As a result of collaborative efforts of the staff members of the Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia, the Armenian Bone Marrow Donor Registry Charitable Trust  and  "ClinSoft" LLC, an association between common HLA-C * 04:01 allele and COVID-19 severity has been revealed in Armenians.

Corroborating a significant role of other factors, such as male sex and an advanced age, in the severity of the disease in the Armenian population, the results of the study strongly suggest that HLA-C*04:01 allelic-load contributes to the risk for the severe COVID-19 independently from age and other HLA variables.

"The absence of the HLA-C*04:01 variant predicts asymptomatic course of the disease for the majority of the population, while homozygote carriage of this variant disrupts the recognition of coronavirus by the immune-competent cells and impedes the formation of an adequate immune response in time. The delay period is used by coronavirus for multiplication, which contributes to the severe course of the disease," said Karine Mayilyan, a senior scientific staff of the Laboratory of Human Genomics of the Institute of Molecular Biology of NAS RA.

"The research included more than 3,000 DNA sequences of Armenian residents. Based on HLA-C genotype and demographic variables, an algorithm has been developed for assessing the risk of the severe course of the disease, which can serve as a prognostic application in the medical practice" said Anahit Hovhannisyan, a scientific staff of the Laboratory of Evolutionary Genomics of the Institute of Molecular Biology of NAS RA.

"From the point of view of public health, this important result justifies the necessity for primary vaccination of the target group against COVID-19, which will prevent the severe course of the disease," said Arsen Arakelyan, the Director of the Institute.

The results of the study were published in the prestigious scientific journal "Frontiers in Immunology" (Hovhannisyan A, Madelian V, Avagyan S, Nazaretyan M, Hyussyan A, Sirunyan A, Arakelyan R, Manukyan Z, Yepiskoposyan L, Mayilyan KR, Jordan F. HLA-C * 04:01 Affects HLA Class I Heterozygosity and Predicted Affinity to SARS-CoV-2 Peptides, and in Combination With Age and Sex of Armenian Patients Contributes to COVID-19 Severity.Front Immunol.2022 Feb 3; 13: 769900.doi: 10.3389 /fimmu.2022.769900).