Antibodies against a critical part of the HIV gp120 protein cannot easily get to their target—the CD4 binding site.3D4MEDICAL / PHOTO RESEARCHERS, INC
The most immunogenic molecules on the surfaces of pathogens—the ones that elicit the strongest immune response—are often also the most variable. The influenza virus changes its surface proteins so rapidly that a different vaccine must be manufactured every year. However, the nonimmunogenic part of the surface proteins remains unchanged. To overcome this difficulty, researchers are employing a number of new approaches—from tinkering with the immune system to scouring viral genomes for proteins that are conserved across generations—in a quest to create so-called “universal” vaccines. With such vaccines, one jab for each pathogen will protect us from all current and future variations of each disease, and maybe even from different families of related pathogens. But why has it been difficult to create such vaccines, and what ...
