Dynavax's Z-1018 heads into head-to-head shingles data versus Shingrix
Part 1 showed immune responses comparable to Shingrix with favorable tolerability; Part 2 in adults 70 and older will test non-inferiority against the market leader.
Executive Summary
- Dynavax is moving from an already-reported positive immunogenicity signal into a harder confirmatory test: reproducing Shingrix-comparable immune responses in the age group at the highest risk of shingles.
- The trial's target enrollment grew and its completion timeline extended as the study advanced from an initial dose-finding stage into a larger, randomized comparison against the approved vaccine, a sequencing change rather than a delay driven by a problem.
- Z-1018 enters a field where the approved standard sits alongside several earlier-stage candidates chasing the same viral antigen, meaning Dynavax's asset must differentiate on tolerability or convenience rather than claim an unproven mechanism.
- The upcoming data will show whether the vaccine response rates and tolerability profile seen in the initial dose-ranging population hold up in adults 70 and older, the group in which non-inferiority to Shingrix is the explicit design objective.
The stake
Dynavax Technologies Corporation (Nasdaq: DVAX) is developing Z-1018 as a shingles vaccine intended to compete with Shingrix, the recombinant subunit vaccine that is the standard of care for herpes zoster prevention in older adults. The Phase 1/2 trial, registered as NCT06569823, is testing Z-1018 against Shingrix in a randomized, observer-blinded, active-controlled design. Part 1 enrolled adults aged 50 through 69 across a range of antigen doses and adjuvant combinations; Part 2, now underway in Australia and New Zealand, enrolls adults 70 and older, the population at the highest risk of shingles. NCT06569823+1Safety and Immunogenicity of an Investigational Herpes Zoster Vaccine (Z-1018) Compared to Shingrix® in Healthy Adults 50 Years of Age and OverNCT06569823Dynavax Presents Positive Topline Data from Part 1 of Phase 1/2 Trial for Shingles Vaccine Candidate at IDWeek 2025 and Announces Initiation of Part 2 of TrialOct 21, 2025
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
What Part 1 showed
Dynavax reported Part 1 topline data at IDWeek 2025, saying Z-1018 elicited anti-gE IgG antibody responses and gE-specific CD4+ T-cell responses, with vaccine response rates described as comparable to Shingrix four weeks after the second dose, alongside a favorable tolerability profile. The company also reported polyfunctional CD4+ T-cell responses across multiple activation markers, and selected 100 mcg of gE antigen with CpG 1018 plus alum, dosed at weeks 0 and 8, as the regimen advancing into Part 2. Dynavax's chief medical officer, Robert Janssen, said the data "reinforces our belief that Z-1018 has the potential to deliver best-in-class performance by combining robust immunogenicity with a differentiated tolerability profile". DynavaxDynavax Presents Positive Topline Data from Part 1 of Phase 1/2 Trial for Shingles Vaccine Candidate at IDWeek 2025 and Announces Initiation of Part 2 of TrialOct 21, 2025
The confirmatory test
Part 2 is designed to demonstrate non-inferiority to Shingrix on select immunogenicity measures in the 70-and-older population, according to the company's own framing of the study's regulatory plans. This is a bridging test rather than a novel-mechanism trial: Z-1018 targets the same viral glycoprotein E antigen that underlies the approved comparator, so the readout must reproduce the immunogenicity and tolerability band Part 1 already established, in an older, more immunosenescent population, rather than establish a new therapeutic hypothesis. DynavaxDynavax Presents Positive Topline Data from Part 1 of Phase 1/2 Trial for Shingles Vaccine Candidate at IDWeek 2025 and Announces Initiation of Part 2 of TrialOct 21, 2025
Enrollment and timeline shift
The trial's registered enrollment target rose from 440 to 764 participants and its primary completion date moved from September 2026 to November 2027, both changes recorded in November 2025 as Part 2 began enrolling. That combination reflects the study's expansion into a second, larger comparative stage rather than a sign of operational trouble: an enrollment increase of this kind reads as typical study-design progression rather than distress. The trial moved to Active, not recruiting status in May 2026, consistent with enrollment reaching its target ahead of the pending readout. NCT06569823Safety and Immunogenicity of an Investigational Herpes Zoster Vaccine (Z-1018) Compared to Shingrix® in Healthy Adults 50 Years of Age and OverNCT06569823
The competitive field
The herpes zoster vaccine field is built around the shared gE antigen that Shingrix, Z-1018, and several other candidates all target, including Immorna Biotherapeutics' JCXH-105, Moderna's mRNA-1468, and CHA Vaccine Institute's CVI-VZV-001, all in Phase 1 or Phase 2 testing against the same antigen. No candidate in that group has yet produced a resolved regulatory outcome to benchmark against Shingrix's approved status, so Z-1018's Part 2 result will be read against the approved vaccine's own established immunogenicity and tolerability profile rather than against a track record of rival readouts.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.