Carl Hennigan

So let's go back to the swine flu pandemic.

It started in Mexico with a case fatality rate, as I remember, at about 10%.

Everybody panicked.

It dropped and dropped.

The lowest bound of the estimate by the end of the outbreak was 1%.

And then it dropped again to 0.01%.

And then eventually, I think it was Liam Donaldson at the time, did a report and said actually the fatality rate was 0.02% when he actually looked in the light of day.

It is very hard in the midst of a pandemic to understand what's going on.

But what makes this virus particularly sneaky and difficult to understand is two things.

There seems to be a lot of people with mild disease or asymptomatics.

And the reports say somewhere between 5% and 80%.

How's that for a precise estimate?

But that's what they're saying.

That's over 20 reports now say, here's a proportion of asymptomatic.

So they won't be tested.

They won't present with symptoms.

And so they won't be counted in the case fatality rate.

So we've discussed this before, trying to estimate what's called the infection fatality rate.

What's the rate of death in all those with the infection?

Now, it's interestingly, in Germany, they've just done this.