Great news about the very positive effect the vaccines are having on Covid cases - onwards and upwards. Does anyone have any ideas why I have had 4 cold sores in 4 or 5 weeks? They started before my Covid vaccine so it isn't that. I had my last round of Rituximab in November 2020 after a my first doze a year earlier [the one in the middle was cancelled due to Covid]. I do get cold sores but the odd one perhaps every 6 months or less.