The problem is that I know 2 people who tested positive in March and again in December. Apparently Ferrán Torres too.2 million of the most vulnerable is good news and will surely soon start to have an impact on deaths and illness. I can hear an ambulance siren as I type this. Such horrid times for people. Sadly in some ways the combination of how contagious this latest strain is and the vaccine roll out getting faster will help us get to a higher degree of immunity quicker. Not far off a million people catching it in the last week I would imagine. Circa half a million officially and I would imagine same again not actually tested. 20 percent of Manchester of London have already had it already.
Which suggests Immunity is transient.