to vaccinate. We know from measles outbreaks that this is often the case. Finally, most vaccines achieve their maximum effect only if both doses are given. If only one is given, all bets are off.

> Also, COVID tests don't actually detect COVID or even SARS-CoV-2, they detect RNA debris from destroyed SARS-CoV-2. Thus it's expected that if someone's body fights off the virus immediately if they're exposed to it, they will still test positive.

Slightly untrue. The particles gathered from infected and spreading persons are fully functional, by definition. To distinguish these cares from immune people, one would have to determine the percentage of viable virus particles. Hard to tell whether that's even feasible at scale. It's not too bad though. At worst this causes a higher than expected false-positive rate.

[native_samples]

It's not rated for children because they appear to be immune to COVID and thus basically no safety results can possibly make the risk/reward tradeoff make sense in that age group.

"one would have to determine the percentage of viable virus particles. Hard to tell whether that's even feasible at scale ... It's not too bad though. At worst this causes a higher than expected false-positive rate."

I'm not sure you're aware of the scale of the problem. There have been studies that correlated PCR test results with ability to do viral culturing and concluded about 60% of all positive test results did not imply infectiousness. For example, this one:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8166461/

[samus]

> There have been studies that correlated PCR test results with ability to do viral culturing and concluded about 60% of all positive test results did not imply infectiousness.

My point was that the viral culturing might not be feasible for large-scale testing. In that case, we might have to stick to PCR.

[native_samples]

Yes, governments use PCR because it's fast and mechanical.

The correct response to the PCR not detecting what people actually need to know is to shut down mass testing entirely. There is no point in mass testing if it creates chaos and doesn't help, which is what's happening (there is no correlation between testing levels and incidence levels, killing the theory that test test test = better results).

[danhor]

> you're suggesting that the unvaccinated have become drastically more infectious for no apparent reason

Isn't that the point of concern about the variants? Alpha is vastly more infectious than the original and delta is even more infectious than Alpha, which is the reason why they're able to become the dominant strain in unvaccinated populations (england in early 2021 & india with delta). Both have some immune escape but less than e.g. the gamma variant which hasn't become dominant in most countries with high vaccination rates.

(now, since the covid vaccines don't mean complete sterile immunity, just like all others, increased infectiousness also leads to problems)

The PCR tests do detect the virus if the body fought of the virus immediately, but can also measure the amount remaining (the cycle count) which has a cutoff point. Thus it often doesn't get counted as "infectious".

The antigen tests (the fast, cheap ones) don't trigger on small amounts, also leading to issues and that results in them being more-or-less useless to detect infected vaccinated people.

[native_samples]

It's not clear they're actually more infectious. Claims that they are come from invalid methodologies like comparing the growth rate of one variant when it's new against the decline rate of another when it's old, or making assumptions like the one you just made above. Generally, it's good to treat any claim made by the field of epidemiology as suspect. They aren't incentivised to use statistics correctly.

Re: PCR:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8166461/

In light of our findings that more than half of individuals with positive PCR test results are unlikely to have been infectious, RT-PCR test positivity should not be taken as an accurate measure of infectious SARS-CoV-2 incidence. Our results confirm the findings of others that the routine use of “positive” RT-PCR test results as the gold standard for assessing and controlling infectiousness fails to reflect the fact “that 50-75% of the time an individual is PCR positive, they are likely to be post-infectious”