Very few things are a policy. A thread.

Herd Immunity is not a policy, it is a phenomenon in nature whereby transmission is suppressed via vaccination or the consequences of natural infection. /1 https://twitter.com/mlipsitch/status/1321624408205774848

Zero COVID is not a policy. It's where we'd all like to be, but seems unlikely to be achievable for most countries with notable exceptions in Asia and Oceania. /2

Waiting for a vaccine is not a policy. For new strains of influenza, we'd be unlucky not to have a good vaccine within 6 months or so, but for everything else there is no way to quantify a reasonable timeframe or probability of success. /3

Protecting the vulnerable is not a policy, it's a moral obligation by which civilisations should be judged. /4

Lockdown is not a policy, it's a way of buying time that is often needed, but one that has massive health and economic costs. /5

Keeping the healthcare system within capacity is not a policy, although the consequences of insufficient beds are judged to be particularly societally corrosive. /6

I could go on - but the point is that a policy worthy of the name won't just focus on any one of these, but should rather be a holistic approach to harm minimisation during a terrible event. /end