I find a lot of remain voters persist in phrasing things as "Brexit is the cause of" X, Y or Z, which simply leads to the response "You are ignoring Covid and Ukraine".   It would help, perhaps, if the remain voters could adopt something more along the lines of "Almost every country suffered from covid and from the effects of the Ukraine war. What can be pointed to that show the UK has managed better than other places because of Brexit freedoms?"

And, by the way, 'early vaccines' is not one. What matters on vaccinations is the total number of lives saved, not the date of the earliest injection nor the number delivered. Effectiveness is what counts, not process.