Wednesday, December 23, 2020

Coronavirus 46 #LockdownNow

Which way to Birmingham?

I wouldn't start from here.

We saw in the spring that lockdown pushes R below 1. We saw from Wuhan that a thorough lockdown combined with effective isolation and support suppresses the virus to the point of elimination. China's covid death rate per million population is just 3. In the UK that figure in now over 1000 and rising. Excess deaths will have passed 100,000 before January is over, 12 months since the virus arrived and was allowed to spread.

Now would be the ideal moment for proper national lockdown. Many households are well stocked with food; for years we have got into the habit of shopping till we drop in the days before Christmas in the, normally false, supposition that shops won't open for ages. Schools and universities are closed for their holidays. A lot of people take a lengthy break from work and many industries all but shut down between Christmas and New Year. The next couple of weeks are the least disruptive time in the year for all but the most essential workers to stay at home.

This time we must do it right. The objective must be 'Zero-Covid', suppression and elimination. The 'protect the NHS' was the wrong philosophy. The NHS is to protect the people, not vice versa. Last summer Sir David King advised that education facilities should not reopen until prevalence was such that new cases were below 1 per day per million population. That's three orders of magnitude lower than the government's policy which has demonstrably failed. Online education with appropriate and effective support must be universal. Testing is, at last, happening on an appropriate scale, but testing on it's own is worthless without appropriate follow up action. While tracing is improving we are still not isolating effectively and there is not the adequate support that allows isolation to be effective.

We have to get the whole test, trace, isolate and support system working or the enormous effort and cost of a thorough lockdown will again be wasted.

We have to constantly remind ourselves that the virus spreads when people meet and if people do not meet then the pandemic will be over in just a few weeks. Waiting for the vaccines to save us is a disastrous approach. It won't provide herd immunity until at least next summer. While rolling out the vaccine as fast as possible, for now we must behave as if there is no vaccine.

Now is the moment. Now is our best opportunity to end the pandemic and prevent a second hundred thousand avoidable deaths during 2021. The government must give the leadership and the support to allow the people to stop the virus spreading.

#LockdownNow should be announced today.

Sunday, December 20, 2020

Coronavirus 45 Tragedy of Commons

Some sums in the head. Maybe one in a hundred people out there have covid. You'd have to be out and about, shopping, travelling or whatever, for quite a while before meeting a hundred people. But say you do meet someone who is infectious. If the reproduction number, R, is between 1 and 2, that infectious person will, on average, infect one or maybe two others, but they may, like you, have been out and about and met a hundred people, not just you. And you are sensible, you wear a mask, you keep your distance. You wonder what the chance of catching the virus will be if you go out and about. You know you have to multiply probabilities and though you don't have accurate numbers you know the probability of catching the thing if you go out is pretty low. One in thousands. A lower probability of harm than other things you do, skiing, horse-riding, smoking cannabis. Yes, on a personal level, going out is safe enough.

But you are thinking about yourself, not society. A one in a thousand chance sounds low but if one in a thousand people die from covid in a population of 67 million then 67,000 die. Tonight's government figure for UK death is 67,401. (The excess death number is about 80k and the second wave has a long way to go yet.)

There's another thing, if you do catch it, and with R>1, it doesn't stop there. You pass it on to others and they... until hundreds of thousands die. That's the inevitable outcome if R stays above 1. The arithmetic demands it.

And this is the new variant of the Tragedy of the Commons. Your behaviour may feel like a personal advantage, you get to go out and about, at least for a while, but when you, and everybody else who makes a similar judgement, behaves this way, disaster results. For everybody.

When deciding what to do we sensibly consider the personal short term risks and benefits. Big mistake. It is the commons that counts, the risks to society as a whole if everyone acts as you wish to.

Picture credit: Royal College of General Practitioners.