Viral Diversity

The current HIV viral panels are outdated, poorly characterized and do not represent the diversity of viral strains observed worldwide.  Furthermore, as clades have spread to new geographic regions, mutated and recombined, new circulating recombinant forms (CRFs) of the virus have emerged.  This has necessitated the development of a well-characterized, global HIV isolate repository.  To this end, one of the goals of EQAPOL is to establish and characterize unique clade-specific HIV virus panels. 

The goal of the program is to establish a set of fully characterized viruses from early acute HIV infections that are consistent with the degree of viral evolution present globally for the following applications:

  • Developing new assays
  • Validating assay platforms
  • Assisting regulators to evaluate test kits
  • Monitoring HIV drug resistance
  • Informing vaccine development

Through partnerships with the Blood Systems Research Institute and other collaborating sites, samples are gathered from newly-identified HIV-infected individuals with rare, unique or difficult to identify isolates, which are then be propagated to high titer in culture. To increase geographic diversity of the panel, previously cultured HIV has been gathered for further propagation by EQAPOL. All virus sources are cultured to high titer/high volume and then stored as neat culture supernatant, as well as spiked into defibrinated plasma at three different concentrations. Viruses are evaluated, characterized, and fully sequenced before adding them to a central repository where they will be available to the research community. For the EQAPOL Viral Diversity Program, 50 new viruses are cultured to high titer/high volume each year.

The current EQAPOL Viral Diversity panel includes over 322 viral isolates representing 6 subtypes (A, B, C, D, F, G), 2 sub-subtypes (F1, F2), 10 circulating recombinant forms (CRFs) (01, 02, 04, 11, 14, 22, 24, 47, 59, 70), 75 unique recombinant forms (URFs), 3 HIV-2, 1 group P, and 5 group O viruses from 37 countries as shown in the map below. More information about our other specialized panels is available here.

Viral Diversity samples are available to NIAID-approved laboratories.  Products created for the EQAPOL Viral Diversity Program are available to order. These products can be requested via a secure, web-based application ( Laboratories wishing to participate in the program should contact us.