Breadth and Functionality of Varicella-Zoster Virus Glycoprotein-Specific Antibodies Identified after Zostavax Vaccination in Humans

Abstract

Herpes zoster (HZ) (shingles) is the clinical manifestation of varicella-zoster virus (VZV) reactivation. HZ typically develops as people age, due to decreased cell-mediated immunity. However, the importance of antibodies for immunity against HZ prevention remains to be understood. The goal of this study was to examine the breadth and functionality of VZV-specific antibodies after vaccination with a live attenuated HZ vaccine (Zostavax). Direct enumeration of VZV-specific antibody-secreting cells (ASCs) via enzyme-linked immunosorbent spot assay (ELISPOT assay) showed that Zostavax can induce both IgG and IgA ASCs 7 days after vaccination but not IgM ASCs. The VZV-specific ASCs range from 33 to 55% of the total IgG ASCs. Twenty-five human VZV-specific monoclonal antibodies (MAbs) were cloned and characterized from single-cell-sorted ASCs of five subjects (>60 years old) who received Zostavax. These MAbs had an average of ∼20 somatic hypermutations per VH gene, similar to those seen after seasonal influenza vaccination. Fifteen of the 25 MAbs were gE specific, whereas the remaining MAbs were gB, gH, or gI specific. The most potent neutralizing antibodies were gH specific and were also able to inhibit cell-to-cell spread of the virus Most gE-specific MAbs were able to neutralize VZV, but they required the presence of complement and were unable to block cell-to-cell spread. These data indicate that Zostavax induces a memory B cell recall response characterized by anti-gE> anti-gI > anti-gB > anti-gH antibodies. While antibodies to gH could be involved in limiting the spread of VZV upon reactivation, the contribution of anti-gE antibodies toward protective immunity after Zostavax needs further evaluation. Varicella-zoster virus (VZV) is the causative agent of chickenpox and shingles. Following infection with VZV, the virus becomes latent and resides in nerve cells. Age-related declines in immunity/immunosuppression can result in reactivation of this latent virus, causing shingles. It has been shown that waning T cell immunity correlates with an increased incidence of VZV reactivation. Interestingly, serum with high levels of VZV-specific antibodies (VariZIG; IV immunoglobulin) has been administered to high-risk populations, e.g., immunocompromised children, newborns, and pregnant women, after exposure to VZV and has shown some protection against chickenpox. However, the relative contribution of antibodies against individual surface glycoproteins toward protection from shingles in elderly/immunocompromised individuals has not been established. Here, we examined the breadth and functionality of VZV-specific antibodies after vaccination with the live attenuated VZV vaccine Zostavax in humans. This study will add to our understanding of the role of antibodies in protection against shingles.

Influence of immune aging on vaccine responses

“…Thus, although Zostavax appears to induce sufficient effector levels, the quality of this response is compromised with age, as is its ability to generate or maintain effective long-term memory T cells. Although Zostavax elicits vaccine-specific antibody production, 68 little is known about how age affects the memory B-cell responses.…”

Identification and characterization of CD4+ T cell epitopes after Shingrix vaccination

“…While studies have been conducted to assess the immunogenicity of different VZV proteins (24), and the immunological responses to VZV vaccinations have been described elsewhere (23,28,48,49), there is still little known regarding the epitopes recognized by T cells after VZV vaccination. Identifying immunogenic epitopes and designing tetramers specific to VZV epitopes will allow further characterization of the observed polyfunctional response in Shingrix vaccinees and may help establish correlates of protection for HZ patients.…”

The Adjuvanted Recombinant Zoster Vaccine in Adults Aged ≥65 Years Previously Vaccinated With a Live-Attenuated Herpes Zoster Vaccine

“…Anti-gE antibody GMCs were similar between previous ZVL recipients and ZVL-naive study participants at all time points, including before vaccination. Although the humoral response to ZVL is dominated by anti-gE antibodies [ 19 ], this similarity may be explained by the rapid waning of ZVL-induced humoral immunity. When measured by glycoprotein-based enzyme-linked immunosorbent assay, VZV-specific antibody titers 12 months after ZVL administration were indeed similar to prevaccination titers [ 20 ].…”