HIV Vaccine

Disease Burden And Epidemiological Need

40.8 million individuals living with human immunodeficiency virus in 2024.
1.3 million new infections documented globally in 2024.
120,000 infants acquired infection in 2024.
Postnatal breastfeeding period accounts for 50 percent of infant acquisitions.
Sustainable pandemic control requires novel preventive tools beyond antiretroviral pre-exposure prophylaxis.

Barrier	Pathogenic Mechanism
Genetic diversity	Mutation rate of 3.4 x 10^-5 per base creates high variability within populations.
Glycan shield	Dense sugar molecules mask neutralizing viral targets on envelope trimer.
Rapid integration	Virus stealthily attacks and inserts genetic blueprint into host immune cells.
Absent natural model	No documented natural clearance of infection deprives researchers of protective immunity blueprint.

Strategy	Immunological Mechanism
Germline targeting	Sequential engineered immunogens coach B-cells to produce broadly neutralizing antibodies (bnAbs)
Messenger RNA platforms	Delivers stabilized envelope trimers or mosaic antigens via lipid nanoparticles.
T-cell vaccines	Elicit cytotoxic T-lymphocyte responses using adenovirus vectors to clear intracellular pathogen.
Passive prophylaxis	Direct infusion of engineered broadly neutralizing antibodies with extended half-life.

Candidate / Trial	Platform	Mechanism / Target
IAVI G002 / G003	mRNA	Prime-boost strategy targeting VRC01-class bnAbs.
HVTN 302	mRNA	Tests stabilized HIV envelope trimers (BG505 MD39.3).
VIR-1388	CMV Vector	Uses Cytomegalovirus vector to induce persistent T-cell responses.
PrEP-Vacc	Combination	DNA vaccine + protein boost combined with oral PrEP.

Passive Immunization: Direct infusion of lab-made bnAbs (e.g., VRC01, PGT121) as an alternative to active vaccination.
Mucosal Immunity: Developing nasal or oral vaccines to block entry at the site of infection.
Adjuvant Innovation: Using novel chemical compounds to enhance the magnitude and duration of the T-cell and B-cell response.