I know I can have my booster as I had Covid 2 months ago, had NHS invite email for the booster. I'm just wondering whether there's any data about the optimum or most strategic time to get the booster, to get maximum benefit of immunity for longest. I've put it off for a few weeks, as I'm still feeling a little bit ill with a cough and weird Covid-head feeling. But this is genuinely just curiosity not anxiety, I'm definitely planning to get the booster next week or so.