LEAP Publications

Important progress has been achieved in the development of long-acting antiviral formulations for the prevention and treatment of HIV. Replacing daily oral regimens with long-acting ones, administered as infrequent injections or implantable devices, could greatly simplify and improve HIV prevention and treatment. The successful uptake of long-acting injectable formulations for treatment of schizophrenia, and the use of implantable formulations of contraceptive medications by millions of women, suggests that such formulations would be well accepted.

Great advances over the past three decades have led to the development and optimization of antiretrovirals that are highly potent, safe, and well tolerated. There is, however, no currently available ARV drug or formulation with a dosing frequency less than once daily. Nonadherence to daily oral medication remains the most significant barrier to long-term suppression of HIV replication and prevention of the emergence of drug-resistant virus.

In 2017, an estimated 10·1 million women and 1·8 million children younger than 15 years worldwide were living with HIV.1 Women continue to account for a disproportionate percentage of new HIV infections among adults (aged 15 years and older) in sub-Saharan Africa: this population represented 59% of the 18 million new adult HIV infections in 2017. Meanwhile, the number of adolescents (aged 10–19 as defined by WHO) living with HIV has increased.2 Daily oral antiretroviral therapy (ART) has had a substantial impact on treatment and prevention of HIV, but inadequate or incomplete adherence, leading to treatment failure and drug resistance, are major obstacles.

Tuberculosis (TB) has surpassed HIV to become the leading infectious killer of adults globally, causing almost 2 million deaths annually (1). Although this airborne disease has been treatable since 1948, global rates of TB have dropped less than 2% per year; an estimated 10 million incident cases continue to occur annually, including 1 million in children. Although transmission of active disease is an important driver of the epidemic, the seedbed that feeds the epidemic is the more than 2 billion people estimated to have TB infection, 5% to 10% of whom will progress to active disease during their lifetime. Although any successful strategy aimed at TB elimination needs to address this reservoir of TB infection worldwide, much remains to be understood about host and pathogen factors that can be used to identify increased risk for progression to disease and intervened on to prevent progression from occurring.