Will a 4th gen hiv test detect hiv-2 antigens? i had some exposures with an african man. last test at 18 week ag/ab.when will hiv 2 be conclusive ?

4th gen covers HIV2: The antibody component of the 4th generation HIV blood tests (for both HIV antibody and p24 antigen) detects HIV2 infection. The test is generally conclusive any time 4 weeks or more after exposure, and for sure conclusive at 18 weeks. No worries and no further testing needed. Best wishes and stay safe!

Yes: All 4th gen HIV serologic test approved by the CDC will detect HIV 1 and HIV 2 infection. If negative at 18 weeks, you most likely don't have HIV infection.