What is the difference?
3rd generation HIV rapid test detects only HIV antibodies in the blood, while 4rd generation HIV rapid test detects HIV antibodies and p24 antigen in the blood.
Why does it want to detect antigen?
Early detection is crucial in when checking for HIV. HIV-1 P24 antigen appears in the blood as early as 14 days after possible infection, by using this to determine whether a person has been infected, detection period is able to cut down to as early as 14 days(or 16 days average)after possible infection.
Is it accurate?
Based on a lab report by Institute of Alboratory Medicine, Cantonal on the new Alere HIV Combo, it detected all positive samples given to it.
The new Alere Combo HIV has been awarded World Health Organization (WHO) prequalification (as of July 2016).
About Alere HIV Combo
The new Alere HIV Combo is an improved 4th generation HIV RDT over the older 4th generation HIV RDT, the Alere Determine HIV-1/2 Ag/Ab Combo. Based on reports, positive samples missed by Alere Determine HIV-1/2 Ag/Ab Combo have been successfully identified by the new Alere HIV Combo.
More References:
https://www.journalofclinicalvirology.com/article/S1386-6532(17)30182-8/pdf
https://www.prnewswire.com/news-releases/alere-hiv-combo-test-receives-who-prequalification-300297301.html