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Avatar universal

Please Answer my questions , for clarification and peace of mind

just for clarification ....  (1) has anyone ever seen a negative combo test at 16 days turn to positive at 28 days ? (2) the internet has very confusing information , does p24 antigen peak at 14 to 16 days or somewhere between 20- 28 days ? (3) if a 28th day result on a combo test is conclusive , which means no hiv positive person would have a negative test at that point , wouldn't SURETY detection been at an earlier day and the 28th day is just a confirmation. please answer me ....
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Avatar universal
The p24 antigen peaks around week 3 from what I've read. ( It starts falling off after that and supposedly by week 6 it's gone).  A few days later, you get a IgM antibodies and at the end of the 4th week, you usually have p24, IgM, and IgG present.  

But this is a statistic.  Some people take a few days longer and some people take a few days less.

When you do a DUO test, at 28 days you can reasonably expectant that enough time has passed to statistically that all 3 will be present.  Moreover, the test is looking for all 3 things.  

This means to get a false reading, it would mean that all three things are there i.e. an infection, but the test failed to detect all 3.    

So by waiting the extra time, you're giving everything a chance to work and thus reduce the chance of missing something.  

If you rely strictly on a p24 at 2 weeks, then you're facing two things.  Variance in how a particular infection is going to behave in a particular human body and the possibility of a sample error for a test because it failed to detect p24.  

Be well
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Avatar universal
The test is too new and overall we are not involved in testing here.
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Avatar universal
ok so the result can change , has it ever been seen here on this forum ? and 16 days is just half the time of a conclusive test , i dont understand why is it said that the antigens strt falling off at week 4 but still NOT detectable at 2 weeks proceeding to 3 ? Lets be logical here... a person who have been actually infected would have had detectable antigens at least at a 16 day mark ????
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480448 tn?1426948538
14-16 days is a good indication, but it's not conclusive.  A negative at 14 days could indeed become a + at 28 days.  ANY neg along the way is a very good sign.

If you're testing with a DUO., 28 days is conclusive.  That simple.  Try not to read more into it than you need.
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