Sorry another measles thread.
I live in the north west and have booked to bring my 5 year old to London for the day on Thursday just to go to the natural history museum and go home again. He’s fully vaccinated and has had the booster but his three year old sibling has only had the first dose (due to have his second next week!). Is it risky to visit? My 3 year old had heart surgery as a baby, he’s considered fully repaired now and doctors told us to treat him “normally” but I do worry a bit extra.
thanks