I believe you can see my previous question and the situation I had. I finished PEP and 5 weeks after my last dose of  PEP had a 3rd generation Insti test which is widely used in Canada and UK. It only checks for antibodies via needle poke and small blood collected. It was negative at 5 weeks. Few questions.

1. Is the Insti 3rd generation the same as a 3rd generation lab test in terms of window period and accuracy?

2. I read that PEP will further delay the window period does that mean the testing window will not start after last dose of PEP but much later?

3. If I had negative result via a 3rd generation Insti POC test what is the accuracy percentage. I read on a few sites such HIV I-base and Vancouver Health that it’s 95% accurate at 5 weeks. Do you agree with this as the internet has a lot of misleading information. But since I was on PEP when do I actually start counting these 5 weeks?

4. Should I still have another test using a 4th generation at 6 weeks or at 3 months with another 3rd generation Insti?

1. Yes, Insti is just as reliable as any other third generation HIV blood test.

2,3. Most experts agree that with PEP, the window period starts after the last dose of drug. There are no data on the precise accuracy of testing at various intervals. However, that's for a good reason:  almost nobody who takes PEP turns out to be HIV infected, so it is difficult to do research to calculate test accuracy. 

4. Most experts would advise a final AgAb (4th generation) blood test about 6 weeks after the last PEP dose. Presuming you do that, your result will be negative. Most experts see no need for a test at 3 months, especially in a zero risk situation like your own -- and that certainly is my view.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Would my 3rd generation Insti test at 5 weeks give no indication of status? Was it a wasted test?