Excellent.

un-nerfed link: https://old.reddit.com/r/COVID19/comments/hdxwf5/intrafamili...

But does this get us a lot?

In Brooklyn and Queens between 0.2 and 0.25 percent of the total population (!) died.

So this sort of puts a floor on the IFR and 0.2 is not that far off from the IFR determined through serological testing – maybe a half or a third of that.

So yeah, maybe there is an effect – but can it really be a drastic effect? I don’t think there are orders of magnitude of difference in there, maybe a difference of a few percent (e.g. an IFR of 0.45 instead of 0.5 percent)?

My working hypothesis has been an IFR of around 0.5% for a pretty long time, which seems pretty realistic to me.

Well, this study estimates covid 19 by looking at survey data on influenza-like-illnesses. That means they were counting people who had flu-like symptoms.

Any potential people with covid19 but no symptoms would be above and beyond what’s being raised here.

I have seen Dr Raoult in France suggesting there was likely significant cross immunity from other coronaviruses. If it is the case, would the person develop covid19-specific antibodies after getting it?

IANAD, but you can have similar antibodies (which test positive) from previous infections with similar coronaviruses, not this one specifically.

So somebody who had no exposure to COVID-19 could test positive.

Afaik that's the main drawback of the antibody test.

What is the actual effect on the world if that’s true? I’m assuming that people who were infected but never developed symptoms or antibodies were still able to infect other people who might develop symptoms and antibodies.

How would you end up without antibodies? The virus just failed to replicate in your system and died out of its own accord? Or are we suggesting the people with no symptoms are still asymptomic carriers?

People without symptoms are also much less likely to spread. So likely your friend really didn’t get infected.

How would we know that if they don't even have an antibody response? You're resorting to anecdotal evidence but there is no way to confirm this hypothesis empirically on a large scale.

I guess it depends on what you mean by "significant amount", though.

Another anecdote from NY. I had mild symptoms in mid March that didn't exactly match what was being described in the press. Spending hours at the hospital trying to get tested seemed riskier, so I was never diagnosed. In late April I got tested at Mount Sinai hospital for antibodies as part of their study and I was positive, with a high titer. A friend of mine was, too, with a low titer. In a second test two weeks ago I still had the same titer, while she was negative. As an additional anecdote, without mention of other variables, the nurse taking the second sample told me that males had a higher titer on average. I think we also have higher mortality rates, though.