>>Assuming a asymptomatic set 4-6 times of verified infections hard hit countries with ~10% verified infections and 2/3 of population vaccinated should be close to the reachable level of immunity, with soon only breakthrough cases, allowing estimates on efficacy of natural and vaccine immunity over time and age group. Early antibody studies in NY and other places even estimated up to 10 times of undiagnosed / hidden Corona infections, so I don't think my guess is to far off. Unless NZ vaccinates at least those likely to have severe outcomes, your "dry wood" will pile up at later time.

NZ is all-in with Pfizer, which Israel says is 39% effective against Delta variant. This is confirmed by a very good pre-print Mayo study saying 42%

Impossible to achieve herd immunity or prevent infection crossing quarantine with those numbers, with herd immunity the justification for every mass vaccination effort in history, until now.

The other issue would be QALY (Quality-adjusted life years) which for decades has been a reproducible method of assessing healthcare cost-benefit. Basically QALY assesses quality as well as quantity of life saved or extended by an intervention towards a standardized figure including dollar cost. This allows funders and society to compare treatment modalities to decide on funding priority. Lower QALY cost is obviously preferable to higher QALY cost to achieve the same standardized QALY, helping to justify spending decisions that maximize benefit rather than responding to emotion or activist pressure.

In NZ, pre-C19 QALY cost was around $45,000 - meaning that's the cost paid for NZ healthcare to save or extend one year of standardized quality life.

Cost of NZ's C19 suppression/elimination strategy based purely on GDP loss (actually based on 25% of GDP loss to acknowledge alternative cost of mitigation versus elimination/lockdown) delivers a QALY cost of $8,500,000. Almost 200 times the pre-C19 cost.

This is roughly equivalent to dedicating NZ's entire annual healthcare spend to extend life for 800 people with heart disease- and that's just looking at GDP, not at QALY deficits from delayed screening or cancer treatment, depression/suicide etc etc.

I perceive a willful "turning away" from these sorts of calculations that have been standard epidemiological practice for decades, just as I do for "wear a mask" mandates without helping members of the public wear them properly so it's more than just a symbol.

I'd encourage other nations to ask politicians for the QALY calculations wrt national strategies- it's a basic method that will have appeared in courses and qualifying exams for every epidemiologist all over the world, so it's something that ought to directly underpin decision making- or at least used to be, until C19.

>>Tin-foil hats already wonder why
>>- antibody tests, which seem to be better now at recognizing early undiagnosed infections, are discouraged,
>>- vaccination status is kept out of infection / hospital admission / symptom severity / mortality statistics and
>>- "long covid" data is kept at anecdotal, not statistical level.

Current scuttlebutt is that Covid immunity involves T-cell as much as or more than antibody, which helps explain why mRNA vaccines that program antibody responses may lose effectiveness relatively quickly. There's no affordable/accessible T-cell test- yet- but the cost of antibody kits in Germany is now so low that you might as well self-test and hope for a positive IgG antibody result.

Vaccination status is now included for NHS data (though not split into Delta vs previous variants, unfortunately) but the upcoming Mayo paper breaks figures into months, with July 2021 almost 100% Delta, and also standardizes a 1000-person-day denominator so that counts aren't affected by large or small cohort size. My read of Mayo is that Delta is far less virulent than earlier strains but important to wait for final version since pre-print stuff can be problematic- e.g. recent leaked CDC document on Delta infectiousness that was full of error, but widely quoted ("Delta is as infectious as chicken pox" ... oops, no it isn't)