R Number

[jennyjoan]

What would be the best number for R number (Covid) to be reached so that we are free again.

[New Judge]

Nil.

[jennyjoan]

I thought that Judge - to see that wonderful NIL - would be fabulous

[DTCwordfan]

Zero or - 2 - in that nothing comes in but we could go out and infect Europeans as revenge to them messing us around over Covid and Brexit.

[jno]

you already have, DTC, that's why the UK strain was developed.

[woofgang]

DTC how does 2 work and a desireable R number? That means every infected person infects two more.

[jno]

I took that as minus 2, woofgang?

[Sqad]

Free?
I suppose you mean back to pre Covid days.
It will never JUST be a number of the r value, but will depend on many factors, e.g modern antiviral treatments, success of the vaccination programme, state of the economy, all those factors will be taken into consideration rather than one target value of the "r" factor.

[Peter Pedant]

oh zero - - -
BUT anything under one is better than over one ( epidemic but the nearer one the less acute)

2 I took that as 2 and froggies dont matter - how rude!

The issue JJ is measured wobble - you can never be sure R = 1 say that is IS one. it could be 0.9 and it could be 1.1
Scientists have not been been able to get is under 0.3 - - 0.7 to 1.0 and the only problem is 0.7 is really OK and 1.0 is eek!

this was NOT foreseen when they plugged their models into the computers.

compare3 this to 15 m vaccinated which even if they are wrong by 10 000 either way, is still accurate to 1 in 1500 or 0.008 - or 0.8%

[jim360]

The natural R number (ie with no countermeasures etc) appears to be in the region of 3 to 3.5, depending on the strain. With lockdown measures, it appears that R < 1 is achievable. So the real question is what the effect of widespread vaccination is on R. If it doesn't bring the number down to one or smaller, then the disease would still be able to spread, and kill, in increasing numbers.

The answer is less than 1, anyway, or at least no more than 1. A disease that never quite goes away but also doesn't grow out of control again is presumably tolerable -- once you've reached low enough levels, that is.

[Peter Pedant]

what a party pooper - the lower the R number the freer we are is not a bad way of looking at it
and something to look forward to

the R number is used to estimate the proportion of those susceptible become infected in the time period you are looking at. The infected pool then go onto the recovered pool ( which is where the dead reside too) at a rate you can set or estimate
and you are now ready to run the S-I-R model on a computer.