After I wrote this, about governments' lockdown exit strategies, I posted a copy on Facebook. I received a number negtive comments.

Some were about the issue of immunity: people saying that we don't currently know if our bodies have any ability to acquire immunity from infection by Covid-19. This BBC article gives a good summary of the current situation, based on expert opinions. The key take-away is the statement that "The question is not whether you become immune, it's how long for". Basically, given that there are no effective treatments for Covid-19, if your body doesn't mount an immune response to the coronavirus, you will die of the disease. The only thing that we don't yet know is how long the resulting immunity lasts, although the fact that antibody tests are now available to show whether you have had the disease shows that immunity lasts for at lest a few weeks or months, at least for many people.

There were also comments to the effect that my opinions about the exit strategy were wrong, and based on no evidence. I found this odd, because the UK government, and others, have talked about herd immunity quite a bit. In the absence of a vaccine, herd immunity can only come from being infected (and recovering, obviously). Governments are hoping that the populace develops herd immunity, and the only way to get that is for enough people to be infected, and for them to develop immunity. My opinions on the exit strategy are therefore based on published official statements and policy.

Governments around the world are gradually relaxing their lockdowns, and carefully monitoring infection rates as they do so, to maximise infection rates within the limits of their health-care systems' ability to cope, all to build up herd immunity.