Hi, a 4th gen hiv test would be somewhat accurate at 14 days post exposure? since p24 peaks around that day, and the prevalence of hiv-2 in the us is null, would be a good indicator?

15-20 days is approximate time to positivity so 14 days is a little bit early. 4th generation test done after 3 weeks of exposure is recommended.

If the result is positive it is accurate. A negative result warrants repeat testing at 6 weeks after exposure. Visit this site for info: HIV test window periods https://www.cdc.gov/hiv/basics/hiv-testing/test-types.html