Concerning HERV-W activation, though it was found to correlate the severity of the first COVID-19 episode with all successive variants and to represent 100% of most severe cases, this activation along with the detection of the HERV-W ENV protein in serum or on blood lymphocytes was nonetheless detected in a significant percentage of patients with milder COVID-19 [10, 11, 33]. Here, ERVW-1 is linked to COVID-19.