Disclaimer: I'm Irish, working in tech but my hobby that gets me more of a social life is involvement with an Irish political party. The new variant accounted for 10-25% of these new cases over the period of that spike. The spike happened two weeks after Christmas when lock-down restrictions were lifted, as planned in October, so people could have a respite after 9 months of all this. Did the government misjudge just…
Actually the new strain is already responsible for 45% of infections in Ireland (as per yesterday's NPHET briefing) while it was 10% at the beginning of the year IIRC So yeah it's not the whole story, but it is an important part of it.
If the new variant caused a big increase in R then I doubt the lockdown would have brought R under 1 in the U.K., which it clearly has, surprisingly from just about after Christmas.
I started out healthily sceptical that the new variant was significantly more infectious, and now I’m extremely suspicious.