Meningococcal serogroup B vaccination series initiation in the United States: A real-world claims data analysis

In the United States (US), meningococcal serogroup B (MenB) vaccination has been recommended for 16-23-year-olds (preferably 16-18 years) based on shared clinical decision-making since 2015. MenB vaccine coverage (≥1 dose) by age 17 years has been reported, but initiation at older ages and by insurance type is unknown. In this retrospective cohort study, MarketScan claims data were analyzed to assess MenB vaccine series initiation (i.e. receipt of a first dose) during 2017-2020 among US commercially insured and Medicaid-covered individuals aged 16-18 and 19-23 years. Kaplan-Meier curves were generated to estimate series initiation at various times from index (latest of 1/1/2017 or 16^th/19^th birthday, depending on the cohort). Multivariable analyses were conducted to identify factors associated with series initiation. Among 1,450,354 Commercial and 1,140,977 Medicaid 16-18-year-olds, MenB vaccine series initiation rates within 3 years of each person's first eligibility were estimated to be 33% and 20%, respectively; among 1,857,628 Commercial and 747,483 Medicaid 19-23-year-olds, 3% and 1%, respectively. Factors identified to be significantly associated with increased likelihood of initiating a MenB vaccine series included co-administration of meningococcal serogroups ACWY (MenACWY) vaccine, younger age, female sex, nonwhite race (Medicaid only), New England or Middle Atlantic location (Commercial only), urban residence, and previous influenza vaccination. MenB vaccine series initiation among the studied US adolescents and young adults was low. There is a need for continued efforts to better understand barriers to the uptake of vaccines that are recommended based on shared clinical decision-making.

Estimating the cost of university-based outbreaks of serogroup B meningococcal disease with different pre-matriculation vaccination policies in the United States

Objective: We developed an Excel-based cost calculator to assess the economic burden of university-based Neisseria meningitidis serogroup B (MenB) outbreaks. Participants: Hypothetical university with 6,354 students. Methods: Total societal costs of outbreak were estimated for three MenB pre-matriculation immunization policies-vaccination required, vaccination recommended, and no vaccine policy-under three different cost assumptions (low/mid-range/high cost). Results: Mid-range cost estimates of an outbreak under "no policy" were $2.60 and $2.70 million (of which 35% were incurred by the university) if targeting all undergraduates for mass vaccination with a two-/three-dose vaccine, respectively. The "required" and "recommended" policies lowered the burden to $2.17-$2.18 million and $2.34-$2.39 million, respectively. For a larger university with 40,000 students, costs were almost $9 million for a two-dose vaccine with "no policy" in place. Conclusions: The economic burden of a university MenB outbreak is substantial, but could be mitigated by a pre-matriculation MenB vaccination requirement or recommendation.

A Real-world Claims Data Analysis of Meningococcal Serogroup B Vaccine Series Completion and Potential Missed Opportunities in the United States

BACKGROUND

In the United States, meningococcal serogroup B (MenB) vaccination is recommended for 16-23-year-olds based on shared clinical decision-making. We estimated series completion among individuals initiating MenB vaccination for the 2 available vaccines: MenB 4-component (MenB-4C, doses at 0 and ≥1 month) and MenB factor H binding protein (MenB-FHbp, doses at 0 and 6 months).

METHODS

This retrospective health insurance claims data analysis included 16-23-year-olds who initiated MenB vaccination (index date) during January 2017 to November 2018 (MarketScan Commercial Claims and Encounters Database) or January 2017 to September 2018 (MarketScan Multi-State Medicaid Database) and had continuous enrollment for ≥6 months before and ≥15 months after index. The main outcome was MenB vaccine series completion within 15 months. Among noncompleters, preventive care/well-child and vaccine administrative office visits were identified as potential missed opportunities for series completion. Robust Poisson regression models identified independent predictors of series completion.

RESULTS

In the Commercial (n = 156,080) and Medicaid (n = 57,082) populations, series completion was 56.7% and 44.7%, respectively, and was higher among those who initiated MenB-4C versus MenB-FHbp (61.1% versus 49.8% and 47.8% versus 33.9%, respectively; both P < 0.001). Among noncompleters, 40.2% and 34.7% of the Commercial and Medicaid populations, respectively, had ≥1 missed opportunity for series completion. Receipt of MenB-4C and younger age were independently associated with a higher probability of series completion.

CONCLUSIONS

Series completion rates were suboptimal but were higher among those who initiated MenB-4C. To maximize the benefits of MenB vaccination, interventions to improve completion and reduce missed opportunities should be implemented.

Meningococcal Vaccination Rates Among People With a New Diagnosis of HIV Infection in the US

IMPORTANCE

In the United States, individuals with HIV infection have been recommended to receive a 2-dose series of the meningococcal A, C, W, Y (MenACWY) vaccine since 2016 owing to their increased risk of meningococcal disease.

OBJECTIVE

To examine uptake and time to receipt of the MenACWY vaccine among people with a new diagnosis of HIV.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used health insurance data from the US Optum Research Database from January 1, 2016, through March 31, 2018, to retrospectively identify 1208 individuals aged 2 years or older with 1 or more inpatient claim or 2 or more outpatient claims evidencing a new diagnosis of HIV infection and with continuous insurance enrollment for 12 or more months before and 6 or more months after diagnosis. Follow-up was 6 to 33 months. Statistical analysis was conducted from March 7, 2019, to January 5, 2022.

EXPOSURE

Receipt of the MenACWY vaccine.

MAIN OUTCOMES AND MEASURES

The coprimary outcomes were uptake and time to receipt of 1 or more doses of the MenACWY vaccine after a new HIV diagnosis. Secondary outcomes included uptake and time to receipt of 2 or more doses of the MenACWY vaccine. Vaccination uptake and receipt were estimated by Kaplan-Meier analysis; factors associated with receipt of 1 or more doses of the MenACWY vaccine were identified with multivariable Cox proportional hazards regression analysis.

RESULTS

Of 1208 individuals eligible for vaccination (1024 male patients [84.8%]; mean [SD] age, 38.8 [12.5] years; 35 [2.9%] Asian; 273 [22.6%] Black; 204 [16.9%] Hispanic; 442 [36.6%] White), 16.3% were estimated to have received a first dose of the MenACWY vaccine in the 2 years after a new HIV diagnosis. Among individuals who received a first dose, at 1 year or more of enrollment after the first dose, 66.2% were estimated to have received a second dose within 1 year of the first dose. Factors statistically significantly associated with uptake of the MenACWY vaccine included receipt of a pneumococcal vaccine (hazard ratio [HR], 23.03; 95% CI, 13.93-38.09), attendance at a well-care visit (HR, 3.67; 95% CI, 1.11-12.12), West or Midwest geographic region (West: HR, 2.24; 95% CI, 1.44-3.47; Midwest: HR, 1.78; 95% CI, 1.16-2.71), and male sex (HR, 2.72; 95% CI, 1.18-6.26), whereas age of 56 years or older was significantly associated with reduced uptake of the MenACWY vaccine (HR, 0.42; 95% CI, 0.18-0.97).

CONCLUSIONS AND RELEVANCE

This cohort study suggests that MenACWY vaccine uptake among people with a new diagnosis of HIV was low, highlighting the need to educate patients and clinicians about the recommendations for conditions such as HIV infection that increase the risk of meningococcal disease among high-risk populations.

National and State-Level Composite Completion of Recommended Vaccines Among Adolescents in the United States, 2015-2018

BACKGROUND

Routine adolescent vaccination recommendations in the United States include tetanus, diphtheria, and acellular pertussis, quadrivalent meningococcal conjugate vaccine, and human papillomavirus vaccines. Although coverage for these individual vaccines is known, limited data are available on composite completion for all three vaccines.

METHODS

This cross-sectional analysis of pooled 2015-2018 National Immunization Survey-Teen data used logistic regression to estimate model-adjusted composite vaccination completion nationally and by state among United States adolescents aged 17 years. National Immunization Survey-Teen data were combined with state-level data to estimate a multilevel model identifying factors associated with composite vaccination completion.

RESULTS

The pooled model-adjusted composite vaccination completion was 30.6% (95% confidence interval [CI], 30.13%-31.04%) nationally, varying from 11.3% in Idaho (6.91%-17.95%) to 56.4% (49.81%-62.82%) in Rhode Island. Individual-level factors with the greatest impact on composite completion were having a provider's recommendation for human papillomavirus vaccination (odds ratio, 3.24; 95% CI, 2.76-3.80) and a check-up visit at age 16-17 years (odds ratio, 2.35; 95% CI, 1.80-3.07), with other individual-level factors associated with completion including being Medicaid insured, female, Hispanic, or non-Hispanic black. State-level quadrivalent meningococcal conjugate vaccination mandates were also associated with an increased likelihood of composite vaccination completion (odds ratio, 1.64; 95% CI, 1.16-2.33).

CONCLUSIONS

Fewer than one-third of 17-year-old individuals have completed all three recommended vaccines, with rates varying by state. Although this study identified implementable strategies to improve composite completion, additional research is needed to further understand factors associated with adolescent vaccination completion.

Low Meningococcal Vaccination Rates Among Patients With Newly Diagnosed Complement Component Deficiencies in the United States

Meningococcal vaccination is recommended for patients with complement component deficiencies (CDs) in the United States. In this retrospective database study, only 4.6% and 2.2% of patients received MenACWY and MenB vaccination, respectively, within 3 years of CD diagnosis. Thus, meningococcal vaccination rates among patients with CDs need to be improved.

Meningococcal B vaccination coverage among older adolescents in the United States

BACKGROUND

Serogroup B meningococcal (MenB) vaccination recommendations for adolescents in the United States (US) include routine vaccination for all individuals at increased risk and vaccination for individuals not at increased risk aged 16-23 years (preferred age 16-18 years) based on shared clinical decision-making. The two licensed MenB vaccines require administration of ≥2 doses.

METHODS

This cross-sectional study analyzed 2017-2018 National Immunization Survey-Teen (NIS-Teen) data to evaluate ≥1 dose and ≥2 dose MenB vaccination coverage among adolescents aged 17 years. Multivariable logistic regression was used to further evaluate determinants of MenB vaccination.

RESULTS

Nationally, MenB vaccination coverage among 17-year-olds increased from 14.5% in 2017 to 17.2% in 2018 for ≥1 dose and from 6.3% to 8.4% for ≥2 doses. MenB vaccination coverage (2017-2018) was the lowest in the South (≥1 dose: 14.6%; ≥2 doses: 6.3%) and highest in the Northeast region (18.3% and 9.3%), with variation observed by census division. Adolescents were more likely to have received ≥1 dose of MenB vaccine if they had any Medicaid insurance (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.32-2.39) or had received human papillomavirus (OR, 1.94; 95% CI, 1.41-2.67) or meningococcal A, C, W, and Y (OR, 4.03; 95% CI, 2.92-5.56) vaccinations.

CONCLUSIONS

MenB first-dose coverage in the US is low, and even lower for a second dose, with regional variation. Being up to date with other routinely administered vaccines increased the likelihood of receiving MenB vaccination.

179. Individual and State-level Factors Associated with Receipt of Multiple Recommended Adolescent Vaccines in the United States

Background

The Advisory Committee on Immunization Practices (ACIP) routinely recommends several adolescent vaccines, including human papillomavirus (HPV); quadrivalent meningococcal conjugate (MenACWY); and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines. Limited data are available on the percentage of adolescents receiving this complement of ACIP-recommended vaccines and factors that may increase likelihood of completion.

Methods

This study used 2015–18 pooled National Immunization Survey-Teen (NIS-Teen) data to estimate national and state-level completion rates by age 17 of a two-dose MenACWY series, two- or three- dose HPV series (depending on age at first vaccination), and a Tdap vaccine, using multivariable logistic regression modeling to adjust for individual characteristics. NIS-Teen data were then combined with public state-level data to construct a multilevel model evaluating effects of both individual- and state-level factors on completion.

Results

After adjusting for individual-level factors, the national completion rate for these ACIP-recommended vaccines by age 17 was 30.6% (95% confidence interval [CI]: 30.1–31.0%). However, rates for individual states varied substantially, from 11.3% in Idaho (CI: 6.9–18.0%) to 56.4% in Rhode Island (CI: 49.8–62.8%) (Figure 1).

In the multilevel model, individual characteristics associated with increased likelihood of receiving the recommended vaccines by age 17 included female gender, black or Hispanic race, Medicaid coverage (vs. private/other), last provider visit at age 16 or 17, generally having ≥1 provider visit in last year, and receiving a provider recommendation for HPV vaccination. Residing in a state with a MenACWY vaccination mandate for elementary and secondary schools was the only state-level variable that significantly increased the likelihood of completion (odds ratio: 1.6; CI: 1.2–2.3) (Figure 2).

Figure 1: Model-Adjusted Completion Rates of ACIP-Recommended HPV, MenACWY, and Tdap Vaccines by Age 17 Years in the United States, 2015–18. ACIP, Advisory Committee on Immunization Practices; HPV, human papillomavirus; MenACWY, quadrivalent meningococcal conjugate; Tdap, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis. Note: Vaccination completion is based on completion of the HPV series (i.e., receipt of 2 doses for individuals aged 9–14 years at first vaccination or receipt of 3 doses for individuals aged 15 years or older at first vaccination), completion of the MenACWY series (i.e., receipt of 2 doses), and receipt of a Tdap vaccine. Note: Model-adjusted composite vaccination completion is adjusted for sex, race/ethnicity, mother’s educational attainment, health insurance status, continuity of health insurance coverage since age 11, whether the individual was 16 or 17 years old at their last checkup, number of physician or other healthcare professional visits in past 12 months, whether a doctor or other healthcare professional ever recommended that the individual receive HPV vaccination, and state. The model-adjusted estimate is generated by taking the average of the predicted probability of vaccination for each individual as if they were all from the same state (while retaining all other characteristics).

Figure 2: Individual-Level and State-Level Characteristics Associated with an Individual’s Completion of ACIP-Recommended HPV, MenACWY, and Tdap Vaccines by Age 17 Years in the United States, 2015–18. ACIP, Advisory Committee on Immunization Practices; CI, confidence interval; HCP, healthcare professional; HPV, human papillomavirus; MenACWY, quadrivalent meningococcal conjugate; ref, referent category; Tdap, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis. Note: Bold characters and darker circles indicate significant results. Note: Vaccination completion is based on completion of the HPV series (i.e., receipt of 2 doses for individuals aged 9–14 years at first vaccination or receipt of 3 doses for individuals aged 15 years or older at first vaccination), completion of the MenACWY series (i.e., receipt of 2 doses), and receipt of a Tdap vaccine.

Conclusion

Recommended adolescent vaccine completion rates are suboptimal and highly variable across states. Provider recommendations, visits at 16–17 years of age, and state mandates for MenACWY are implementable strategies associated with completion of recommended adolescent vaccines.

Funding

GlaxoSmithKline Biologicals SA (study identifier: HO-19-19991)

Disclosures

Elizabeth M. La, PhD, RTI Health Solutions (Employee) Diana Garbinsky, MS, GSK (Other Financial or Material Support, The study was conducted by RTI Health Solutions, which received consultancy fees from GSK. I am a salaried employee at RTI Health Solutions and received no direct compensation from GSK for the conduct of this study..) Shannon Hunter, MS, GSK (Other Financial or Material Support, Ms. Hunter is an employee of RTI Health Solutions, who received consultancy fees from GSK for conduct of the study. Ms. Hunter received no direct compensation from the Sponsor.) Sara Poston, PharmD, The GlaxoSmithKline group of companies (Employee, Shareholder) Patricia Novy, PhD, GSK (Employee, Shareholder) Parinaz Ghaswalla, PhD, ORCID: 0000-0002-2883-5590, GlaxoSmithKline (Employee, Shareholder)

7. Two-Dose 4CMenB Vaccination in Adolescents Elicits a Bactericidal Activity against 15 Outbreak-Representative Meningococcal Strains

Background

Meningococcal outbreaks have often been associated with N. meningitidis serogroup B (MenB) in high-income countries. We examined whether antibodies elicited by the 4-component MenB vaccine (4CMenB) in adolescents could induce complement-mediated bacterial killing of a panel of 14 genetically diverse MenB strains representative of outbreaks that occurred from 2001 to 2016 (11 from the US, 2 from the UK, and 1 from France). One N. meningitidis serogroup W (MenW) hyperendemic strain (UK, 2011) was also included in the analysis.

Methods

In a previous multicenter study (NCT02212457), adolescents aged 10-18y received 2 4CMenB doses 2 months apart. We tested individual sera collected from a subgroup of 20 US participants at pre-vaccination and 1 month post-second dose in a serum bactericidal assay with human complement (hSBA) against the meningococcal strain panel. Similarly, sera collected from 23 Chilean adolescents aged 11-17y (NCT00661713) were tested in a hSBA against a subset of 4 strains (3 from the US, 1 from the UK).

Results

At baseline, the percentage of US subjects with seroprotective titers (hSBA ≥ 1:4) ranged from 5% to 35%. One month after 4CMenB series completion, 65% to 100% had seroprotective titers (hSBA ≥ 1:4) against 11 out of the 14 MenB tested strains. The seroprotection rate was 45%, 25%, and 15% against the 3 remaining MenB strains. Against MenW, the percentage of adolescents with hSBA titers ≥ 1:4 was 15% at baseline and 95% one month after series completion. No significant changes in the percentage of subjects were observed when analysing hSBA titers ≥ 1:8. Moreover, the subset analysis indicated similar results for US and Chilean subjects for 3 out of 4 strains: the percentage of US vs Chilean subjects with hSBA titers ≥ 1:4 was 100% vs 100%; 80% vs 74%; 45% vs 52%. For the 4th strain, 65% of US subjects vs 91% of Chilean subjects showed a hSBA ≥ 1:4.

Conclusion

4CMenB elicited bactericidal antibodies against a panel of 14 outbreak-representative MenB strains and 1 MenW hyperendemic strain in US adolescents. No major differences were detected in the bactericidal activity of Chilean subjects vaccinated with 4CMenB when tested against a subset of 4 MenB outbreak strains, suggesting that the immune response to 4CMenB is comparable in adolescents from different geographic areas.

Disclosures

Alessia Biolchi, n/a, GSK (Employee) Sara Tomei, n/a, GSK (Employee) Laura Santini, n/a, GSK (Employee) Rita La Gaetana, n/a, GSK Vaccines (Employee, Shareholder) Elena Mori, n/a, GSK (Employee) Patricia Novy, PhD, GSK (Employee, Shareholder) Rino Rappuoli, PhD, GSK (Employee) Rafik Bekkat-Berkani, M.D, GSK (Employee, Shareholder) Marzia Monica Giuliani, n/a, GSK (Employee, Shareholder) Mariagrazia Pizza, Biological Sciences, PhD, GSK Vaccines (Employee)

Meningococcal vaccination in patients with newly diagnosed asplenia in the United States

BACKGROUND

Patients with asplenia are recommended to receive meningococcal ACWY (MenACWY) and B (MenB) vaccines in the United States (US).

OBJECTIVES

To examine uptake and time to receipt of meningococcal vaccines in newly diagnosed asplenia patients, and identify factors associated with vaccination.

METHODS

For this retrospective database analysis, patients were identified from 1/1/2010 (MenACWY) or 1/1/2015 (MenB) through 3/31/2018 from an administrative claims database including commercially insured US patients with ≥1 inpatient or ≥2 outpatient claims with evidence of a new asplenia diagnosis (sickle cell disease was excluded); continuous enrollment for ≥12 months before and ≥6 months after the index date; and age ≥2 (MenACWY) or ≥10 (MenB) years. Co-primary outcomes were uptake and time to receipt of ≥1 dose, separately for MenACWY and MenB, by Kaplan-Meier analysis. Cox proportional hazards regression models were used to identify characteristics associated with vaccination.

RESULTS

Among 2,273 and 741 patients eligible for the MenACWY and MenB analyses, respectively, 28.1% and 9.7% received MenACWY and MenB in the first 3 years after a new asplenia diagnosis. Patients were more likely to receive meningococcal vaccines if they had received pneumococcal vaccines (MenACWY: hazard ratio [HR] 26.02; 95% confidence interval [CI] 21.01-32.22; MenB: HR 3.89; 95% CI 2.07-7.29) or attended ≥1 well-care visit (MenACWY: HR 6.63; 95% CI 4.84-9.09; MenB: HR 11.17; 95% CI 3.02-41.26).

CONCLUSIONS

Meningococcal vaccination rates among newly diagnosed asplenia patients were low, highlighting the need to educate providers about the recommendations for high-risk conditions and ensure healthcare access for vulnerable patients.

2726. Meningococcal Vaccination Among Patients Newly Diagnosed at High-Risk for Meningococcal Disease in the United States

Background

Quadrivalent conjugate and polysaccharide meningococcal vaccines (MenACWY) have been recommended in the United States for patients at high-risk due to functional or anatomic asplenia, complement component deficiency (CD) and human immunodeficiency virus (HIV) infection. Serogroup B vaccines (MenB) are recommended for patients ≥10 years of age with asplenia or CD. Little is currently known about meningococcal vaccine uptake and time to vaccination among patients with incident high-risk diagnoses.

Methods

Patients newly diagnosed (1 inpatient or ≥2 outpatient medical claims with evidence of the condition ≥30 days apart) with functional or anatomic asplenia (excluding sickle cell disease), CD or HIV infection were identified in the Optum Research Database. Continuous enrollment for ≥12 months before and ≥6 months after the diagnosis date (index date) was required. Patients with evidence of pre-existing conditions were excluded. MenACWY uptake was assessed among patients ≥2 years of age at index date from January 1, 2010 for asplenia and CD, and January 1, 2016 for HIV infection, through March 31, 2018; and MenB uptake among patients ≥10 years of age at index date from January 1, 2015 through March 31, 2018. Current Procedural Terminology and National Drug Codes on medical claims were used to capture vaccinations. For each condition, Kaplan–Meier analysis was used to estimate uptake and time to receipt of ≥1 dose of each vaccine for up to 5 years post-index date; vaccinations within 90 days before the index date were also included in calculations.

Results

Among asplenia patients, the percentage with receipt of ≥1 dose of MenACWY at 1, 2.5, and 5 years post-index date was 6.6%, 9.4%, and 13.3%, respectively; for CD patients the corresponding percentages were 2.2%, 4.8%, and 8.3%; and for HIV patients at 1 and 2.5 years post-index date the percentages were 10.8% and 19.8% (Figure 1). Receipt of ≥1 dose of MenB at 1 and 2.5 years post-index date was 1.7% and 3.1%, respectively, for asplenia patients and 1.1% and 2.5%, respectively, for CD patients (Figure 2).

Conclusion

Uptake of meningococcal vaccines in patients newly diagnosed with high-risk conditions is very low and the time to vaccination is long, leaving patients vulnerable to invasive meningococcal disease for extended periods of time.

Disclosures

All authors: No reported disclosures.

Determinants of Meningococcal ACWY vaccination in adolescents in the US: completion and compliance with the CDC recommendations

Since 2011, the Advisory Committee on Immunization Practices (ACIP) guidelines for routine MenACWY vaccination in the US include a primary dose before age 16 y, preferably at ages 11-12 y, with a booster dose at age 16 y. Data on rates and drivers of meningococcal vaccination completion (receipt of both doses) and compliance with recommendations (receipt of primary dose at ages 11-12 y followed by booster at 16 y) down to state-level are limited.This study evaluated rates and determinants of MenACWY vaccination completion and compliance in adolescents aged 17 y based on data from the annual National Immunization Survey-Teen between 2011 and 2016. Individual- and state-level determinants of completion and compliance were assessed using uni-level and multi-level multivariable regression models. Average national rates were 23.2% and 12.1% for completion and compliance, respectively, with large inter-state variation observed (completion: 8.7-39.7%; compliance: 3.1-26.2%). Beyond the state of residence, factors significantly associated with a higher likelihood of both completion and compliance included being male, up-to-date on other routine vaccines, having private or hospital-based vaccine providers (vs. public) and having >1 child in the household. Factors specifically associated with completion included having >1 annual health-care visit and presence of a booster-dose vaccine mandate, while a history of asthma and high-risk health conditions had a positive association with compliance. State-level determinants of completion and compliance included pediatricians-to-children ratio and the proportion of Immunization Information System use among adolescents, respectively. Outcomes of this study may help guide clinical, policy and educational interventions to further increase MenACWY completion rates and reduce disparities in vaccination.

Meningococcal Vaccination Among Adolescents in the United States: A Tale of Two Age Platforms

PURPOSE

Despite recommended routine vaccination with meningococcal conjugate vaccine (MenACWY) at ages 11-12 years with a booster at age 16 years, national estimates indicate MenACWY uptake is lower in older adolescents than younger adolescents. This study aimed to identify factors associated with MenACWY uptake among adolescents.

METHODS

Commercial Claims and Encounters (CCAE) and Medicaid MarketScan Databases from 2011 to 2016 were retrospectively analyzed (2017) to determine receipt of ≥1 dose of MenACWY during early (10.5 through 13 years) and late (15.5 through 18 years) adolescence. Multivariable logistic regression and nonlinear decomposition analyses were used to identify factors associated with MenACWY vaccination, potential missed opportunities, and differences between age groups.

RESULTS

A larger proportion of younger adolescents than older adolescents received MenACWY: CCAE, 71.7% versus 48.9% (p < .001); Medicaid, 59.3% versus 31.8% (p < .001), respectively. In multivariable models (CCAE), older adolescents were less likely than younger ones to receive MenACWY (adjusted odds ratios [95% confidence intervals]: .68 [.67, .69]) and more likely to have a potential missed opportunity (1.27 [1.25, 1.28]). Decomposition results showed lower MenACWY uptake in older adolescents is largely attributed to fewer non-MenACWY vaccines received, fewer preventive care visits, and interaction with nonpediatric healthcare providers.

DISCUSSION

Missed opportunities and infrequent preventive care encounters contribute to lack of vaccination in younger and older adolescents. However, the disparity in uptake between the two age groups was largely attributable to differences in healthcare utilization, suggesting a need for unique strategies to increase uptake among older adolescents, such as solidifying a vaccination platform for ages 16-18 years through encouragement of annual preventive care visits.

Optimizing the timing of 4CMenB vaccination in adolescents and young adults based on immune persistence and booster response data

INTRODUCTION

Meningococcal disease has an incidence peak spread over several years during adolescence and young adulthood in the United States. Meningococcal serogroup B (MenB) vaccines have been introduced relatively recently and may help protect individuals in these age groups. Currently there is insufficient long-term experience to determine the duration of disease protection after any MenB vaccine. Understanding antibody persistence after primary vaccination and responses to booster can help inform MenB vaccination strategies and optimize disease prevention. Areas covered: Four studies in adolescents/young adults vaccinated with meningococcal B vaccine 4CMenB were reviewed with the aim to compare findings across studies and draw key learnings. The studies varied by geographic location, population characteristics, and timing of antibody measurement relative to primary vaccination. Expert opinion: Antibody persistence data for 4CMenB are substantial, extending 7.5 years post-primary vaccination. Vaccination at age 16-18 years may help protect adolescents throughout their highest age-based risk period. Similar robust responses to a single booster dose were observed 4 and 7.5 years after primary vaccination. In outbreak settings it is beneficial to have received prior vaccination; residual circulating antibodies may provide protection, and a single dose induces booster responses within 7 days, which is quicker than administration of a 2-dose series to vaccine-naïve individuals.

2459. Meningococcal ACWY (MenACWY) Vaccination of Adolescents in the United States: How Compliant Are We With the Advisory Committee on Immunization Practices (ACIP) Recommendations?

Background

Since 2011, ACIP guidelines for routine meningococcal ACWY vaccination (MenACWY) include a primary dose before age 16 (preferably at ages 11–12) and a booster dose (preferred age 16). Data on rates and drivers of meningococcal vaccination completion and compliance with ACIP recommendations down to state level are limited.

Methods

The 2011–2016 US National Immunization Survey-Teen data among adolescents aged 17 were used (GSK study identifier: HO-17-18202). National and state prevalence were estimated for MenACWY completion (receipt of primary dose at ages 11–15 and booster dose at age 16 or older) and compliance (receipt of primary dose at ages 11–12 and booster dose at age 16). Determinants such as state of residence, demographics, clinical/provider characteristics, vaccine mandates were assessed using multivariable logistic regression. Survey sampling weights were used to obtain population-based estimates.

Results

The estimated national average prevalence based on 2011–2016 data were 23.2% for MenACWY vaccine completion and 12.1% for compliance in US adolescents. Across states, prevalence varied from 8.7–39.7% for completion and 3.1–26.2% for compliance (Figure 1). Beyond state of residence, factors significantly associated with higher likelihood of both completion and compliance included being male, being up-to-date on other routine vaccines, having private or hospital-based vaccine providers (vs. public), and having >1 child in the household. Factors associated only with completion included having an 11- to 12-year-old well-child examination (OR [95% CI]: 1.5 [1.0–2.2]), >1 annual healthcare visit (2–5 vs. none) (1.4 [1.1–1.8]), and an existing state booster dose vaccine mandate (2.0 [1.5–2.8]) while factors associated with only compliance included history of asthma (1.3 [1.1–1.6]) and high-risk health conditions (1.4 [1.0–2.0]).

Conclusion

Adolescent completion and compliance rates for MenACWY vaccination in the United States are suboptimal, with significant variability across states. Determinants of completion and compliance with ACIP recommendations identified in this study may help guide clinical, policy, and educational interventions to promote healthcare access/utilization among adolescents in order to increase vaccine uptake.

Disclosures

W. Cheng, Analysis Group, Inc.: Employee, Research grant. R. Chang, Analysis Group, Inc.: Employee, Research grant. P. Novy, GSK: Employee, Salary. C. O’Connor, Analysis Group, Inc.: Employee, Research grant. M. S. Duh, Analysis Group, Inc.: Employee, Research grant. C. Hogea, GSK: Employee, Salary.

NKT cells are essential for innate immune control of vaccinia viral infection in vivo (108.3)

The role of natural killer T (NKT) cells during the innate immune response to pathogen remains incompletely defined. We previously showed that early control of vaccinia virus is critically dependent on the activation of natural killer (NK) cells. Here we show that in CD1d-deficient hosts, early control of vaccinia virus is compromised. This defect in viral clearance corresponds to an insufficient NK cell response, as NK cells from CD1d-deficient hosts have reduced production of the effector molecules IFN-γ and Granzyme B. Furthermore, NK cells from infected CD1d-deficient mice fail to lyse target cells when used in a chromium release assay. These data suggest a role for NKT cells in NK cell activation. In vitro, NK cell activation in response to vaccinia is dependent on both dendritic cells (DC) and NKT cells. We observe that NKT cells produce high levels of IFN-γ in response to vaccinia virus, and the production of IL-12 by DC is dependent on NKT cell presence. Direct contact between NKT cells and DC is required to fully license them to effectively activate NK cells, a phenomenon that may be attributed to upregulation of activating NK ligands RAE-1 and MULT-1 on DC surfaces. Overall, our data show that NKT cells are required for the activation of NK cells during vaccinia infection and suggest that NKT cells license DC to optimally activate NK cells. These data indicate that NKT cells are key players in the early generation of an innate immune response to viral infection.

Intrinsic IL-21 signaling is critical for CD8 T cell survival and memory formation in response to vaccinia viral infection

CD4 T cell help plays an important role in promoting CD8 T cell immunity to pathogens. In models of infection with vaccinia virus (VV) and Listeria monocytogenes, CD4 T cell help is critical for the survival of activated CD8 T cells during both the primary and memory recall responses. Still unclear, however, is how CD4 T cell help promotes CD8 T cell survival. In this study, we first showed that CD4 T cell help for the CD8 T cell response to VV infection was mediated by IL-21, a cytokine produced predominantly by activated CD4 T cells, and that direct action of IL-21 on CD8 T cells was critical for the VV-specific CD8 T cell response in vivo. We next demonstrated that this intrinsic IL-21 signaling was essential for the survival of activated CD8 T cells and the generation of long-lived memory cells. We further revealed that IL-21 promoted CD8 T cell survival in a mechanism dependent on activation of the STAT1 and STAT3 pathways and subsequent upregulation of the prosurvival molecules Bcl-2 and Bcl-x(L). These results identify a critical role for intrinsic IL-21 signaling in CD8 T cell responses to an acute viral infection in vivo and may help design effective vaccine strategies.

Intrinsic IL-21 signaling is critical for CD8 T cell memory formation in response to Vaccinia viral infection (50.32)

The role of CD4 T cell help in primary and memory CD8 T cell responses to infectious pathogens remains incompletely defined. We showed previously that CD4 help provided during both the primary and secondary responses to vaccinia virus (VV) is required for the survival of activated CD8 T cells. Still unclear however, is the mechanism of CD4 help during the response to VV infection. Here we demonstrate that CD4 help is neither dependent on dendritic cell (DC) priming nor is contact dependent, indicating that CD4 help may be dependent on a soluble mediator. We determined that in vitro CD4 help for CD8 survival is dependent on IL-21, a cytokine produced predominantly by activated CD4 T cells. Furthermore, IL-21 signaling is required for the survival of activated CD8 T cells in vivo and CD8 T cells deficient in IL-21 signaling failed to develop a memory pool. In addition, we observed that IL-21 signaling in CD8 T cells can activate the STAT1 and STAT3 signaling pathways, both of which have been correlated to CD8 survival. Our study shows that direct IL-21 signaling is required for the formation of memory CD8 cells in response to VV and indicates that CD4-help may be mediated by IL-21 during VV infection. This suggests that differential IL-21 requirements during different pathogen infections may dictate the necessity of CD4 help in the primary CD8 response.

CD4 T cells are required for CD8 T cell survival during both primary and memory recall responses

The role of CD4 T cell help in primary and secondary CD8 T cell responses to infectious pathogens remains incompletely defined. The primary CD8 T response to infections was initially thought to be largely independent of CD4 T cells, but it is not clear why some primary, pathogen-specific CD8 T cell responses are CD4 T cell dependent. Furthermore, although the generation of functional memory CD8 T cells is CD4 T cell help dependent, it remains controversial when the "help" is needed. In this study, we demonstrated that CD4 T cell help was not needed for the activation and effector differentiation of CD8 T cells during the primary response to vaccinia virus infection. However, the activated CD8 T cells showed poor survival without CD4 T cell help, leading to a reduction in clonal expansion and a diminished, but stable CD8 memory pool. In addition, we observed that CD4 T cell help provided during both the primary and secondary responses was required for the survival of memory CD8 T cells during recall expansion. Our study indicates that CD4 T cells play a crucial role in multiple stages of CD8 T cell response to vaccinia virus infection and may help to design effective vaccine strategies.

A comparison of recovering alcoholic and non-alcoholic smokers

Whether smokers with a positive past history (PH) of alcohol dependence need more intensive or different treatment than smokers with no such history (NH) is unclear. We surveyed 31 PH smokers and 31 age and sex-matched NH smokers to examine differences in motivations for and barriers to stopping smoking. The final regression model found that PH and NH smokers did not differ in social support, social pressure, readiness to quit or physical consequences of smoking; however, PH smokers were more dependent on nicotine and had more internal (affective) barriers to cessation than NH smokers. Although our results require replication due to our small sample size, they do suggest that PH smokers would especially benefit from medications for nicotine dependence and medications or psychosocial treatments for depression.