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Comment by MiguelVieira | Hacker News Reader

I've been using 0.5% for mental math, rounding down from the lower bound from this study in The Lancet:

https://www.thelancet.com/journals/laninf/article/PIIS1473-3...

I would be surprised if, after this current wave of infections, the percentage of people with antibodies in the US is higher than the low single digits.

Herd immunity without a vaccine is a pipe dream. Our best bet is to massively ramp up testing and contact tracing and really start pushing the number of infections down to a point where parts of society can start functioning again.

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Herd immunity isn't a pipe dream it is just one hell of a sacrifice. And we'd better check the immunity actually lasts before we try that. Frankly I've never been a great fan of the 'flatten the curve' explanation, sure the graphs seem nice but I reckon the peak in those graphs is drawn too low by several orders of magnitude.

In the Netherlands a fatality rate of 0.5% would mean it'd take about a year for herd immunity to kick in assuming we managed sustain the peak that occurred about 2 weeks ago (and it's somewhat dubious whether the healthcare system actually can sustain that peak).

Let me quantify that sacrifice in a US-centric way with some napkin math to ballpark:

328.2 million (Approximate population of the US [1]) * 80% for herd immunity (based on an R0 5.7 [2]) * 1% = 2.6 million people die.

If the fatality rate is 0.5% instead, then 1.3 million people die If the fatality rate is 0.1%, we're still looking at ~260k-ish people.

That's pretty grim.

This situation is still developing so hopefully those numbers get adjusted downwards as later information becomes available.

For reference, ~1.2 million people died to heart attacks and cancer in 2017. [3]

[1] https://www.census.gov/popclock/ [2] https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article [3] https://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm

One aspect that people seem to be ignoring with the whole 'healthcare capacity' argument is the mental health of the healthcare workers. The capacity everyone talks about is IMO the acute capacity, not really the chronic sustained capacity.

That's because just like in a war, it isn't realistic to expect the frontline soldiers to stay in combat for longer than weeks at a time before they start to exhibit PTSD and their effectiveness begins to drop.

Unless we have large reserves of doctors and nurses to rotate in and out I think we should be very careful not to take them for granted.

It's not a pipe dream. It's just that it needs to happen in a different way. We need to massively increase number of isolation rooms, icu beds etc. (just like China did building that hospital in 10 days), massively increase number of clinicians (take every one in their last year of nursing school and med school and get them in the hospital, not making decisions but carrying out basic tasks; use a draft if you have to, just like Italy did), and massively increase testing capacity (~4x from today's capacity in US), and massively increase ventilators, add ubiquitous temperature checking (to enter any building other than your house, you need to confirm temp) and then just open up the economy and let it rip. With enough testing and enough surge healthcare capacity, we can do this.

So a 0.5% fatality rate sounds like "only" five times the rate of the flu. EXCEPT that I would bet that if you thoroughly traced all the asymptomatic but positive for the flu, it's fatality rate would decline also and it still causes significant deaths.

Total Covid deaths are already at a "mild flu season" level already after a month and continuing some level of exponential growth after social distancing.

It's sad and awful but it seems like with the current administration approach, the response of ramped up contract tracing has pretty much flown away and with these figures, we're looking 500K deaths, 250K over the next two month and another 250K over a longer period. Hide your parents...

Except that a huge portion of those deaths are in places that may have already reached herd immunity, if the ratio of comfirmed / actual cases is as small as this study suggests.

NYC, for example, has 123k confirmed cases. Multiply by 50, and you have 6.1M, which is close to 70% of the total population.

Where are you getting the assumption that only 1 in 50 infected are confirmed? That seems like an especially low confirmed case to infection ratio.

Directly from the article. It’s the lower-bound estimate for confirmed to infected found by the study.

You should read it before commenting.

I’m not a virologist or epidemiologist, so I might be off-base here, but: the flu’s really well understood isn’t it? Medicine’s been studying it basically forever. I’d be really surprised if our fatality rate for it wasn’t pretty accurate and didn’t already have asymptomatic cases factored in.

> Herd immunity without a vaccine is a pipe dream. Our best bet is to massively ramp up testing and contact tracing and really start pushing the number of infections down to a point where parts of society can start functioning again.

The problem is, a vaccine is also a pipe dream. So we're going to have to all get infected over some sort of timeline that doesn't cause societal collapse. Also known as flattening the curve.

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