Sex and prior exposure jointly shape innate immune responses to a live herpesvirus vaccine

Background

Both sex and prior exposure to pathogens are known to influence responses to immune challenges, but their combined effects are not well established in humans, particularly in early innate responses critical for shaping subsequent outcomes.

Methods

We employed systems immunology approaches to study responses to a replication-defective, herpes simplex virus (HSV) 2 vaccine in men and women either naive or previously exposed to HSV.

Results

Blood transcriptomic and cell population profiling showed substantial changes on day 1 after vaccination, but the responses depended on sex and whether the vaccinee was naive or previously exposed to HSV. The magnitude of early transcriptional responses was greatest in HSV naive women where type I interferon (IFN) signatures were prominent and associated negatively with vaccine-induced neutralizing antibody titers, suggesting that a strong early antiviral response reduced the uptake of this replication-defective virus vaccine. While HSV seronegative vaccine recipients had upregulation of gene sets in type I IFN (IFN-α/β) responses, HSV2 seropositive vaccine recipients tended to have responses focused more on type II IFN (IFN-γ) genes.

Conclusions

These results together show that prior exposure and sex interact to shape early innate responses that then impact subsequent adaptive immune phenotypes.

Funding

Intramural Research Program of the NIH, the National Institute of Allergy and Infectious Diseases, and other institutes supporting the Trans-NIH Center for Human Immunology, Autoimmunity, and Inflammation. The vaccine trial was supported through a clinical trial agreement between the National Institute of Allergy and Infectious Diseases and Sanofi Pasteur. Clinical trial number: NCT01915212.

A Replication-Defective Herpes Simplex Virus (HSV)-2 Vaccine, HSV529, is Safe and Well-Tolerated in Adults with or without HSV Infection and Induces Significant HSV-2-Specific Antibody Responses in HSV Seronegative Individuals

Background

We conducted a phase 1, randomized, double-blind, placebo-controlled trial of a replication-defective HSV-2 vaccine, HSV529 (deleted for UL5 and UL29), in 60 healthy adults aged 18 to 40 years.

Methods

Subjects were enrolled in groups of 20 from 3 serogroups: HSV1+ or 
-/HSV2+ (group 1), HSV1+/HSV2– (group 2), and HSV1-/HSV2– (group 3). At months 0, 1, and 6, 15 subjects in each group received HSV529 intramuscularly and 5 subjects received placebo. The primary endpoint was the frequency of solicited injection site and systemic reactions from day 0 to 7 after each vaccination and unsolicited adverse events up to 6 months after the last dose.

Results

89% of vaccine recipients experienced a mild to moderate solicited injection site reaction vs. 47% of placebo recipients (P = 0.006, 95% CI 0.129, 0.676) that did not preclude additional doses. 64% of vaccine recipients experienced solicited systemic reactions vs. 53% of placebo recipients (P = 0.44, 95% CI -0.179, 0.402). Two serious adverse events occurred in 2 participants and were assessed as unrelated to HSV529 administration. Serum neutralizing antibody titers significantly increased from baseline after 3 doses of HSV529 compared with placebo in group 3 only (P < 0.001). This increase persisted up to 6 months after the third dose of vaccine (P < 0.001). Serum and vaginal antibodies to HSV2 glycoprotein D (gD) also significantly increased after 3 doses of vaccine in group 3 subjects (P < 0.001 and P = 0.012, respectively). The mean vaginal gD titer after 3 doses was about one-third of the mean serum gD titer. In addition, the vaccine induced significant levels of HSV2-specific antibody dependent cellular cytotoxicity (ADCC) after 3 doses in group 3 subjects compared with placebo (P < 0.001). Vaccine-induced CD4 T-cell responses were detected in 46%, 27%, and 36% of subjects in groups 1, 2, and 3, respectively, one month after the third dose of vaccine. CD8 T-cell responses were detected in 8%, 18%, and 14% of subjects in groups 1, 2, and 3, respectively, at the same time point.

Conclusion

The HSV529 vaccine was safe, well-tolerated, and immunogenic, eliciting significant neutralizing, gD, and ADCC-mediating antibodies, and modest cellular immune responses in HSV seronegative individuals. NCT01915212

Disclosures

L. Dropulic, sanofi pasteur: Collaborator, Research support; K. Wang, sanofi pasteur: Collaborator, Research support; M. Oestreich, sanofi pasteur: Collaborator, Research support; H. Pietz, sanofi pasteur: Collaborator, Research support; D. Garabedian, sanofi pasteur: Collaborator, Research support; K. Dowdell, sanofi pasteur: Collaborator, Research support; H. Nguyen, sanofi pasteur: Collaborator, Research support; K. Laing, sanofi pasteur: Research Contractor, payment for conducting T cell assays; D. Koelle, sanofi pasteur: Research Contractor, payment for conducting T cell assays; A. Azose, sanofi pasteur: Research Contractor, Payment for conducting T cell assays; A. Chen, sanofi pasteur: Employee, Salary; L. J. Chang, sanofi pasteur: Employee, Salary; S. Phogat, sanofi pasteur: Employee, Salary