World's First Herpes Zoster mRNA Vaccine Enters Phase III Clinical Trial: Abogen Biosciences Sets Global Pace

Abogen Biosciences is racing toward a shot—literally. The Suzhou-based biotech company last week launched a multicenter Phase III clinical trial for its lyophilized herpes zoster mRNA vaccine, code-named ABO1108. The move makes it the first herpes zoster mRNA vaccine anywhere in the world to reach this late stage of testing.

The milestone matters. Herpes zoster, commonly known as shingles, affects millions of older adults each year, causing painful rashes that can linger for months. Current vaccines require cold storage and multiple doses—logistical hurdles that limit uptake in many markets. An mRNA-based approach that's stable at standard refrigerator temperatures could change that calculus.

Lightning pace

Abogen has moved quickly. The company received regulatory approval to begin human trials in March 2025, launched Phase I testing two months later, and started Phase II by November. Just seven months after the first dose went into an arm, the company is enrolling patients in the pivotal Phase III study.

The accelerated timeline reflects both urgency and confidence. "We've compressed what typically takes years into months," the company has indicated in prior statements. The speed suggests Abogen believes it has a winner—and wants to prove it before competitors catch up.

The technology

ABO1108 uses a proprietary gE protein antigen designed through Abogen's protein structure platform. The vaccine incorporates the company's own base modification technology and lipid nanoparticle delivery system—similar to the approach used in COVID-19 mRNA vaccines but optimized for varicella-zoster virus.

A key differentiator: lyophilization. The freeze-dried formulation remains stable for more than two years at 2 to 8 degrees Celsius—the standard temperature of medical refrigerators. That's a practical advantage over existing shingles vaccines that require ultra-cold storage or have shorter shelf lives.

Early results

Phase I and II data gave Abogen reason to push forward. The vaccine showed good safety and tolerability across all age groups, with most adverse reactions classified as Grade 1 or 2—mild to moderate. No serious adverse events, no adverse events of special concern, and no deaths or life-threatening reactions were reported.

On immunogenicity, two doses generated comprehensive, high-level immune responses. The immune response patterns and core immunogenicity indicators were comparable to the already-marketed recombinant zoster vaccine, suggesting ABO1108 has the immunological foundation for strong clinical protection.

A crowded race

Abogen isn't alone in chasing the shingles market in China. At least a dozen other companies have herpes zoster mRNA vaccines in clinical development, including Sinovac, CSPC Pharmaceutical, Lifanda Bio, Anhui Zhifei Longcom, Yueda Pharma, Lanque Bio, Afarna Bio, Jiachen XiHai, Aim vaccine, Rongcan Bio/Shanghai Institute of Biological Products, Ruiji Bio, and Shenxin Bio.

But Abogen's lead is meaningful. In vaccine development, being first to Phase III often translates to being first to market—and first-mover advantage in a category where medical infrastructure and physician familiarity matter. The company's Phase III data could position ABO1108 as the first approved herpes zoster mRNA vaccine globally.

For now, the focus is on enrollment and results. If Phase III confirms the early signals, Abogen will have turned a quick development sprint into something rarer: a potential first-in-class approval.