Prime, pull, keep: a new playbook for therapeutic herpes vaccines

For about a century, therapeutic herpes vaccines have mostly tried to raise antibodies in the blood, and none has given strong, lasting protection against recurrences. This review in Vaccines, from Lbachir BenMohamed’s lab at the University of California, Irvine, argues for a different focus: T cells stationed where the virus actually reactivates.

The three steps

• Prime: train CD4+ and CD8+ T cells using fragments of the virus (“asymptomatic” epitopes) that the authors link to protection in people who rarely have symptoms.
• Pull: use signaling molecules called chemokines, such as CXCL11, to draw those T cells into the infected tissues.
• Keep: use survival signals (IL‑2, IL‑7, IL‑15) or mucosal chemokines (CXCL17, CCL28) to keep the T cells there for longer.

Where the evidence stands

Prime/pull/keep vaccine candidates have reduced recurrent eye and genital herpes in preclinical animal models, including a 2025 study in rabbits engineered to carry a human immune gene. The review summarizes that work and outlines what is needed to move toward human trials.

What to keep in mind

This is a review, not a new clinical trial. It describes a promising research strategy that hasn’t yet been tested in people, and it was written by the group developing the approach.