That Africa study says "CCR5delta32 is most common in Africa, and Africa has the highest rate of covid mortality, so CCR5delta32 may be increasing covid mortality."

Obviously not as good as comparing the frequency of CCR5delta32 in healthy and sick covid populations as the Brazil study did.

But what really settles the argument is the frequency of covid in the double mutants. Zero out of 294 patients in the Brazil study. Probablity of that result is 5.2% if 1% of the population is homozygous.