The immunogenicity and safety of live attenuated varicella-zoster virus vaccine in human immunodeficiency virus-infected children

Immunogenicity and safety of live attenuated and recombinant/inactivated varicella zoster vaccines in people living with HIV: A systematic review

Few papers focus their attention on VZV vaccination effectiveness among people living with HIV (PLWH). Flanking the live attenuated vaccine (VZL) available, a newly recombinant vaccine (RZV) was recently introduced and approved for HZ prevention among adults. PLWH represents a population on which a particular attention should be applied, in order to guarantee the vaccine efficacy and safety. We performed a literature search in USNLM, PubMed, PubMed Central, PMC and Cochrane Library. From all the publications found eligible, data were extracted and processed per population, vaccine type, immunogenicity and ADRs. The review of the 13 included studies shows that both RZV and VZL are immunogenic and have an acceptable safety profile in adults and children living with HIV. However, given the lack of research available about vaccine efficacy in preventing VZV and HZ in PLWH, additional studies need to be performed, in order to achieve a full completeness of data.

Living with HIV and Getting Vaccinated: A Narrative Review

After 40 years of its appearance, human immunodeficiency virus (HIV) infection remains a leading public health challenge worldwide. Since the introduction of antiretroviral treatment (ART), HIV infection has become a chronic condition, and people living with HIV could have life expectancies close to those of the general population. People with HIV often have an increased risk of infection or experience more severe morbidity following exposure to vaccine-preventable diseases. Nowadays, several vaccines are available against bacteria and viruses. However, national and international vaccination guidelines for people with HIV are heterogeneous, and not every vaccine is included. For these reasons, we aimed to perform a narrative review about the vaccinations available for adults living with HIV, reporting the most updated studies performed for each vaccine among this population. We performed a comprehensive literature search through electronic databases (Pubmed-MEDLINE and Embase) and search engines (Google Scholar). We included English peer-reviewed publications (articles and reviews) on HIV and vaccination. Despite widespread use and guideline recommendations, few vaccine trials have been conducted in people with HIV. In addition, not all vaccines are recommended for people with HIV, especially for those with low CD4 cells count. Clinicians should carefully collect the history of vaccinations and patients' acceptance and preferences and regularly check the presence of antibodies for vaccine-preventable pathogens.

Precision immunization: a new trend in human vaccination

Vaccination has been one of the major revolutions in the history of human health. Vaccination programs have targeted entire populations such as infants or elderly subjects as a matter of being efficient with time and resources. These general populations are heterogeneous in terms of factors such as ethnicity, health status, and socio-economics. Thus, there have been variations in the safety and effectiveness profiles of certain vaccinations according to current population-wide strategies. As the concept of precision medicine has been raised in recent years, many researchers have suggested that vaccines could be administered more precisely in terms of particular target populations, vaccine formulations, regimens, and dosage levels. This review addresses the concept and framework of precision immunization, summarizes recent and representative clinical trials of among specific populations, mentions important factors to be addressed in customizing vaccinations, and provides suggestions on the establishment of precision immunization with the goal of maximizing the effectiveness of vaccines in general.

Long-term Immune Response to Yellow Fever Vaccination in Human Immunodeficiency Virus (HIV)-Infected Individuals Depends on HIV RNA Suppression Status: Implications for Vaccination Schedule

Background

In human immunodeficiency virus (HIV)-infected individuals, the immune response over time to yellow fever vaccination (YFV) and the necessity for booster vaccination are not well understood.

Methods

We studied 247 participants of the Swiss HIV Cohort Study (SHCS) with a first YFV after HIV diagnosis and determined their immune responses at 1 year, 5 years, and 10 years postvaccination by yellow fever plaque reduction neutralization titers (PRNTs) in stored blood samples. A PRNT of 1:≥10 was regarded as reactive and protective. Predictors of vaccination response were analyzed with Poisson regression.

Results

At vaccination, 82% of the vaccinees were taking combination antiretroviral therapy (cART), 83% had suppressed HIV RNA levels (<400 copies/mL), and their median CD4 T-cell count was 536 cells/μL. PRNT was reactive in 46% (95% confidence interval [CI], 38%-53%) before, 95% (95% CI, 91%-98%) within 1 year, 86% (95% CI, 79%-92%) at 5 years, and 75% (95% CI, 62%-85%) at 10 years postvaccination. In those with suppressed plasma HIV RNA at YFV, the proportion with reactive PRNTs remained high: 99% (95% CI, 95%-99.8%) within 1 year, 99% (95% CI, 92%-100%) at 5 years, and 100% (95% CI, 86%-100%) at 10 years.

Conclusions

HIV-infected patients' long-term immune response up to 10 years to YFV is primarily dependent on the control of HIV replication at the time of vaccination. For those on successful cART, immune response up to 10 years is comparable to that of non-HIV-infected adults. We recommend a single YFV booster after 10 years for patients vaccinated on successful cART, whereas those vaccinated with uncontrolled HIV RNA may need an early booster.

Studies with herpes zoster vaccines in immune compromised patients

INTRODUCTION

The active component of the herpes zoster vaccine (ZVL), licensed for people ≥50 years of age, is a live attenuated varicella-zoster virus. ZVL is contraindicated for immune compromised individuals, with limited regard to the degree of immunosuppression. Areas covered: This review evaluates phase I and II and observational studies for ZVL, and published reports of the off-label use of ZVL, for conditions and therapies for which investigators considered the risk-benefit for using ZVL to be favorable. It also discusses exploratory trials of ZVL for additional immune compromising conditions, and summarizes clinical guidelines from many countries and professional societies that are based upon recent investigations. Studies in immune compromised patients of investigational vaccines that do not contain live virus are reviewed. Expert commentary: It is likely that past and ongoing research with ZVL will define immune compromising diseases and/or therapies for which the risk-benefit for using ZVL vaccine is favorable. The main variables to consider in this assessment in immune compromised patients are safety, immunogenicity, protection against herpes zoster, and persistence of protection. Vaccination against herpes zoster prior to suppressing immunity is an important clinical strategy, although efficacy of this approach has not been evaluated in a clinical trial.

Vaccinations for the HIV-Infected Adult: A Review of the Current Recommendations, Part II

Vaccination is a critical component for ensuring the ongoing health HIV-infected adults. Since this group may have reduced immune responses and shorter durations of protection post-vaccination, HIV-specific guidelines have been published. This review article provides a comprehensive discussion of the current guidelines and evidence-based data for vaccinating HIV-infected adults, including data on dosing schedules, immunogenicity studies, and safety. In the current paper, part II of the review, live vaccines, as well as vaccines for travelers and specific occupational groups, will be discussed.

Travel vaccination recommendations and endemic infection risks in solid organ transplantation recipients

BACKGROUND

Solid organ transplant (SOT) recipients are often heavily immunosuppressed and consequently at risk of serious illness from vaccine preventable viral and bacterial infections or with endemic fungal and parasitic infections. We review the literature to provide guidance regarding the timing and appropriateness of vaccination and pathogen avoidance related to the immunological status of SOT recipients.

METHODS

A PUBMED search ([Vaccination OR vaccine] AND/OR ["specific vaccine"] AND/OR [immunology OR immune response OR cytokine OR T lymphocyte] AND transplant was performed. A review of the literature was performed in order to develop recommendations on vaccination for SOT recipients travelling to high-risk destinations.

RESULTS

Whilst immunological failure of vaccination in SOT is primarily the result of impaired B-cell responses, the role of T-cells in vaccine failure and success remains unknown. Vaccination should be initiated at least 4 weeks prior to SOT or more than 6 months post-SOT. Avoidance of live vaccination is generally recommended, although some live vaccines may be considered in the specific situations (e.g. yellow fever). The practicing physician requires a detailed understanding of region-specific endemic pathogen risks.

CONCLUSIONS

We provide a vaccination and endemic pathogen guide for physicians and travel clinics involved in the care of SOT recipients. In addition, recommendations based on timing of anticipated immunological recovery and available evidence regarding vaccine immunogenicity in SOT recipients are provided to help guide pre-travel consultations.

Immunosuppressive medication use and risk of herpes zoster (HZ) in patients with systemic lupus erythematosus (SLE): A nationwide case-control study

BACKGROUND

The association between immunosuppressive medication use and herpes zoster (HZ) in patients with systemic lupus erythematosus (SLE) has not been clearly defined.

OBJECTIVE

We evaluated the risk of HZ in patients with SLE treated with different immunosuppressants.

METHODS

A nationwide population-based case-control study was conducted using the Taiwanese National Health Insurance Research Database. Cases (1555 patients with SLE who developed HZ) and controls (3049 age- and sex-matched patients with SLE but without HZ) were analyzed for use of various immunosuppressive medications in the preceding 3-month period, and dose-response relationships were determined. Logistic regression was performed to estimate the adjusted odds ratio for HZ development.

RESULTS

Medications associated with greater HZ risk in patients with SLE included oral corticosteroids, intravenous methylprednisolone, hydroxychloroquine, oral cyclophosphamide, intravenous cyclophosphamide, azathioprine, methotrexate, and mycophenolate mofetil. Combination immunosuppressive therapy was common in patients with SLE and was associated with greatly increased HZ risk. For oral corticosteroids and hydroxychloroquine, the risk of HZ was strongly dependent on the medication dose.

LIMITATIONS

This study is retrospective in nature.

CONCLUSION

Recent immunosuppressive medication use is associated with increased HZ risk in patients with SLE, particularly those receiving high-dose oral corticosteroids and multiagent immunosuppressive therapy.

Autoimmune disease and vaccination: impact on infectious disease prevention and a look at future applications

Vaccines hold promise both for the prevention of infections and as potential immunologic therapy for patients with autoimmune disease (AD). These patients are at high risk for both common and opportunistic infections, but this risk can be significantly reduced and even obviated with the use of recommended available vaccines. Unfortunately, patients with ADs are not routinely offered or provided indicated vaccinations and have higher rates of complications from vaccine-preventable illnesses than patients without ADs. In addition, vaccine therapy is currently under study for the treatment of autoimmune disorders, with early studies demonstrating immunomodulatory effects that may counter undesired immune activation and alleviate disease activity.

Prevalence and Persistence of Varicella Antibodies in Previously Immunized Children and Youth With Perinatal HIV-1 Infection

BACKGROUND

Two doses of live-attenuated varicella-zoster vaccine are recommended for human immunodeficiency virus 1 (HIV-1)-infected children with CD4% ≥ 15%. We determined the prevalence and persistence of antibody in immunized children with perinatal HIV (PHIV) and their association with number of vaccinations, combination antiretroviral therapy (cART), and HIV status.

METHODS

The Adolescent Master Protocol is an observational study of children with PHIV and perinatally HIV-exposed but uninfected (PHEU) children conducted at 15 US sites. In a cross-sectional analysis, we tested participants' most recent stored sera for varicella antibody using whole-cell and glycoprotein enzyme-linked immunosorbent assay. Seropositivity predictors were identified using multivariable logistic regression models and C statistics.

RESULTS

Samples were available for 432 children with PHIV and 221 PHEU children; 82% of children with PHIV and 97% of PHEU children were seropositive (P < .001). Seropositivity after 1 vaccine dose among children with PHIV and PHEU children was 100% at <3 years (both), 73% and 100% at 3-<7 years (P < .05), and 77% and 97% at ≥ 7 years (P < .01), respectively. Seropositivity among recipients of 2 vaccine doses was >94% at all intervals. Independent predictors of seropositivity among children with PHIV were receipt of 2 vaccine doses, receipt of 1 dose while on ≥ 3 months of cART, compared with none (adjusted odds ratio [aOR]: 14.0 and 2.8, respectively; P < .001 for overall dose effect), and in those vaccinated ≥ 3 years previously, duration of cART (aOR: 1.29 per year increase, P = .02).

CONCLUSIONS

Humoral immune responses to varicella vaccine are best achieved when children with PHIV receive their first dose ≥ 3 months after cART initiation and maintained by completion of the 2-dose series and long-term cART use.

Long-term effect of highly active antiretroviral therapy on immunologic features in children

BACKGROUND

Highly active antiretroviral therapy (HAART) has transformed human immunodeficiency virus infection (HIV) into a chronic condition. The effects of long-term HAART on the immune system activity of early infected children are not fully understood. Hence, the aim of this review is to investigate immune system recovery and residual alteration in HIV-infected children receiving HAART in high-income countries.

METHODS

A systematic review was performed by searches of PubMed and references of the relevant articles. Studies published between January 1, 2000 and April 1, 2014 and conducted in high-income countries reporting data on immunological features in HIV-infected children receiving HAART were included in this review.

RESULTS

Fifty-three articles were included in this review. Present knowledge on B-cell and T-cell function, immunoglobulin production, response to vaccine and innate immune system activity in HIV-infected children receiving HAART is discussed.

CONCLUSION

Starting therapy as soon as diagnosis is ascertained and monitoring vaccine response in children under HAART are the most important tools to safeguard immunological function in HIV-infected children.

Update on opportunistic infections in the era of effective antiretroviral therapy

Despite enormous improvements in effectiveness of treatment for HIV infection, opportunistic infections continue to occur in those who have not yet been diagnosed with HIV and in those who are not receiving antiretroviral therapy. This review focuses on tuberculosis and cryptococcal infections, the most common opportunistic infections (OIs) in patients living with human immunodeficiency virus infection around the world, as well as on new developments in progressive multifocal leukoencephalopathy and pneumocystis pneumonia. In the sections on these conditions, updates on diagnosis, treatment, and complications, as well as information on when to start antiretroviral therapy is provided. The article concludes with a discussion of new data on 2 vaccine-preventable OIs, human papillomavirus and varicella-zoster virus.

Live viral vaccines in immunocompromised patients

ABSTRACT: 

Live-attenuated viral vaccines (LAV) have been used safely for several decades in healthy individuals to protect against diseases with great success. In immunocompromised hosts their use is usually not recommended. We explore the use of currently available LAV, such as live-attenuated influenza, varicella–zoster virus, measles, mumps and rubella, oral polio, rotavirus, yellow fever virus vaccines, especially in patients with cancer, solid organ or hematopoietic stem cell transplant, HIV, and with acquired or congenital immunodeficiencies. Although evidence-based recommendations cannot currently be made, it is possible that LAV will be recommended in specific, well-defined situations in these immunocompromised patients in the future.

Providers' lack of knowledge about herpes zoster in HIV-infected patients is among barriers to herpes zoster vaccination

Identification of perceptions about herpes zoster (HZ) disease, vaccine effectiveness and safety, and vaccine recommendations may impact immunization practices of physicians for HIV-infected patients. A survey was used to quantify knowledge of HZ as well as determine physician immunization perceptions and practices. There were 272/1700 respondents (16%). Correct answers for the incidence of varicella zoster virus (VZV) infection in adults and incidence of HZ in HIV-infected patients were recorded by 14% and 10% of providers, respectively. Providers reported poor knowledge of the incidence of disease recurrence in HIV-infected patients (41% correct), potency of HZ vaccine (47.5% correct) and mechanism of protection against reactivation of VZV (66% correct). Most (88%) agreed that HZ was a serious disease, and 73% believed that the burden of disease made vaccination important. A majority (75%) did not vaccinate HIV patients with HZ vaccine regardless of antiretroviral therapy status. Barriers to administration included safety concerns, concern that vaccine would not prevent HZ, risk of HZ dissemination, reimbursement issues and lack of Infectious Diseases Society of America (IDSA) guidelines. Only 38% of providers agreed that CDC guidelines were clear and 50% believed that clinical trials were needed prior to use of HZ vaccine in HIV-infected patients. Education about HZ is needed among HIV providers. Providers perceived vaccination as important, but data on vaccine safety and clear guidance from the CDC on this issue are lacking.

Acute liver failure due to Varicella zoster virus infection after lung transplantation: a case report

Most adults are Varicella zoster virus (VZV)-positive at the age of 20 years. Some, however, remain antibody-negative and may develop primary chicken pox during adulthood. We report a patient with Williams-Campbell syndrome who underwent double-lung transplantation while being VZV-negative. One year after the successful procedure, he was admitted with fulminant hepatic failure and some cutaneous vesicles in his face. Despite a rapid diagnosis of VZV infection and treatment with acyclovir, his situation deteriorated within 24 hours and while awaiting an urgent liver transplantation, he developed multiple organ failure and died.

Vaccination in HIV-infected individuals

Vaccinations are key to limiting the increased risk of severe infectious diseases in HIV-infected patients for whom the risk–benefit ratio has been re-evaluated. Vaccine safety and immunogenicity depend on both vaccine type and immune deficiency, while vaccine-induced immune activation promotes a transient increase in viral load. Vaccine immunogenicity is reduced and wanes more rapidly, strengthening the need for revaccination. While inactivated vaccines are safe, attenuated vaccines are theoretically contraindicated, but the risk of infectious diseases outweighs the risks of severe adverse events in endemic areas, where the majority of HIV-infected individuals live, thus allowing their use when immune deficiency is moderate. Immune reconstitution with HAART has improved vaccine immune response, highlighting the importance of global access to and early initiation of therapy.

Safety and immunogenicity of the live attenuated varicella vaccine following T replete or T cell-depleted related and unrelated allogeneic hematopoietic cell transplantation (alloHCT)

There are limited studies assessing the live attenuated varicella vaccine following allogeneic hematopoietic cell transplantation (alloHCT). Because of the morbidity of varicella acquired after childhood, we immunized and retrospectively analyzed the safety and immunogenicity of this vaccine in 46 varicella zoster virus (VZV) seronegative patients <20 years old at HCT who achieved a CD4 cell count ≥200/μL, were off immunosuppression, and responded to ≥1 post-HCT vaccines. Two vaccinated patients lacking follow-up titers were excluded from analysis. Stem cells were derived from an HLA-matched sibling (n = 18) or an alternative (HLA mismatched related or unrelated) donor (n = 26). Median time to vaccination was 4 years. Sixty-four percent of patients seroconverted following 1 immunization. There was no significant difference in response between recipients of a matched related or alternative donor graft (P = .2) or between those given a T cell-depleted or T-replete alternative donor graft (P = .27). Three of 44 patients developed a self-limited varicella-like rash within 2.5 weeks of immunization. With a median follow-up of 29.1 (range: 6.9-167.1) months, there were no subsequent cases of varicella-like rashes. No patient developed shingles. This study suggests that this vaccine is safe and immunogenic when given according to preset clinical and immunologic milestones, warranting larger prospective studies in patients ≥24 months following HCT as outlined in current post-HCT vaccine guidelines.