A group from Department of Transplantation, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico, etc. has reported about protective HLA alleles against COVID-19.
In this pilot study in Tapachula, Chiapas México, the frequency of the allele HLA-A*68 is diminished in patients with severe disease and who had a fatal outcome. HLA-A*68 is an ancestral allele present in high frequencies in indigenous ancestral populations in Mexico, and the highest frequency is presented by the Teenek population, Yucatan Merida, and Yucatan rural inhabitants. The presence of protective alleles like HLA-A*68 could explain a little bit why this locality has been one of the least affected throughout Mexico, presenting low incidence rates of COVID-19.
On the other hand, the HLA-A*01 allele was associated with a fatal outcome.