Anyone miss getting it when in close contact but then getting it another time?

[Twoforthree]

Ds was the only one in our family of four not to succumb to COVID last September. He’s now been in contact with another positive person. I’m just wondering whether he’s likely to get it now, given he escaped it last time.

Anyone been in this situation?

DS had it before Christmas (asymptomatic). His housemate was with him & I don't think they really socially distanced & didn't catch it. He then caught it about 3 weeks later. It was too long for it to have been from DS.