Today, the U.S. Food and Drug Administration (FDA) approved lenacapavir for the prevention of HIV—ushering in a new era in viral prevention. Developed by Gilead Sciences, this long-acting therapy requires just two injections per year and provides near-complete protection against HIV infection.
Lenacapavir works by targeting the HIV capsid proteins, which play a crucial role in the virus’s ability to invade and replicate within human immune cells. This breakthrough stems from years of research into the structure and function of the capsid.
HIV typically enters immune cells by using its envelope proteins—gp120 and gp41—to bind to surface receptors such as CXCR4 /CCR5. Once attached, the virus can penetrate the host cell and hijack its genetic machinery. The similar mechanisms are used by other viruses too. For example, SARS-CoV-2, the virus responsible for COVID-19, uses its spike proteins (S1 and S2) to enter human lung cells. These parallels suggest promising avenues for broader antiviral strategies that target viral entry points.
The approval of lenacapavir highlights the potential of capsid inhibitors as a powerful new class of antiviral drugs—not only for HIV but for other viruses such as influenza and avian flu. This marks a hopeful step forward in the global fight against viral diseases.