[criticaltinker]

I have no primary sources to offer regarding this question.

But here's some pure speculation if you're interested - assuming immunological memory operates in a 'most recently used' fashion, then it would follow that individuals will develop an immune response that trends toward being most effective at neutralizing the viral profile that was last seen. Consequently, the studies and data that evaluate natural immunity vs vaccinated immunity could be fairly applicable. In practice I'm sure you'd see a blending of the two immune responses, but timing of exposure could play a big factor in weighting that balance.