Effectiveness of Recombinant Zoster Vaccine Against Herpes Zoster in a Real-World Setting

BACKGROUND

A 2-dose series of recombinant zoster vaccine (RZV) was 97% effective against herpes zoster (HZ) in a pivotal clinical trial.

OBJECTIVE

To evaluate real-world effectiveness of RZV against HZ.

DESIGN

Prospective cohort study.

SETTING

Four health care systems in the Vaccine Safety Datalink.

PARTICIPANTS

Persons aged 50 years or older.

MEASUREMENTS

The outcome was incident HZ defined by a diagnosis with an antiviral prescription. Cox regression was used to estimate the hazard of HZ in vaccinated persons compared with unvaccinated persons, with adjustment for covariates. Vaccine effectiveness (VE) was calculated as 1 minus the adjusted hazard ratio and was estimated by time since the last RZV dose and by corticosteroid use.

RESULTS

The study included nearly 2.0 million persons who contributed 7.6 million person-years of follow-up. After adjustment, VE of 1 dose was 64% and VE of 2 doses was 76%. After 1 dose only, VE was 70% during the first year, 45% during the second year, 48% during the third year, and 52% after the third year. After 2 doses, VE was 79% during the first year, 75% during the second year, and 73% during the third and fourth years. Vaccine effectiveness was 65% in persons who received corticosteroids before vaccination and 77% in those who did not.

LIMITATION

Herpes zoster could not be identified as accurately in these observational data as in the previous clinical trials.

CONCLUSION

Two doses of RZV were highly effective, although less effective than in the previous clinical trials. Two-dose effectiveness waned very little during the 4 years of follow-up. However, 1-dose effectiveness waned substantially after 1 year, underscoring the importance of the second dose.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

A summary of the Advisory Committee for Immunization Practices (ACIP) use of a benefit-risk assessment framework during the first year of COVID-19 vaccine administration in the United States

To inform Advisory Committee for Immunization Practices (ACIP) COVID-19 vaccine policy decisions, we developed a benefit-risk assessment framework that directly compared the estimated benefits of COVID-19 vaccination to individuals (e.g., prevention of COVID-19-associated hospitalization) with risks associated with COVID-19 vaccines. This assessment framework originated following the identification of thrombosis with thrombocytopenia syndrome (TTS) after Janssen COVID-19 vaccination in April 2021. We adapted the benefit-risk assessment framework for use in subsequent policy decisions, including the adverse events of myocarditis and Guillain-Barre syndrome (GBS) following mRNA and Janssen COVID-19 vaccination respectively, expansion of COVID-19 vaccine approvals or authorizations to new age groups, and use of booster doses. Over the first year of COVID-19 vaccine administration in the United States (December 2020-December 2021), we used the benefit-risk assessment framework to inform seven different ACIP policy decisions. This framework allowed for rapid and direct comparison of the benefits and potential harms of vaccination, which may be helpful in informing other vaccine policy decisions. The assessments were a useful tool for decision-making but required reliable and granular data to stratify analyses and appropriately focus on populations most at risk for a specific adverse event. Additionally, careful decision-making was needed on parameters for data inputs. Sensitivity analyses were used where data were limited or uncertain; adjustments in the methodology were made over time to ensure the assessments remained relevant and applicable to the policy questions under consideration.

Survey of Physician Practices, Attitudes, and Knowledge Regarding Recombinant Zoster Vaccine

BACKGROUND

Herpes zoster vaccination rates remain low despite longstanding national recommendations to vaccinate immunocompetent adults aged ≥ 50 years. The Advisory Committee on Immunization Practice (ACIP) updated its recommendations for recombinant zoster vaccine (RZV) in October 2021 to include immunocompromised adults aged ≥19 years.

OBJECTIVE

To assess practices, attitudes, and knowledge about RZV, barriers to recommending RZV, and likelihood of recommending RZV to patients with various immunocompromising conditions.

DESIGN

Mail and internet-based survey conducted from May through July 2020.

PARTICIPANTS

General internists and family physicians throughout the USA.

MAIN MEASURES

Survey responses.

KEY RESULTS

The response rate was 66% (632/955). Many physicians were already recommending RZV to immunocompromised populations, including adults ≥50 years with HIV (67% of respondents) and on recombinant human immune modulator therapy (56%). Forty-seven percent of respondents both stocked/administered RZV and referred patients elsewhere, frequently a pharmacy, for vaccination; 42% did not stock RZV and only referred patients. The majority agreed pharmacies do not inform them when RZV has been given (64%). Physicians were generally knowledgeable about RZV; however, 25% incorrectly thought experiencing side effects from the first dose of RZV that interfere with normal activities was a reason to not receive the second dose. The top reported barrier to recommending RZV was experience with patients declining RZV due to cost concerns (67%). Most physicians reported they would be likely to recommend RZV to immunocompromised patients.

CONCLUSION

Most primary care physicians welcome updated ACIP RZV recommendations for immunocompromised adults. Knowledge gaps, communication issues, and financial barriers need to be addressed to optimize vaccination delivery.

Six- and 12-month functional outcomes among patients with confirmed acute flaccid myelitis (AFM) with onset in 2018, United States

PURPOSE

Acute flaccid myelitis (AFM), an uncommon but serious neurologic condition, primarily affects children, and can progress quickly to paralysis and respiratory failure. Data on long-term outcomes of patients with AFM are limited. This study reports on functional status through 12 months for AFM patients who became ill in 2018 in the United States.

METHODS

Health departments collected information on outcomes at 6 and 12 months after onset of AFM using a standardized form that asked patients or their parents/guardians about functional status. Analyses were restricted to confirmed cases.

RESULTS

Of the 238 confirmed AFM cases reported to CDC in 2018, 90 (38%) had assessments at 6 months, 82 (34%) at 12 months, and 49 (21%) at both 6 and 12 months. Among the 49 patients with data at both time points, the proportion of patients reporting significant or severe impairment at 6 months ranged from 2% to 59% depending on the outcome. Although proportions decreased by 12 months and ranged from 2% to 51%, most patients had some impairment at 12 months. No deaths were reported.

CONCLUSION

Six- and 12-month outcomes in patients with onset of AFM in 2018 span a wide range of functionality, particularly of upper and lower extremities. Importantly, improvement appears to occur over time in some patients.

Effectiveness of Pfizer-BioNTech COVID-19 vaccine as evidence for policy action: A rapid systematic review and meta-analysis of non-randomized studies

In December 2020, an interim recommendation for the use of Pfizer-BioNTech COVID-19 vaccine in persons aged ≥16 years was made under Food and Drug Administration's Emergency Use Authorization. In preparation for Biologics License Application approval, we conducted a systematic review and meta-analysis to inform the U.S. Centers for Disease Control and Prevention's Advisory Committee for Immunization Practice's (ACIP) decision-making for a standard recommendation. We conducted a rapid systematic review and meta-analysis of Pfizer-BioNTech vaccine effectiveness (VE) against symptomatic COVID-19, hospitalization due to COVID-19, death due to COVID-19, and asymptomatic SARS-CoV-2 infection. We identified studies through August 20, 2021 from an ongoing systematic review conducted by the International Vaccine Access Center and the World Health Organization. We evaluated each study for risk of bias using the Newcastle-Ottawa Scale. Pooled estimates were calculated using meta-analysis. The body of evidence for each outcome was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We identified 80 articles, selected 35 for full-text review, and included 26. The pooled VE of Pfizer-BioNTech COVID-19 vaccine was 92.4% (95% CI: 87.5%-95.3%) against symptomatic COVID-19 with moderate evidence certainty (eight studies), 94.3% (95% CI: 87.9%-97.3%) against hospitalization due to COVID-19 with moderate certainty (eight studies), 96.1% (95% CI: 91.5%-98.2%) against death due to COVID-19 with moderate certainty (four studies), and 89.3% (88.4%-90.1%) against asymptomatic SARS-CoV-2 infection with very low certainty (two studies). The Pfizer-BioNTech COVID-19 vaccine demonstrated high effectiveness in all pre-specified outcomes and extended knowledge of the vaccine's benefits to outcomes and populations not informed by the RCTs. Use of an existing systematic review facilitated a rapid meta-analysis to inform an ACIP policy decision. This approach can be utilized as additional COVID-19 vaccines are considered for standard recommendations by ACIP.

Projected risks and health benefits of vaccination against herpes zoster and related complications in US adults

The Advisory Committee on Immunization Practices (ACIP) recommends recombinant zoster vaccine (RZV) to prevent against herpes zoster (HZ) and related complications in immunocompetent adults ≥50 y and immunocompromised adults ≥19 y. In 2019, a statistical safety signal for Guillain-Barré syndrome (GBS) following RZV was identified using data from the Vaccine Safety Datalink (VSD). Subsequently, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and collaborators undertook additional analyses using Centers for Medicare & Medicaid Services (CMS) Medicare data to further investigate the potential risk of GBS following RZV. Concurrently, epidemiologic data suggested a potentially elevated risk of GBS following HZ in U.S. adults. Using data from these sources and a published simulation model, this study evaluated the health benefits and risks associated with vaccinating immunocompetent adults ≥50 y with RZV compared to no vaccination. In the base case analysis, RZV vaccination averted 43,000-63,000 cases of HZ, including GBS complications, per million vaccinated per 10-y age cohort compared to 3-6 additional cases of GBS projected following RZV per million vaccinated in the same population. This analysis highlights the projected health benefits of RZV vaccination compared to the relatively low potential risk of GBS following RZV.

Recombinant zoster vaccine (RZV) second-dose series completion in adults aged 50-64 years in the United States

In 2018, CDC recommended a highly efficacious adjuvanted recombinant zoster vaccine (RZV) as a 2-dose series for prevention of herpes zoster (HZ) for immunocompetent persons age ≥ 50 years, with the 2nd dose recommended 2-6 months after the 1st dose. We estimated second-dose RZV series completion in the U.S. among 50-64-year-olds using two administrative databases. Second-dose RZV series completion was ∼70% within 6-months and 80% within 12-months of first dose. Among those who received only 1 RZV dose with at least 12 months of follow-up time, 96% had a missed opportunity for a second-dose vaccination, defined as a provider or pharmacy visit, among whom 36% had a visit for influenza or pneumococcal vaccination within 2-12 months of their first-dose of RZV. We found that RZV series completion rates in 50-64-year-olds was high. Availability of RZV at pharmacies has potentially helped increase series completion, but missed opportunities remain.

Measles, Mumps, Rubella Vaccine (PRIORIX): Recommendations of the Advisory Committee on Immunization Practices - United States, 2022

Vaccination is the main means for preventing measles, mumps, and rubella virus infections and their related complications (1,2). Achieving and maintaining high 2-dose measles, mumps, and rubella vaccination coverage in the United States has led to elimination of endemic measles in 2000, rubella and congenital rubella syndrome in 2004, and a sharp decrease in mumps cases. However, measles and rubella remain endemic in many countries, leading to importations of cases and occasional local transmission within the United States (3). Reported U.S. mumps cases declined >99% from the prevaccine period (4); however, mumps is endemic worldwide, and since 2006, the number of mumps cases and mumps outbreaks has increased in the United States, with wider geographic spread since 2016 (4). Given the risk for importation of measles and rubella and the resurgence of mumps, maintaining high measles, mumps, and rubella (MMR) vaccination coverage is important. Since 1978, only one MMR vaccine, M-M-R II (Merck and Co., Inc.), has been available in the United States. On June 6, 2022, the Food and Drug Administration approved a second MMR vaccine, PRIORIX (GlaxoSmithKline Biologicals), for the prevention of measles, mumps, and rubella in persons aged ≥12 months. The three live attenuated viruses contained in PRIORIX are genetically similar or identical to the corresponding components in M-M-R II (Table) (5-7). On June 23, 2022, the Advisory Committee on Immunization Practices (ACIP) unanimously recommended PRIORIX as an option to prevent measles, mumps, and rubella according to the existing recommended schedules and for off-label uses (i.e., indications not included in the package insert)* (1,2). ACIP considered PRIORIX to be safe, immunogenic, and noninferior to M-M-R II. Both PRIORIX and M-M-R II are fully interchangeable for all indications for which MMR vaccination is recommended. This report contains ACIP recommendations specific to PRIORIX and supplements the existing ACIP recommendations for MMR use (1,2).

The Impact of Universal Varicella Vaccination on Herpes Zoster Incidence in the United States: Comparison of Birth Cohorts Preceding and Following Varicella Vaccination Program Launch

When the US varicella vaccination program was introduced in 1995, its impacts on the epidemiology of herpes zoster (HZ) were not precisely known. We used a large claims database to examine HZ incidence in the US during 1998-2019 among persons aged ≥30 years (the prevaccine cohort, born before 1990), and aged 1-29 years (includes the postvaccine cohort, born since 1990). We defined incident HZ as the first instance of an outpatient or emergency department (ED) claim with an HZ diagnostic code. Additionally, we examined the proportion of HZ visits among all ED visits as a complementary method to assess for healthcare-seeking artifacts in the findings. In persons aged ≥30 years (prevaccine cohort), we observed age-specific increases in HZ incidence during the earlier study years, with decelerations in later years, starting in 2007 with oldest age groups. Similar patterns were seen when we examined HZ visits as a proportion of all ED visits. For persons aged 1-29 years, age-specific HZ incidence increased early in the study period for the oldest age groups who were born prevaccine, but later declined in a stepwise pattern once each age group was comprised of persons born in the postvaccine period. Our results, corroborated with previously published studies, do not support prior modeling predictions that the varicella vaccination program would increase HZ incidence among adult cohorts who previously experienced varicella. Our findings also suggest that continued declines in age-specific HZ incidence as varicella-vaccinated cohorts age are likely.

Decline in Severe Varicella Disease During the United States Varicella Vaccination Program: Hospitalizations and Deaths, 1990-2019

To describe the impact of the US varicella vaccination program on severe varicella outcomes, we analyzed varicella hospitalizations using the National Inpatient Sample 1993-2019 and varicella deaths using the National Center for Health Statistics data 1990-2019. Over 25 years of vaccination program (1995-2019), varicella hospitalizations, and deaths declined 94% and 97%, respectively, among persons aged <50 years. Most of the decline (∼90%) occurred during the 1-dose period (through 2006/2007) by attaining and maintaining high vaccination coverage; additional declines occurred during the 2-dose period, especially in the age groups covered by the 2-dose recommendation. The greatest decline for both hospitalizations and deaths (97% and >99%, respectively) was among persons aged <20 years, born during the varicella vaccination program. In the <20 age group, varicella hospitalization has become a rare event, and varicella deaths have been practically eliminated in the United States. A total of >10 500 varicella hospitalizations and 100 varicella deaths are now prevented annually in the United States as a direct result of vaccination and reduction in varicella-zoster virus circulation.

Clinical Manifestations of Varicella: Disease Is Largely Forgotten, but It's Not Gone

After 25 years of varicella vaccination in the United States, classic varicella and its complications have become an uncommon occurrence. The clinical manifestation of varicella among vaccinated persons is usually modified, with fewer skin lesions, mostly maculopapular, and milder presentation. However, the potential for severe manifestations from varicella still exists among both vaccinated and unvaccinated persons, and thus healthcare providers should keep varicella in the differential diagnosis of a maculopapular or vesicular rash. The prompt recognition and diagnosis of varicella is important because when confirmed, clinical and public health measures need to be taken swiftly.

Recombinant Zoster Vaccine Uptake and Risk of Flares Among Older Adults with Immune-Mediated Inflammatory Diseases in the United States

OBJECTIVE

Persons with immune-mediated inflammatory diseases (IMIDs) are at increased risk of herpes zoster (HZ). In 2018, CDC recommended a highly efficacious vaccine, recombinant zoster vaccine (RZV), for prevention of HZ in immunocompetent ≥50 years-olds. We estimated RZV vaccination among adults age ≥50 years with IMIDs during 2018-2019 and examined possible vaccine-related flares following RZV.

METHODS

We identified a cohort of IMID patients using medical claims data from IBM® MarketScan® (age 50-64 years) and Centers for Medicare and Medicaid Services Medicare (age ≥65 years). Presumed flares were defined as hospitalization/emergency department visit for their respective IMIDs, or steroid treatment with a short-acting oral glucocorticoid or parenteral glucocorticoid injection. We conducted a self-controlled case series (SCCS) analysis to examine a temporal association between RZV and flares.

RESULTS

Among enrollees with IMIDs, 14.8% of 55,654 MarketScan and 43.2% of 160,545 Medicare enrollees received ≥1-dose of RZV during 2018-2019. Two-dose series completion was 76.6% in MarketScan and 85.4% in Medicare enrollees. In the SCCS analysis, 10% and 13% developed flares in the control as compared to 9% and 11-12% in the risk window following 1- or 2-doses of RZV among MarketScan and Medicare enrollees, respectively. We found no statistically significant increase in flares following RZV administration for any IMID in either age group following RZV dose-1 or dose-2.

CONCLUSIONS

We did not find an increase in presumed flares following RZV vaccination. Among adults aged ≥50 years with IMIDs, a substantial proportion received RZV compared to general zoster coverage estimates and series-completion was high. This article is protected by copyright. All rights reserved.

Modeling strategies for the allocation of SARS-CoV-2 vaccines in the United States

The Advisory Committee on Immunization Practices (ACIP) recommended phased allocation of SARS-CoV-2 vaccines in December 2020. To support the development of this guidance, we used a mathematical model of SARS-CoV-2 transmission to evaluate the relative impact of three vaccine allocation strategies on infections, hospitalizations, and deaths. All three strategies initially prioritized healthcare personnel (HCP) for vaccination. Strategies of subsequently prioritizing adults aged ≥65 years, or a combination of essential workers and adults aged ≥75 years, prevented the most deaths. Meanwhile, prioritizing adults with high-risk medical conditions immediately after HCP prevented the most infections. All three strategies prevented a similar fraction of hospitalizations. While no model is capable of fully capturing the complex social dynamics which shape epidemics, exercises such as this one can be a useful way for policy makers to formalize their assumptions and explore the key features of a problem before making decisions.

Modeling the Impact of Vaccination Strategies for Nursing Homes in the Context of Increased Severe Acute Respiratory Syndrome Coronavirus 2 Community Transmission and Variants

Using an agent-based model, we examined the impact of community prevalence, the Delta variant, staff vaccination coverage, and booster vaccines for residents on outbreak dynamics in nursing homes. Increased staff coverage and high booster vaccine effectiveness leads to fewer infections, but cumulative incidence is highly dependent on community transmission.

The Advisory Committee on Immunization Practices' Interim Recommendations for Additional Primary and Booster Doses of COVID-19 Vaccines - United States, 2021

Three COVID-19 vaccines are currently approved under a Biologics License Application (BLA) or authorized under an Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) and recommended for primary vaccination by the Advisory Committee on Immunization Practices (ACIP) in the United States: the 2-dose mRNA-based Pfizer-BioNTech/Comirnaty and Moderna COVID-19 vaccines and the single-dose adenovirus vector-based Janssen (Johnson & Johnson) COVID-19 vaccine (1,2) (Box 1). In August 2021, FDA amended the EUAs for the two mRNA COVID-19 vaccines to allow for an additional primary dose in certain immunocompromised recipients of an initial mRNA COVID-19 vaccination series (1). During September-October 2021, FDA amended the EUAs to allow for a COVID-19 vaccine booster dose following a primary mRNA COVID-19 vaccination series in certain recipients aged ≥18 years who are at increased risk for serious complications of COVID-19 or exposure to SARS-CoV-2 (the virus that causes COVID-19), as well as in recipients aged ≥18 years of Janssen COVID-19 vaccine (1) (Table). For the purposes of these recommendations, an additional primary (hereafter additional) dose refers to a dose of vaccine administered to persons who likely did not mount a protective immune response after initial vaccination. A booster dose refers to a dose of vaccine administered to enhance or restore protection by the primary vaccination, which might have waned over time. Health care professionals play a critical role in COVID-19 vaccination efforts, including for primary, additional, and booster vaccination, particularly to protect patients who are at increased risk for severe illness and death.

Modeling the impact of vaccination strategies for nursing homes in the context of increased SARS-CoV-2 community transmission and variants.. [PMID: 34729570 PMCID: PMC8562554 DOI: 10.1101/2021.10.25.21265493]

Nursing homes (NH) were among the first settings to receive COVID-19 vaccines in the United States, but staff vaccination coverage remains low at an average of 64%. Using an agent-based model, we examined the impact of community prevalence, the Delta variant, staff vaccination coverage, and boosters for residents on outbreak dynamics in nursing homes. We found that increased staff primary series coverage and high booster vaccine effectiveness (VE) in residents leads to fewer infections and that the cumulative incidence is highly dependent on community transmission. Despite high VE, high community transmission resulted in continued symptomatic infections in NHs.

Use of Pfizer-BioNTech COVID-19 Vaccine in Persons Aged ≥16 Years: Recommendations of the Advisory Committee on Immunization Practices - United States, September 2021

The Pfizer-BioNTech COVID-19 vaccine (BNT162b2) is a lipid nanoparticle-formulated, nucleoside mRNA vaccine encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. Vaccination with the Pfizer-BioNTech COVID-19 vaccine consists of 2 intramuscular doses (30 μg, 0.3 mL each) administered 3 weeks apart. In December 2020, the vaccine was granted Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) as well as an interim recommendation for use among persons aged ≥16 years by the Advisory Committee on Immunization Practices (ACIP) (1). In May 2021, the EUA and interim ACIP recommendations for Pfizer-BioNTech COVID-19 vaccine were extended to adolescents aged 12-15 years (2). During December 14, 2020-September 1, 2021, approximately 211 million doses of Pfizer-BioNTech COVID-19 vaccine were administered in the United States.* On August 23, 2021, FDA approved a Biologics License Application for use of the Pfizer-BioNTech COVID-19 vaccine, Comirnaty (Pfizer, Inc.), in persons aged ≥16 years (3). The ACIP COVID-19 Vaccines Work Group's conclusions regarding the evidence for the Pfizer-BioNTech COVID-19 vaccine were presented to ACIP at a public meeting on August 30, 2021. To guide its deliberations regarding the Pfizer-BioNTech COVID-19 vaccine, ACIP used the Evidence to Recommendation (EtR) Framework,† and incorporated a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.§ In addition to initial clinical trial data, ACIP considered new information gathered in the 8 months since issuance of the interim recommendation for Pfizer-BioNTech COVID-19 vaccine, including additional follow-up time in the clinical trial, real-world vaccine effectiveness studies, and postauthorization vaccine safety monitoring. The additional information increased certainty that benefits from prevention of asymptomatic infection, COVID-19, and associated hospitalization and death outweighs vaccine-associated risks. On August 30, 2021, ACIP issued a recommendation¶ for use of the Pfizer-BioNTech COVID-19 vaccine in persons aged ≥16 years for the prevention of COVID-19.

Herpes Zoster Risk in Immunocompromised Adults in the United States: A Systematic Review

BACKGROUND

The primary reported risk factors for herpes zoster (HZ) include increasing age and immunodeficiency, yet estimates of HZ risk by immunocompromising condition have not been well characterized. We undertook a systematic literature review to estimate the HZ risk in immunocompromised patients.

METHODS

We systematically reviewed studies that examined the risk of HZ and associated complications in adult patients with hematopoietic cell transplants (HCT), cancer, human immunodeficiency virus (HIV), and solid organ transplant (SOT). We identified studies in PubMed, Embase, Medline, Cochrane, Scopus, and clinicaltrials.gov that presented original data from the United States and were published after 1992. We assessed the risk of bias with Cochrane or Grading of Recommendations Assessment, Development, and Evaluation methods.

RESULTS

We identified and screened 3765 records and synthesized 34 studies with low or moderate risks of bias. Most studies that were included (32/34) reported at least 1 estimate of the HZ cumulative incidence (range, 0-41%). There were 12 studies that reported HZ incidences that varied widely within and between immunocompromised populations. Incidence estimates ranged from 9 to 92 HZ cases/1000 patient-years and were highest in HCT, followed by hematologic malignancies, SOT, and solid tumor malignancies, and were lowest in people living with HIV. Among 17 HCT studies, the absence of or use of antiviral prophylaxis at <1 year post-transplant was associated with a higher HZ incidence.

CONCLUSIONS

HZ was common among all immunocompromised populations studied, exceeding the expected HZ incidence among immunocompetent adults aged ≥60 years. Better evidence of the incidence of HZ complications and their severity in immunocompromised populations is needed to inform economic and HZ vaccine policies.

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.

The Advisory Committee on Immunization Practices' Ethical Principles for Allocating Initial Supplies of COVID-19 Vaccine - United States, 2020

To reduce the spread of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) and its associated impacts on health and society, COVID-19 vaccines are essential. The U.S. government is working to produce and deliver safe and effective COVID-19 vaccines for the entire U.S. population. The Advisory Committee on Immunization Practices (ACIP)* has broadly outlined its approach for developing recommendations for the use of each COVID-19 vaccine authorized or approved by the Food and Drug Administration (FDA) for Emergency Use Authorization or licensure (1). ACIP's recommendation process includes an explicit and transparent evidence-based method for assessing a vaccine's safety and efficacy as well as consideration of other factors, including implementation (2). Because the initial supply of vaccine will likely be limited, ACIP will also recommend which groups should receive the earliest allocations of vaccine. The ACIP COVID-19 Vaccines Work Group and consultants with expertise in ethics and health equity considered external expert committee reports and published literature and deliberated the ethical issues associated with COVID-19 vaccine allocation decisions. The purpose of this report is to describe the four ethical principles that will assist ACIP in formulating recommendations for the allocation of COVID-19 vaccine while supply is limited, in addition to scientific data and implementation feasibility: 1) maximize benefits and minimize harms; 2) promote justice; 3) mitigate health inequities; and 4) promote transparency. These principles can also aid state, tribal, local, and territorial public health authorities as they develop vaccine implementation strategies within their own communities based on ACIP recommendations.

A Cost-Effectiveness Analysis of Vaccination for Prevention of Herpes Zoster and Related Complications: Input for National Recommendations

BACKGROUND

The U.S. Advisory Committee on Immunization Practices recently developed recommendations for use of a new recombinant zoster vaccine (RZV).

OBJECTIVE

To evaluate the cost-effectiveness of vaccination with RZV compared with zoster vaccine live (ZVL) and no vaccination, the cost-effectiveness of vaccination with RZV for persons who have previously received ZVL, and the cost-effectiveness of preferential vaccination with RZV over ZVL.

DESIGN

Simulation (state-transition) model using U.S. epidemiologic, clinical, and cost data.

DATA SOURCES

Published data.

TARGET POPULATION

Hypothetical cohort of immunocompetent U.S. adults aged 50 years or older.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal and health care sector.

INTERVENTION

Vaccination with RZV (recommended 2-dose regimen), vaccination with ZVL, and no vaccination.

OUTCOME MEASURES

The primary outcome measure was the incremental cost-effectiveness ratio (ICER).

RESULTS OF BASE-CASE ANALYSIS

For vaccination with RZV compared with no vaccination, ICERs ranged by age from $10 000 to $47 000 per quality-adjusted life-year (QALY), using a societal perspective and assuming 100% completion of the 2-dose RZV regimen. For persons aged 60 years or older, ICERs were less than $60 000 per QALY. Vaccination with ZVL was dominated by vaccination with RZV for all age groups 60 years or older.

RESULTS OF SENSITIVITY ANALYSIS

Results were most sensitive to changes in vaccine effectiveness, duration of protection, herpes zoster incidence, and probability of postherpetic neuralgia. Vaccination with RZV after previous administration of ZVL yielded an ICER of less than $60 000 per QALY for persons aged 60 years or older. In probabilistic sensitivity analyses, RZV remained the preferred strategy in at least 95% of simulations, including those with 50% completion of the second dose.

LIMITATION

Few data were available on risk for serious adverse events, adherence to the recommended 2-dose regimen, and probability of recurrent zoster.

CONCLUSION

Vaccination with RZV yields cost-effectiveness ratios lower than those for many recommended adult vaccines, including ZVL. Results are robust over a wide range of plausible values.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

Cost-effectiveness of adult vaccinations: A systematic review

BACKGROUND

Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent years, which may contribute to low awareness of the value of adult vaccinations and to their under-utilization. We assessed research literature since 1980 to summarize economic evidence for adult vaccinations included on the adult immunization schedule.

METHODS

We searched PubMed, EMBASE, EconLit, and Cochrane Library from 1980 to 2016 and identified economic evaluation or cost-effectiveness analysis for vaccinations targeting persons aged ≥18 years in the U.S. or Canada. After excluding records based on title and abstract reviews, the remaining publications had a full-text review from two independent reviewers, who extracted economic values that compared vaccination to "no vaccination" scenarios.

RESULTS

The systematic searches yielded 1688 publications. After removing duplicates, off-topic publications, and publications without a "no vaccination" comparison, 78 publications were included in the final analysis (influenza = 25, pneumococcal = 18, human papillomavirus = 9, herpes zoster = 7, tetanus-diphtheria-pertussis = 9, hepatitis B = 9, and multiple vaccines = 1). Among outcomes assessing age-based vaccinations, the percent indicating cost-savings was 56% for influenza, 31% for pneumococcal, and 23% for tetanus-diphtheria-pertussis vaccinations. Among age-based vaccination outcomes reporting $/QALY, the percent of outcomes indicating a cost per QALY of ≤$100,000 was 100% for influenza, 100% for pneumococcal, 69% for human papillomavirus, 71% for herpes zoster, and 50% for tetanus-diphtheria-pertussis vaccinations.

CONCLUSIONS

The majority of published studies report favorable cost-effectiveness profiles for adult vaccinations, which supports efforts to improve the implementation of adult vaccination recommendations.

2500. Incidence of Herpes Zoster in the Pre- and Post-Vaccine Era: Do Trends Differ Between Blacks And Whites?

Background

Herpes zoster (HZ) incidence in blacks is 25%–65% lower than in whites in the United States. Since 2007 and the widespread introduction of Zostavax (ZVL), studies report plateauing or decreasing HZ incidence in the United States among persons ≥60 years. We examined HZ incidence and ZVL coverage trends by race among Medicare beneficiaries, in the pre- and post-vaccine era.

Methods

We used administrative health claims from a 5% sample of Medicare beneficiaries ≥65 years. We defined incident cases as HZ in the first diagnostic position, with no HZ code in the previous year, among beneficiaries enrolled in Part A and B, from 1992 to 2015. We calculated incidence of first HZ episode by dividing the number of cases by the total number of person-years (p-y). A case was a censoring event. We used Poisson regression to compare HZ incidence by race before and after 2007. We calculated vaccine coverage by dividing the total number of persons with ZVL in Medicare Part D by the number of eligible enrollees.

Results

We identified 266,745 first HZ episodes. Prior to 2007, HZ incidence increased among both blacks and whites. Although incidence was double in whites vs. blacks (10.3 vs. 5.0 cases/1000 p-y), the rate of increase was similar (P = 0.75). From introduction of ZVL to 2015, HZ incidence decreased 1.8%/year in whites and did not change significantly in blacks (P < 0.001) (figure). By 2015, ZVL uptake in Medicare among blacks was less than half that among whites (7.3% vs. 19.9%).

Conclusion

Incidence of HZ increased at a similar rate for black and white Medicare beneficiaries in the pre-vaccine era. In the post-vaccine era, incidence has decreased among whites and plateaued among blacks. Though the reasons for racial difference and temporal changes in HZ incidence remain unknown, ecologic association suggests higher vaccination rates may contribute to steeper HZ declines among whites in the post vaccine era.

Disclosures

All authors: No reported disclosures.

2284. Ten-Year Effectiveness of Live Virus Herpes Zoster Vaccine

Background

Although recombinant zoster vaccine (RZV) is recommended preferentially in adults aged ≥50 years in the United States, zoster vaccine live (ZVL) remains a recommended vaccine in immunocompetent adults aged ≥60 years and is currently being used in many countries around the world. Assessing the long-term effectiveness of both vaccines is critical for determining vaccine policy, including the optimal age to begin vaccination and the need for and timing of revaccination. We evaluated the long-term effectiveness of ZVL in adults ≥ 60 years old in the United States.

Methods

We conducted a retrospective cohort study at Kaiser Permanente Southern California (KPSC). The exposed cohort included KPSC members ≥60 years vaccinated with ZVL during 1/1/2007- 12/31/2014. Three unvaccinated members were matched to each vaccinated member on age, sex, and length of membership. Individuals were followed to 6/30/2017. Electronic health records were used to identify incident herpes zoster (HZ). The effectiveness of ZVL and its 95% confidence interval (CI) at each year following vaccination was estimated.

Results

The number of HZ cases was 7,783 in 923,176 person-years (8.4 per 1,000; 95% CI, 8.2–8.6 per 1,000) among vaccinated persons and 26,813 in 1,964,974 person-years (13.6 per 1,000; 95% CI, 13.5–13.8 per 1,000) among unvaccinated persons. The HZ incidence rate ratio, comparing the vaccinated to the unvaccinated, was 0.62 (95% CI, 0.60–0.63). The effectiveness by year after vaccination decreased each year of follow-up from 65.8% (95% CI, 63.2%-68.2%) in the first year, 49.3% (95% CI, 45.7%-52.6%) in the second, 32.0% (95% CI, 24.1%-39.1%) to 36.8% (95% CI, 32.3%-40.9%) in the third - sixth year, and 22.0% (95% CI, -2.5%- 40.6%) to 23.6% (95% CI, 13.4%-32.7%) in the seventh - 10^th year. A similar pattern was seen between those 60–69 years and ≥70 years of age.

Conclusion

The effectiveness of ZVL declined from 66% in the first year to 22% in the 10^th year after vaccination. This 10-year effectiveness study of ZVL provides insights into a revaccination strategy and need for a more effective and durable vaccine. Studies of long-term effectiveness of RZV are also warranted.

Disclosures

All authors: No reported disclosures.

Performance of Zoster Vaccine Live (Zostavax): A Systematic Review of 12 years of Experimental and Observational Evidence

Background

One in three people in the U.S. will develop herpes zoster during their life. Zoster Vaccine Live (ZVL or Zostavax™), has been licensed in the U.S. since 2006 to prevent herpes zoster. ZVL protection has been shown to wane with time and estimates of effect can be imprecise. We performed a systematic review of the duration of efficacy and effectiveness of ZVL against herpes zoster (HZ).

Methods

We systematically searched PubMed, Embase, Cochrane, and clinicaltrials.gov for vaccine efficacy or effectiveness (VE) studies of ZVL. Two authors independently screened each title and abstract, and potential VE studies were reviewed in-depth. Eligibility criteria included original data on ZVL prevention of HZ in a general population of immunocompetent recipients ≤ 60 years old. Selected articles were abstracted, independently reviewed, and discrepancies adjudicated. We attempted to locate relevant unpublished work and contacted authors for additional data, where necessary. Measures of association were illustrated on a forest plot and converted to VE (1-hazard ratio or risk ratio or odds ratio).

Results

We screened 1302 articles; 17 underwent full text review and 8 met inclusion criteria and were abstracted for this review. Selected studies included 1 phase III randomized controlled trial, 2 quasi experimental and 5 observational studies. One experimental and 5 observational studies estimated VE during the period from vaccination up to 4 years following vaccination; estimates across studies ranged from 33%-55%. Two quasi experimental and 3 observational studies estimated VE for ≥ 4 years following vaccination; estimates ranged from 19%-40%; the median estimate was 24% (Figure). Pooled VE was not calculated due to heterogeneity in length of follow up, age distribution of study subjects, as well as adjustment for factors such as underlying medical conditions.

Conclusion

Most experimental and observational studies estimate VE just above 50% during the 3 years following receipt of ZVL. Beyond 3 years, ZVL protection wanes, with most studies estimating a VE of ≤24% after 4 years. Information on overall efficacy and duration of protection from ZVL will guide policy decisions regarding its use.

Disclosures

E. Belongia, Novavax: Investigator, Research support

Prolonged Excretion of Poliovirus among Individuals with Primary Immunodeficiency Disorder: An Analysis of the World Health Organization Registry

Individuals with primary immunodeficiency disorder may excrete poliovirus for extended periods and will constitute the only remaining reservoir of virus after eradication and withdrawal of oral poliovirus vaccine. Here, we analyzed the epidemiology of prolonged and chronic immunodeficiency-related vaccine-derived poliovirus cases in a registry maintained by the World Health Organization, to identify risk factors and determine the length of excretion. Between 1962 and 2016, there were 101 cases, with 94/101 (93%) prolonged excretors and 7/101 (7%) chronic excretors. We documented an increase in incidence in recent decades, with a shift toward middle-income countries, and a predominance of poliovirus type 2 in 73/101 (72%) cases. The median length of excretion was 1.3 years (95% confidence interval: 1.0, 1.4) and 90% of individuals stopped excreting after 3.7 years. Common variable immunodeficiency syndrome and residence in high-income countries were risk factors for long-term excretion. The changing epidemiology of cases, manifested by the greater incidence in recent decades and a shift to from high- to middle-income countries, highlights the expanding risk of poliovirus transmission after oral poliovirus vaccine cessation. To better quantify and reduce this risk, more sensitive surveillance and effective antiviral therapies are needed.

Invasive group A Streptococcus infections associated with liposuction surgery at outpatient facilities not subject to state or federal regulation

IMPORTANCE

Liposuction is one of the most common cosmetic surgery procedures in the United States. Tumescent liposuction, in which crystalloid fluids, lidocaine, and epinephrine are infused subcutaneously before cannula-assisted aspiration of fat, can be performed without intravenous or general anesthesia, often at outpatient facilities. However, some of these facilities are not subject to state or federal regulation and may not adhere to appropriate infection control practices.

OBJECTIVE

To describe an outbreak of severe group A Streptococcus (GAS) infections among persons undergoing tumescent liposuction at 2 outpatient cosmetic surgery facilities not subject to state or federal regulation.

DESIGN

Outbreak investigation (including cohort analysis of at-risk patients), interviews using a standardized questionnaire, medical record review, facility assessment, and laboratory analysis of GAS isolates.

SETTING AND PARTICIPANTS

Patients undergoing liposuction at 2 outpatient facilities, one in Maryland and the other in Pennsylvania, between July 1 and September 14, 2012.

MAIN OUTCOMES AND MEASURES

Confirmed invasive GAS infections (isolation of GAS from a normally sterile site or wound of a patient with necrotizing fasciitis or streptococcal toxic shock syndrome), suspected GAS infections (inflamed surgical site and either purulent discharge or fever and chills in a patient with no alternative diagnosis), postsurgical symptoms and patient-reported experiences related to his or her procedure, and emm types, T-antigen types, and antimicrobial susceptibility of GAS isolates.

RESULTS

We identified 4 confirmed cases and 9 suspected cases, including 1 death (overall attack rate, 20% [13 of 66]). One instance of likely secondary GAS transmission to a household member occurred. All confirmed case patients had necrotizing fasciitis and had undergone surgical debridement. Procedures linked to illness were performed by a single surgical team that traveled between the 2 locations; 2 team members (1 of whom reported recent cellulitis) were colonized with a GAS strain that was indistinguishable by laboratory analysis of the isolates from the case patients. Facility assessments and patient reports indicated substandard infection control, including errors in equipment sterilization and infection prevention training.

CONCLUSIONS AND RELEVANCE

This outbreak of severe GAS infections was likely caused by transmission from colonized health care workers to patients during liposuction procedures. Additional oversight of outpatient cosmetic surgery facilities is needed to assure that they maintain appropriate infection control practices and other patient protections.

Nutritional status of under-five children living in an informal urban settlement in Nairobi, Kenya

Malnutrition in sub-Saharan Africa contributes to high rates of childhood morbidity and mortality. However, little information on the nutritional status of children is available from informal settlements. During the period of post-election violence in Kenya during December 2007-March 2008, food shortages were widespread within informal settlements in Nairobi. To investigate whether food insecurity due to post-election violence resulted in high prevalence of acute and chronic malnutrition in children, a nutritional survey was undertaken among children aged 6-59 months within two villages in Kibera, where the Kenya Medical Research Institute/Centers for Disease Control and Prevention conducts population-based surveillance for infectious disease syndromes. During 25 March-4 April 2008, a structured questionnaire was administered to caregivers of 1,310 children identified through surveillance system databases to obtain information on household demographics, food availability, and child-feeding practices. Anthropometric measurements were recorded on all participating children. Indices were reported in z-scores and compared with the World Health Organization (WHO) 2005 reference population to determine the nutritional status of children. Data were analyzed using the Anthro software of WHO and the SAS. Stunting was found in 47.0% of the children; 11.8% were underweight, and 2.6% were wasted. Severe stunting was found in 23.4% of the children; severe underweight in 3.1%, and severe wasting in 0.6%. Children aged 36-47 months had the highest prevalence (58.0%) of stunting while the highest prevalence (4.1%) of wasting was in children aged 6-11 months. Boys were more stunted than girls (p < 0.01), and older children were significantly (p < 0.0001) stunted compared to younger children. In the third year of life, girls were more likely than boys to be wasted (p < 0.01). The high prevalence of chronic malnutrition suggests that stunting is a sustained problem within this urban informal settlement, not specifically resulting from the relatively brief political crisis. The predominance of stunting in older children indicates failure in growth and development during the first two years of life. Food programmes in Kenya have traditionally focused on rural areas and refugee camps. The findings of the study suggest that tackling childhood stunting is a high priority, and there should be fostered efforts to ensure that malnutrition-prevention strategies include the urban poor.

Assessing secondary attack rates among household contacts at the beginning of the influenza A (H1N1) pandemic in Ontario, Canada, April-June 2009: a prospective, observational study

BACKGROUND

Understanding transmission dynamics of the pandemic influenza A (H1N1) virus in various exposure settings and determining whether transmissibility differed from seasonal influenza viruses was a priority for decision making on mitigation strategies at the beginning of the pandemic. The objective of this study was to estimate household secondary attack rates for pandemic influenza in a susceptible population where control measures had yet to be implemented.

METHODS

All Ontario local health units were invited to participate; seven health units volunteered. For all laboratory-confirmed cases reported between April 24 and June 18, 2009, participating health units performed contact tracing to detect secondary cases among household contacts. In total, 87 cases and 266 household contacts were included in this study. Secondary cases were defined as any household member with new onset of acute respiratory illness (fever or two or more respiratory symptoms) or influenza-like illness (fever plus one additional respiratory symptom). Attack rates were estimated using both case definitions.

RESULTS

Secondary attack rates were estimated at 10.3% (95% CI 6.8-14.7) for secondary cases with influenza-like illness and 20.2% (95% CI 15.4-25.6) for secondary cases with acute respiratory illness. For both case definitions, attack rates were significantly higher in children under 16 years than adults (25.4% and 42.4% compared to 7.6% and 17.2%). The median time between symptom onset in the primary case and the secondary case was estimated at 3.0 days.

CONCLUSIONS

Secondary attack rates for pandemic influenza A (H1N1) were comparable to seasonal influenza estimates suggesting similarities in transmission. High secondary attack rates in children provide additional support for increased susceptibility to infection.