Impact of Meningococcal ACWY Vaccination Program during 2017-18 Epidemic, Western Australia, Australia.

The rising incidence of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup W in Western Australia, Australia, presents challenges for prevention. We assessed the effects of a quadrivalent meningococcal vaccination program using 2012-2020 IMD notification data. Notification rates peaked at 1.8/100,000 population in 2017; rates among Aboriginal and Torres Strait Islander populations were 7 times higher than for other populations. Serogroup W disease exhibited atypical manifestations and increased severity. Of 216 cases, 20 IMD-related deaths occurred; most (19/20) were in unvaccinated persons. After the 2017-2018 targeted vaccination program, notification rates decreased from 1.6/100,000 population in 2018 to 0.9/100,000 population in 2019 and continued to decline in 2020. Vaccine effectiveness (in the 1-4 years age group) using the screening method was 93.6% (95% CI 50.1%-99.2%) in 2018 and 92.5% (95% CI 28.2%-99.2%) in 2019. Strategic planning and prompt implementation of targeted vaccination programs effectively reduce IMD.

Nurses' preferences regarding MenACWY conjugate vaccines attributes: a discrete choice experiment in Spain.

OBJECTIVES: Immunisation against preventable diseases as meningitis is crucial from a public health perspective to face challenges posed by these infections. Nurses hold a great responsibility for these programs, which highlights the importance of understanding their preferences and needs to improve the success of campaigns. This study aimed to investigate nurses' preferences regarding Meningococcus A, C, W, and Y (MenACWY) conjugate vaccines commercialised in Spain. STUDY DESIGN: A national-level discrete choice experiment (DCE) was conducted. METHODS: A literature review and a focus group informed the DCE design. Six attributes were included: pharmaceutical form, coadministration evidence, shelf-life, package contents, single-doses per package, and package volume. Conditional logit models quantified preferences and relative importance (RI). RESULTS: Thirty experienced primary care nurses participated in this study. Evidence of coadministration with other vaccines was the most important attribute (RI = 43.78%), followed by package size (RI = 22.17%), pharmaceutical form (RI = 19.07%), and package content (RI = 11.80%). There was a preference for evidence of coadministration with routine vaccines (odds ratio [OR] = 2.579, 95% confidence interval [95%CI] = 2.210-3.002), smaller volumes (OR = 1.494, 95%CI = 1.264-1.767), liquid formulations (OR = 1.283, 95%CI = 1.108-1.486) and package contents including only vial/s (OR = 1.283, 95%CI = 1.108-1.486). No statistical evidence was found for the remaining attributes. CONCLUSIONS: Evidence of coadministration with routine vaccines, easy-to-store packages, and fully liquid formulations were drivers of nurses' preferences regarding MenACWY conjugate vaccines. These findings provide valuable insights for decision-makers to optimize current campaigns.

Adolescent and parental decision-making for the MenACWY vaccination: influential predictors and parental-adolescent differences among households in the Netherlands.

BACKGROUND: Between 2015 and 2018 The Netherlands experienced increases of invasive meningococcal disease (IMD) serogroup W (MenW). Therefore in 2018 the MenACWY vaccination was introduced in the National Immunisation Programme (NIP) and a catch-up campaign was initiated targeting adolescents. This study aimed to gain insight into what factors played a role in the decision-making process regarding the MenACWY vaccination. The focus was on the differences in the decision-making of parents and adolescents in order to assess what factors influence the decisions made. METHODS: An online questionnaire was offered to adolescents and one of their parents. We used random forest analyses to determine which factors best predict the outcome of the MenACWY vaccination decision. We carried out ROC (receiver-operator characteristics) analyses to confirm the predictive value of the variables. RESULTS: Among parents several factors stand out, centring on the process of the decision, their attitude about the MenACWY vaccination, trust in the vaccination, and ideas of important people around them. Among adolescents the three stand-out predictors are the ideas of important people around them, the process of the decision and trust in the vaccination. Parents have prominent influence in the decision-making, while the adolescent's influence in the household decision-making is more limited. Adolescents tend to be less engaged and spend less time thinking about the decision compared to parents. Opinions of parents and adolescents from the same households concerning the factors that are influential do not differ a lot in the final decision-making. CONCLUSIONS: Information about MenACWY vaccination might be mainly addressed to the parents of the adolescents and whereby the dialogue about MenACWY vaccination between parents and adolescents will be stimulated. With regard to the predictor trust in vaccination, raising the frequency of use of certain sources, especially those deemed very reliable among households such as conversations with a GP or the provider of the vaccination (GGD/JGZ), might prove a useful strategy to solidify vaccination uptake numbers.

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.

Psychosocial and organizational barriers and facilitators of meningococcal vaccination (MenACWY) acceptance among adolescents and parents during the Covid-19 pandemic: a cross-sectional survey.

BACKGROUND: This study aimed to identify differences and similarities among adolescents and parents in various psychosocial factors influencing meningococcal ACWY (MenACWY) vaccination acceptance. Besides, the impact of the Covid-19 pandemic was assessed as well as resulting organizational adjustments. METHODS: We conducted a cross-sectional survey among adolescents that attended the appointment for the MenACWY vaccination in South Limburg between May and June 2020, and their parents. Independent t-tests and χ2 test were performed to explore differences in psychosocial and organisational factors between adolescents and parents. RESULTS: In total, 592 adolescents (20%) and 1197 parents (38%) filled out the questionnaire. Adolescents scored lower on anticipated negative affect towards MenACWY vaccination refusal [t (985.688) = - 9.32; ρ < 0.001], moral norm towards MenACWY vaccination acceptance [t (942.079) = - 10.38; ρ < 0.001] and knowledge about the MenACWY vaccination and meningococcal disease [t (1059.710) = - 11.24; ρ < 0.001]. Both adolescents and parents reported a social norm favouring accepting childhood vaccinations, but adolescent scored higher [t (1122.846) = 23.10; ρ < 0.001]. The Covid-19 pandemic did barely influence the decision to accept the MenACWY vaccination. Only 6% of the participants indicated that Covid-19 influenced their decision. In addition, the individual vaccination appointment was rated very positive. Most adolescents (71.5%) and parents (80.6%) prefer future vaccinations to be offered individually rather than having mass vaccinations sessions. CONCLUSIONS: This study provides an indication of which psychosocial and organisational factors should be addressed in future MenACWY vaccination campaigns. Individual vaccination appointments for adolescents should be considered, taking the costs and logistical barriers into account.

MenQuadfi (MenACWY-TT): A New Vaccine for Meningococcal Serogroups ACWY.

OBJECTIVE: This article reviews data encompassing the pharmacology, efficacy, and safety of MenACWY-TT (MenQuadfi), a conjugate vaccine to prevent meningococcal disease from serogroups A, C, W, Y. DATA SOURCES: A literature review was conducted in PubMed, MEDLINE, and ClinicalTrials.gov from inception up to July 2021, using the search terms MenQuadfi, meningococcal ACWY vaccine, MCV4, and menacwy. Articles from reference lists were included to identify potential relevant literature. STUDY SELECTION AND DATA EXTRACTION: Data were limited to randomized phase II and III clinical studies published in the English language, evaluating the efficacy and safety of MenACWY-TT. Animal studies and studies not utilizing MenACWY-TT were excluded. DATA SYNTHESIS: One phase II and 4 phase III randomized clinical studies, enrolling approximately 7700 participants, aged 2 years to 97 years old found that MenACWY-TT was noninferior when compared to established MenACWY vaccines, as measured by surrogate immunogenicity end points. In studies evaluating primary dose vaccination, conducted in those aged 2 to 97 years of age, the difference in seroresponse rates, reported by the lower bound of the 95% CI, was (A) 1.1% to 14.8%, (C) 21% to 42.2%, (Y) 7.7% to 24.6%, and (W) 8.9% to 22.5%. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Despite the low incidence of meningococcal disease in the United States, meningococcal disease causes significant morbidity and mortality if not prevented. CONCLUSION: MenACWY-TT is noninferior to currently approved quadrivalent meningococcal vaccines and shows similar immunogenicity and safety as both an initial vaccine for prevention as well as a booster dose.

Dynamics in public perceptions and media coverage during an ongoing outbreak of meningococcal W disease in the Netherlands.

BACKGROUND: From 2015 to 2018, the Netherlands faced an outbreak of invasive meningococcal disease (IMD) caused by serogroup W. To counter the rise in infections, the government introduced a catch-up menACWY vaccination campaign for teenagers in 2018 and 2019. The outbreak situation induced substantial media attention and a run on menACWY vaccines outside the vaccination campaign. This study aimed to gain insights into the dynamics of public perceptions of and responses to the outbreak and the menACWY vaccination, and into the media coverage about the outbreak. METHODS: Three repeated surveys (N = 1110) between 2017 and 2019 were sent to parents of teenagers invited for a menACWY catch-up vaccination, other parents, and individuals with no under-age children. These surveys assessed IMD risk perceptions, attitudes towards the menACWY vaccination, trust in involved institutions, and willingness to vaccinate with the menACWY vaccine. Changes in the public perceptions and responses were studied with linear multilevel regression analyses. In addition, 103 national newspaper articles from the period 2017-2019 were thematically coded with themes about IMD and the menACWY vaccination. RESULTS: The survey results showed clear increases in perceived IMD severity, positive attitude towards the menACWY vaccination, and willingness to vaccinate over time. Perceived IMD vulnerability remained low across all three waves, and trust in involved institutions increased slightly. Differences between the survey groups were limited. The newspaper articles discussed the rise in infections extensively, the disease symptoms, and the possible fatal outcome of IMD. In addition, while many articles discussed the menACWY vaccine shortage, few discussed the safety or effectiveness of the vaccine. CONCLUSION: The real-time insights into the interrelated dynamics of public perceptions, responses, and media coverage provide an integrated portrait of the social developments during this outbreak. The focus on IMD severity and the absence of doubt in the public discussion about vaccine safety may have played an important role in the societal response to this outbreak and the recommended vaccine.

Outcomes from the Use of Targeted Interventions to Increase Meningococcal Vaccination Rates in a Pediatric Clinic.

BACKGROUND: Meningococcal disease is a life-threatening illness that can cause sequelae such as neurological impairment, hearing loss, seizures, limb amputations, and scarring. Adolescents and young adults are at highest risk for contracting this disease which comes with a case-fatality ratio of 10-15%. Common serogroups in the United States are B, C, W, and Y, which are covered by two separate vaccines administered in a two-dose series. While MenACWY is routinely administered, the booster dose is often missed. Only 21.8% of teens reported receiving the MenB vaccine. While it is not currently part of routine care, recent outbreaks have been caused by serogroup B, prompting the need for increased vaccination rates. METHODS: MenACWY and MenB vaccination rates and demographic information were collected for 16-19-year-old patients in a pediatric clinic. Interventions including staff education, call logs, EMR communications to parents/guardians, and careful chart review were employed. RESULTS: At the time of baseline MenACWY data collection, there were N = 333 subjects between 16 and 19 years of age and N = 335 subjects between 16 and 19 years of age provided for MenB data. Upon completion, there were N = 319 subjects. Comparison of pre- and post-intervention data demonstrated a statistically significant increase in MenACWY series completion from 67.3 to 76.2% (p = 0.035) and a non-statistically significant increase in MenB completion from 6.9 to 10.3% (p = 0.197). CONCLUSIONS: There was a statistically significant improvement in MenACWY but not MenB vaccination rates, indicating a need for more effective measures in addressing low MenB coverage.

Tolerability of MenACWY-TT vaccination in adolescents in the Netherlands; a cross-sectional study.

BACKGROUND: In 2018, meningococcal ACWY-TT vaccine (MenACWY-TT) was offered to adolescents in the Netherlands within the National Immunization Programme at 14 years of age. A questionnaire study assessed the tolerability of this vaccine. METHODS: Five thousand adolescents were invited to participate and to fill in two questionnaires about systemic events in the week before vaccination and local reactions and systemic events in the week after vaccination. Frequencies of local and systemic adverse events in the week after vaccination were calculated. Association between the occurrence of systemic symptoms in the week before and after the vaccination was tested by using generalized mixed models (GLMM). RESULTS: Of all adolescents, 139 returned one or both questionnaires. Any local reaction within 7 days after vaccination was reported by 55.6% of the adolescents. Pain (50%) and reduced use of the injected arm (21.3%) were most often reported. Any systemic event was reported by 67.6% of the participants, with myalgia as the most often reported event (37.0%). Compared with the week before vaccination, there were no increased odds of experiencing systemic symptoms in the week after vaccination (OR 0.95; 95%CI 0.40-2.27). CONCLUSIONS: After vaccination with MenACWY-TT vaccine, most adolescents reported one or more adverse events, which were mostly mild and transient. Systemic symptoms were not reported more often in the week after compared to the week before vaccination. Unfortunately, due to a low response rate we were not able to detect the absolute elevated risks the sample size calculation was based on. However, despite limited data, our results are in line with results from prelicensure data, and indicate that MenACWY-TT vaccination is well tolerated in adolescents.

Information needs during an emerging outbreak of meningococcal W135 disease in the Netherlands: a study among teenagers, their parents and healthcare professionals.

BACKGROUND: To counter the rise in invasive meningococcal disease (IMD) serogroup W, the Netherlands introduced a menACWY catch-up vaccination campaign for teenagers in 2018 and 2019. Teenagers and parents who have questions or who seek advice from a professional about vaccinations are likely to consult a youth healthcare professional or their general practitioner. This study aimed to appraise the ability of these healthcare professionals to meet the information needs of teenagers and their parents at the start of the vaccination campaign. METHODS: With online surveys, we assessed information needs in teenagers (N = 1603) and parents (N = 1784) concerning IMD and the menACWY vaccination, and in healthcare professionals (N = 520) in their communication with teenagers and parents. We additionally studied healthcare professionals' expectations of the information needs of teenagers and parents. RESULTS: We identified several information needs about IMD and the menACWY vaccination in teenagers, parents and healthcare professionals. Some important commonalities in the information needs in these three groups were found, with regard to the topics IMD prevention, vaccine effectiveness and vaccine protection duration. Healthcare professionals' expectations of the information needs of teenagers and parents were quite accurate but some important discrepancies were found. CONCLUSION: Our results suggest that healthcare professionals might not have been optimally equipped or prepared for questions from teenagers and their parents at the beginning of the vaccination campaign. We recommend public health institutes to timely assess and meet information needs about new vaccines in healthcare professionals to optimally equip them for consultations.

Case Manifestations and Public Health Response for Outbreak of Meningococcal W Disease, Central Australia, 2017.

Neisseria meningitidis serogroup W has emerged as an increasingly common cause of invasive meningococcal disease worldwide; the average case-fatality rate is 10%. In 2017, an unprecedented outbreak of serogroup W infection occurred among the Indigenous pediatric population of Central Australia; there were 24 cases over a 5-month period. Among these cases were atypical manifestations, including meningococcal pneumonia, septic arthritis, and conjunctivitis. The outbreak juxtaposed a well-resourced healthcare system against unique challenges related to covering vast distances, a socially disadvantaged population, and a disease process that was rapid and unpredictable. A coordinated clinical and public health response included investigation of and empiric treatment for 649 febrile children, provision of prophylactic antimicrobial drugs for 465 close contacts, and implementation of a quadrivalent meningococcal ACWY conjugate vaccine immunization program. The response contained the outbreak within 6 months; no deaths and only 1 case of major illness were recorded.

A phase 2b/3b MenACWY-TT study of long-term antibody persistence after primary vaccination and immunogenicity and safety of a booster dose in individuals aged 11 through 55 years.

BACKGROUND: A previous phase 2 study demonstrated the immunogenicity of a single dose of meningococcal A, C, W, Y-tetanus toxoid conjugate (MenACWY-TT) or polysaccharide (MenACWY-PS) vaccine for up to 5 years in individuals aged 11-55 years. This follow-up study evaluated long-term antibody persistence up to 10 years and the immunogenicity and safety of a single MenACWY-TT booster dose given 10 years after primary vaccination. METHODS: Blood draws were conducted annually in Years 7-10. At Year 10, all subjects received a MenACWY-TT booster dose. Blood was drawn at 1 month and safety data were collected ≤6 months postbooster. Study endpoints included immunogenicity during the persistence phase (primary), and immunogenicity and safety during the booster phase (secondary). Statistical analyses were descriptive. RESULTS: A total of 311 subjects were enrolled in the persistence phase (MenACWY-TT, 235; MenACWY-PS, 76); 220 were enrolled in the booster phase (MenACWY-TT, 164; MenACWY-PS, 56). Descriptive analyses indicated that at Years 7-10, the percentages of subjects achieving serum bactericidal antibody assay using baby rabbit complement (rSBA) titers ≥1:8 and ≥1:128 were higher for serogroups A, W, and Y in the MenACWY-TT versus MenACWY-PS group; percentages were similar across groups for serogroup C. rSBA geometric mean titers (GMTs) for serogroups A, W, and Y were higher in the MenACWY-TT group and slightly higher in the MenACWY-PS group for serogroup C. One month postbooster, all primary MenACWY-TT and ≥98.1% of primary MenACWY-PS recipients had rSBA titers ≥1:8. For all serogroups, rSBA GMTs postbooster were higher in the MenACWY-TT versus MenACWY-PS group. Most local and general reactogenicity events were similar between groups and mild to moderate in severity. Adverse events at 1 month postbooster were 9.1% for the MenACWY-TT and 3.6% for the MenACWY-PS groups; all were nonserious. CONCLUSIONS: Immune responses to a single MenACWY-TT primary dose administered at age 11-55 years persisted in >70% of individuals evaluated at Years 7-10. A MenACWY-TT booster dose administered at Year 10 was safe and immunogenic with no new safety signals observed. These results provide important insights regarding long-term protection from primary vaccination and the benefits of booster dosing. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01934140. Registered September 2013.

Safety of a quadrivalent meningococcal conjugate vaccine in healthy subjects aged 9 months to 55 years in Vietnam.

PURPOSE: Meningococcal disease is a major global health concern due to its severe and sudden clinical manifestations, devastating long-term sequelae, and predominance in younger age groups. This study evaluated the safety of a quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine (MenACWY-D; Menactra) in participants aged 9 months to 55 years in Vietnam. METHODS: This was an open-label, single-arm study conducted between June and December 2016. Participants received one 0.5-mL dose of the vaccine, and those aged 9 to 23 months received a second 0.5-mL dose 3 months later. Participants (or their parents or legal guardians) reported adverse events during the 28 days after each dose. RESULTS: The study included 112 participants aged 9 to 23 months and 112 participants aged 2 to 55 years. Of these 224 participants, 100 (44.6%) had one or more solicited reactions within 7 days following any MenACWY-D dose, mostly injection site pain, lost appetite (in 9 to 23-month-olds), and malaise (in 2 to 55-year-olds). Most solicited reactions were of mild or moderate intensity and resolved within 3 days. Five participants had unsolicited adverse reactions (ARs), two of which (tonsillitis and febrile convulsion), in 9 to 23-month-olds, were considered by the investigator as serious adverse events related to the vaccine. No immediate unsolicited ARs, severe unsolicited nonserious ARs, or unsolicited injection site reactions were reported, and both participants who experienced vaccine-related serious adverse events recovered. CONCLUSION: Consistent with studies in other countries, MenACWY-D had an acceptable safety profile in individuals from Vietnam aged 9 months to 55 years (WHO Universal Trial Number: U1111-1143-9207).

Did school characteristics affect the uptake of meningococcal quadrivalent vaccine in Greater Manchester, United Kingdom?

OBJECTIVES: The objective of this study was to assess if school characteristics were associated with the uptake of the meningococcal ACWY (MenACWY) vaccine in Greater Manchester in 2017/18. STUDY DESIGN: This is an ecological cross-sectional study. METHODS: We analysed data on all 129 schools in seven local authorities in Greater Manchester from the Department for Education and from local child health information systems to determine whether school characteristics, including school type and Ofsted effectiveness score, were associated with vaccine uptake. Schools with no eligible pupils were excluded. We undertook single-variable and multivariable analysis and considered key interactions. RESULTS: The overall uptake rate was 80.7%, with a median uptake per school of 80.6% (interquartile range, 69.0%-87.4%). Lower vaccination rates were associated with lower overall effectiveness scores (odds ratio [OR]: 3.54, 95% confidence interval [CI]: 3.00-4.19) and lower numbers of pupils eligible for vaccination (OR: 1.39, 95% CI: 1.28-1.51). Schools with a lower percentage of pupils for whom English is a second language and high deprivation were associated with lower uptake (OR: 1.58, 95% CI: 1.41-1.78). In addition, community schools (the schools with the most local authority oversight) had lower vaccination rates than other categories of schools. CONCLUSIONS: In this study, uptake rates of the MenACWY vaccine were associated with all five school characteristics considered. Effectiveness scores for schools had the largest association with vaccine uptake, with poorer schools having lower uptake. These characteristics should be used by vaccination providers to prioritise their interventions to increase immunisation rates.

Managing the risk of bacterial meningitis among healthcare workers.

BACKGROUND: Meningococcal disease is generally caused by A, B, C, W and Y subgroups of Neisseria meningitidis. In 2015, the Italian mass media focused on this disease due to the death of two nurses. This generated alarm in the general population, especially in healthcare workers (HCWs). The Occupational Medicine department of the Foundation PTV Polyclinic Tor Vergata (PTV) offered free MenACWY vaccine to HCWs and to students of the University of Rome Tor Vergata. AIMS: To analyse the prevalence of N. meningitidis in PTV, a large teaching hospital, and to evaluate preventive measures offered to individuals at risk (i.e. HCWs and students). METHODS: The Hospital Informatic Service provided data about patients admitted to PTV from January 2012 to December 2016. Hospital Discharge Registers were analysed and all cases of meningitis were selected. MenACWY vaccine administered to HCWs and students of PTV in 2017 was analysed. RESULTS: There was just one case of meningococcal disease in 2016. Of the 117 MenACWY vaccines administered, 42% were given to students, 32% to doctors, 8% to nurses, 2% to clerks and 16% to other healthcare professionals. CONCLUSIONS: International guidelines recommend MenACWY vaccine for microbiologists exposed to N. meningitidis isolates. The Italian Legislative Decree 81/2008, however, states that occupational physicians can adopt special protective measures such as vaccination programmes for HCWs. The response rate highlights how perceived risk may influence behaviour even in populations with a higher background knowledge than the general population.

Rise in Group W Meningococcal Carriage in University Students, United Kingdom.

MenACWY conjugate vaccination was recently introduced in the United Kingdom for adolescents and young adults to reduce disease from infection by Neisseria meningitidis group W. We conducted a cross-sectional meningococcal carriage study in first-year UK university students. Despite 71% MenACWY vaccine coverage, carriage of group W increased substantially.

Emergency Meningococcal ACWY Vaccination Program for Teenagers to Control Group W Meningococcal Disease, England, 2015-2016.

During the first 12 months of an emergency meningococcal ACWY vaccination program for teenagers in England, coverage among persons who left school in 2015, the first cohort to be vaccinated, was 36.6%. There were 69% fewer group W meningococcal cases than predicted by trend analysis and no cases in vaccinated teenagers.

A cluster of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup W among university students, France, February to May 2017.

Between February and May 2017, two cases of invasive meningococcal disease caused by a new, rapidly expanding serogroup W meningococci variant were reported among students of an international university in Paris. Bacteriological investigations showed that isolates shared identical genotypic formula (W:P1.5,2:F1-1:cc11) and belonged to the South American/UK lineage. A vaccination campaign was organised that aimed at preventing new cases linked to potential persistence of the circulation of the bacteria in the students.

Immunogenicity of meningococcal quadrivalent (serogroup A, C, W135 and Y) tetanus toxoid conjugate vaccine: systematic review and meta-analysis.

Meningococcal meningitis represents one of the leading cause of bacterial meningitis in developed countries. Among the thirteen described serogroups, only five are usually responsible of invasive infections making immunisation against multiple serogroups the best strategy to protect individuals from this disease. Herein we carried out a systematic review and meta-analysis, in accordance with the PRISMA statement, of the recently EU-licensed meningococcal ACWY-tetanus toxoid conjugate vaccine (MenACWY-TT). We included 15 randomised clinical trials, comparing MenACWY-TT and Men-PS (ten studies), MenACWY-TT and MenC-CRM197 (four studies) and MenACWY-TT and MenACWY-DT (one study). All studies included in the meta-analysis showed high immunogenicity for MenACWY-TT vaccines in all tested serogroups. Our results suggest that the MenACWY-TT vaccine is as immunogenic as the other commercial available meningococcal vaccines.

Antibody persistence and revaccination recommendations of MenACWY-TT: a review of clinical studies assessing antibody persistence up to 10 years after vaccination.

INTRODUCTION: Invasive meningococcal disease (IMD) is potentially fatal and associated with severe sequelae among survivors. It is preventable by several vaccines, including meningococcal vaccines targeting the most common disease-causing serogroups (A, B, C, W, Y). The meningococcal ACWY tetanus toxoid conjugate vaccine (MenACWY-TT [Nimenrix]) is indicated from 6 weeks of age in the European Union and >50 additional countries. AREAS COVERED: Using PubMed, Google Scholar, ClinicalTrials.gov and ad hoc searches for publications to June 2023, we review evidence of antibody persistence for up to 10 years after primary vaccination and up to 6 years after MenACWY-TT revaccination. We also review global MenACWY revaccination recommendations and real-world impact of vaccination policies, focusing on how these data can be considered alongside antibody persistence data to inform future IMD prevention strategies. EXPERT OPINION: Based on clear evidence that immunogenicity data (demonstrated antibody titers above established correlates of protection) are correlated with real-world effectiveness, long-term persistence of antibodies after MenACWY-TT vaccination suggests continuing protection against IMD. Optimal timing of primary and subsequent vaccinations is critical to maximize direct and indirect protection. Recommending bodies should carefully consider factors such as age at vaccination and long-term immune responses associated with the specific vaccine being used.