Leopold Achengui Zekeng is an immunologist, microbiologist and global health advocate, currently serving as the Country Director of the Joint United Nations Programme on HIV and AIDS (UNAIDS) in Nigeria. With four decades of experience in HIV and AIDS Resource mobilization, leading and managing teams, mentoring and coaching, research, policy development, and international program implementation, he has contributed significantly to public health efforts across Sub-Saharan Africa.
In 1994, Zekeng and his research team in Cameroon identified a highly divergent strain of HIV-1, later designated MVP-5180. This strain exhibited unique genetic and immunologic properties that rendered it undetectable by most standard HIV tests at the time. Sequencing of its genome revealed that MVP-5180 shared only 65% genetic similarity with typical HIV-1 strains and 56% with HIV-2, placing it evolutionarily closer to the divergence point between HIV-1 and HIV-2.
Serological testing in Cameroon revealed that approximately 8% of HIV-positive individuals were reactive to MVP-5180 antigens. Along with another isolate from Cameroon (ANT-70), this strain was later classified as part of HIV-1 Group O (for "Outlier"), a distinct and previously unrecognized group of the Virus.
This discovery highlighted the significant genetic diversity of HIV in West Central Africa and had global implications for diagnostics, vaccine development, and epidemiological surveillance. Zekeng's work led to the redesign of diagnostic protocols to account for Group O and other non-M subtypes.
Zekeng has served as the UNAIDS Country Director or held an equivalent leadership role inÃÂ fiveÃÂ countries: