The 85-90% is when at least 12 weeks have passed since a concerning encounter. The Mayo Clinic stopped offering this test in 2019 and Quest and LabCorp will stop offering it by the end of 2022.
We used to see very few false positives on the HSV 1 IgG, everyone above 3.0 confirmed, but now I am seeing more – I don’t have statistics on this, just anecdotal comments.
I’m not sure how many people don’t develop antibody to glycoportein G but I don’t think it is quite common.
The number of false negatives on the IgG test for HSV 1 probably remains the same long term though generally, people who do the IgG and then come to me for the western blot don’t repeat it again in 6 months. But I would guess that it stays the same as I have seen several people retest years later and it is the same