ERVW-1 and infection: For the 25 patient sera samples that were able to neutralize both of the sensitive viruses, only two (NJ006 and NJ035), both from patients with less than 1-year infection, could not neutralize any other primary Env pseudotyped viruses, suggesting that once NAb are elicited, sera can neutralize not just the sensitive viruses, but also additional primary Env viruses.