Zoster vaccine recommendations: the importance of using a clinically valid correlate of protection

Immunogenicity and influence on disease activity of recombinant zoster vaccine in patients with rheumatoid arthritis treated with DMARDs

OBJECTIVES

This study aimed to determine the immunogenicity and the influence on disease activity of an adjuvanted recombinant varicella-zoster virus (VZV) subunit vaccine (RZV) in patients with rheumatoid arthritis (RA) treated with disease-modifying antirheumatic drugs (DMARDs).

METHODS

This prospective longitudinal study enrolled 53 patients with RA (aged ≥50 years) treated with DMARDs (conventional synthetic (cs)DMARDs 20, biological (b)DMARDs 23 and targeted synthetic (ts)DMARDs 10) and 10 control individuals. The participants received two intramuscular RZV 2 months apart. VZV-specific CD4+ T cell responses (cell-mediated immunity; CMI) and IgG antibody responses (humoral immunity; HI) were assessed at 0 and 3 months after the first RZV administration using flow cytometry and enzyme immunoassay, respectively. Disease activity (Disease Activity Score 28-C reactive protein and Clinical Disease Activity Index), flares and adverse events were monitored for 6 months after the first vaccination.

RESULTS

VZV-specific CMI and HI significantly increased in the three DMARDs-treated patients with RA after RZV administration compared with the corresponding prevaccination values (p<0.001-0.014), and the magnitudes and fold-increases of those responses were not significantly different among the three DMARDs-treated patients with RA. Furthermore, the vaccine response rates of CMI and HI were not significantly different between csDMARDs-treated patients and b-DMARDs or ts-DMARDs-treated patients. Meanwhile, no significant increases in disease activity indices or adverse events were observed in these patients during the 6-month follow-up period after the first vaccination. RZV-induced RA flares occurred in two patients (3.8%) but were mild and controllable.

CONCLUSION

RZV is robustly immunogenic and has a clinically acceptable safety profile in elderly patients with RA receiving DMARDs.

Recombinant Zoster Vaccine (Shingrix): Real-World Effectiveness in the First 2 Years Post-Licensure

Background

Shingrix (recombinant zoster vaccine) was licensed to prevent herpes zoster, dispensed as 2 doses given 2–6 months apart among adults aged ≥50 years. Clinical trials yielded efficacy of &gt;90% for confirmed herpes zoster, but post-market performance has not been evaluated. Efficacy of a single dose and a delayed second dose and efficacy among persons with autoimmune or immunosuppressive conditions have not been studied. We aimed to assess post-market vaccine effectiveness of Shingrix.

Methods

We conducted a cohort study among Medicare Part D community-dwelling beneficiaries aged &gt;65 years. Herpes zoster was identified using a medical office visit diagnosis with treatment, and postherpetic neuralgia was identified using a validated algorithm. We used inverse probability of treatment weighting to improve cohort balance and marginal structural models to estimate hazard ratios.

Results

We found a vaccine effectiveness of 70.1% (95% confidence interval [CI], 68.6–71.5) and 56.9% (95% CI, 55.0–58.8) for 2 and 1 doses, respectively. The 2-dose vaccine effectiveness was not significantly lower for beneficiaries aged &gt;80 years, for second doses received at ≥180 days, or for individuals with autoimmune conditions. The vaccine was also effective among individuals with immunosuppressive conditions. Two-dose vaccine effectiveness against postherpetic neuralgia was 76.0% (95% CI, 68.4–81.8).

Conclusions

This large real-world observational study of the effectiveness of Shingrix demonstrates the benefit of completing the 2-dose regimen. Second doses administered beyond the recommended 6 months did not impair effectiveness. Our effectiveness estimates were lower than the clinical trials estimates, likely due to differences in outcome specificity.

Immune Responses to a Recombinant Glycoprotein E Herpes Zoster Vaccine in Adults Aged 50 Years or Older

Background

The herpes zoster subunit vaccine (HZ/su), consisting of varicella-zoster virus glycoprotein E (gE) and AS01_B Adjuvant System, was highly efficacious in preventing herpes zoster in the ZOE-50 and ZOE-70 trials. We present immunogenicity results from those trials.

Methods

Participants (ZOE-50: ≥50; ZOE-70: ≥70 years of age) received 2 doses of HZ/su or placebo, 2 months apart. Serum anti-gE antibodies and CD4 T cells expressing ≥2 of 4 activation markers assessed (CD4²⁺) after stimulation with gE-peptides were measured in subcohorts for humoral (n = 3293) and cell-mediated (n = 466) immunogenicity.

Results

After vaccination, 97.8% of HZ/su and 2.0% of placebo recipients showed a humoral response. Geometric mean anti-gE antibody concentrations increased 39.1-fold and 8.3-fold over baseline in HZ/su recipients at 1 and 36 months post-dose 2, respectively. A gE-specific CD4²⁺ T-cell response was shown in 93.3% of HZ/su and 0% of placebo recipients. Median CD4²⁺ T-cell frequencies increased 24.6-fold (1 month) and 7.9-fold (36 months) over baseline in HZ/su recipients and remained ≥5.6-fold above baseline in all age groups at 36 months. The proportion of CD4 T cells expressing all 4 activation markers increased over time in all age groups.

Conclusions

Most HZ/su recipients developed robust immune responses persisting for 3 years following vaccination.

Clinical Trials Registration

NCT01165177; NCT01165229.

Understanding the immunology of Shingrix, a recombinant glycoprotein E adjuvanted herpes zoster vaccine

Herpes zoster is common in older and immune suppressed persons due to diminished VZV-specific cellular immunity. A recombinant herpes zoster vaccine (RZV) consisting of a single VZV glycoprotein and an adjuvant system stimulates robust and persistent VZV-specific antibody and CD4+ T cell responses in these high-risk populations. VZV-specific immune responses induced by RZV, including the generation of polyfunctional T cells, are driven by the synergistic actions of the components of the vaccine adjuvant system. RZV provides unprecedented protection against herpes zoster in older adults regardless of age at vaccination and is efficacious in immune suppressed populations. Adjuvanted subunit antigens may represent a general strategy for vaccines in the elderly and other individuals typically considered immunologically resistant to vaccination.

Real-World Evidence for Regulatory Decisions: Concomitant Administration of Zoster Vaccine Live and Pneumococcal Polysaccharide Vaccine

The US Food and Drug Administration is charged with expanding the use of real-world evidence for regulatory decisions. As a test case for real-world evidence to support regulatory decisions, we present the scenario of concomitant vaccination with zoster vaccine live (ZVL) and 23-valent pneumococcal polysaccharide vaccine (PPSV23). The prescribing information states that these vaccines should not be given concurrently, based on a small trial using varicella zoster virus antibody levels as a correlate of ZVL efficacy, even though ZVL protects against herpes zoster via cell-mediated immunity. We conducted an observational cohort study involving more than 35,000 members of Kaiser Permanente Southern California receiving concomitant ZVL and PPSV23 versus PPSV23 prior to ZVL. Occurrence of herpes zoster was assessed through electronic health records from January 1, 2007, to June 30, 2016. The adjusted hazard ratio comparing incidence rates of herpes zoster in the concomitant vaccination cohort and the prior vaccination cohort was 1.04 (95% confidence interval: 0.92, 1.16). This real-world evidence study provides direct evidence for a lack of vaccine interference, relying on herpes zoster occurrence rather than an intermediate marker of immunity. Real-world evidence is essential for regulators and policy makers in addressing evidentiary gaps regarding safety, effectiveness, compliance, and vaccine interactions for the new recombinant zoster vaccine.

Shingles vaccination: background and advice for community nurses

Shingles (or zoster) is a reactivation of an existing varicella-zoster virus (VZV) infection. During the initial infection, VZV causes a systemic disease known as varicella or chickenpox, and this initial infection normally occurs early in childhood in the absence of routine vaccination. Although varicella is normally a mild disease, shingles is associated with significant morbidity and some mortality, particularly in older people. The most significant severe consequence is post-herpetic neuralgia. There is an effective vaccine available for this, known as Zostavax, which is a live-attenuated VZV vaccine. Guidelines in the UK recommend that this is offered to everyone when they become 70 years of age, plus those aged 79 years as part of a catch-up campaign, with those between these ages not being eligible. It is important for all health-care professionals, including district and community nurses, to proactively promote this vaccine, so that those eligible can make an informed decision about whether to receive it.

A phase 1/2 clinical trial evaluating safety and immunogenicity of a varicella zoster glycoprotein e subunit vaccine candidate in young and older adults

BACKGROUND

An adjuvanted recombinant varicella zoster virus (VZV) subunit vaccine is being developed for the prevention of herpes zoster and its complications.

METHODS

In a phase I/II, open-label, randomized, parallel-group study, older adults (50-70 years) received 2 doses 2 months apart of an adjuvanted recombinant glycoprotein E vaccine (HZ/su; n = 45), a live attenuated Oka strain VZV vaccine (OKA; n = 45), or HZ/su and OKA administered concomitantly (n = 45). To evaluate safety prior to administration in older adults, young adults (18-30 years) were vaccinated with 2 doses 2 months apart of HZ/su (n = 10) or OKA (n = 10). Safety and immunogenicity were assessed up to 42 months for older adults immunized with HZ/su and up to 12 months for all others.

RESULTS

Few grade 3 events and no severe adverse events were reported. Fatigue, myalgia, headache, and injection site pain were the most common solicited reactions for HZ/su and occurred more frequently than with OKA. CD4(+) T-cell and humoral immune responses were much higher with HZ/su than with OKA and remained elevated until 42 months. Addition of OKA to HZ/su did not increase immunogenicity.

CONCLUSIONS

In this study, HZ/su adjuvanted subunit vaccine was well tolerated and more immunogenic than a live attenuated VZV vaccine. Clinical Trial registration. NCT00492648 and NCT00492648.

Immune senescence and vaccines to prevent herpes zoster in older persons

Varicella-zoster virus (VZV) T-cell-mediated immunity (VZV-CMI) in older persons prevents latent VZV in sensory neurons from reactivating to cause herpes zoster. VZV-CMI declines greatly with aging, but can be restored by the licensed zoster vaccine. However, the vaccine-induced boost in VZV-CMI (which determines the efficacy of the vaccine) is a function of the age of the vaccinee, and the duration of this boost wanes with time. Both factors influence the value of this vaccine. To understand these aging effects, limited information about the phenotypic and functional differences in VZV-CMI in old and young persons are reviewed, as well as the reversal of these differences by vaccination. Based on information from these studies some potential approaches to improving prevention of herpes zoster are discussed.