Lessons from mass vaccination response to meningococcal B outbreaks at US universities

Meningococcal Vaccination of Adolescents in the United States: Past Successes and Future Considerations

Invasive meningococcal disease (IMD) is a rare but serious illness, and adolescents and young adults in the United States are at increased risk. Here, we discuss US IMD history and how successful disease prevention through routine vaccination against the most common disease-causing serogroups (A, B, C, W, and Y) can inform future recommendations. Before the introduction of quadrivalent meningococcal conjugate (MenACWY) vaccines, most US cases of IMD were caused by serogroups B, C, and Y. After recommendation by the Advisory Committee on Immunization Practices for routine MenACWY vaccination of 11-12-year-olds in 2005, followed by a 2010 booster recommendation, MenCWY disease incidence declined dramatically, and vaccine coverage remains high. Two serogroup B (MenB) vaccines are licensed in the United States, but uptake is low compared with MenACWY vaccines, likely because Advisory Committee on Immunization Practices recommends MenB vaccination subject to shared clinical decision-making rather than routinely for all adolescents. The proportion of adolescent IMD caused by MenB has now increased. Pentavalent vaccines that protect against serogroups A, B, C, W, and Y may provide an optimal strategy for improving vaccination rates to ultimately reduce MenB incidence while maintaining the historically low rates of IMD caused by serogroups A, C, W, and Y.

The important lessons lurking in the history of meningococcal epidemiology

INTRODUCTION

The epidemiology of invasive meningococcal disease (IMD), a rare but potentially fatal illness, is typically described as unpredictable and subject to sporadic outbreaks.

AREAS COVERED

Meningococcal epidemiology and vaccine use during the last ~ 200 years are examined within the context of meningococcal characterization and classification to guide future IMD prevention efforts.

EXPERT OPINION

Historical and contemporary data highlight the dynamic nature of meningococcal epidemiology, with continued emergence of hyperinvasive clones and affected regions. Recent shifts include global increases in serogroup W disease, meningococcal antimicrobial resistance (AMR), and meningococcal urethritis; additionally, unvaccinated populations have experienced disease resurgences following lifting of COVID-19 restrictions. Despite these changes, a close analysis of meningococcal epidemiology indicates consistent dominance of serogroups A, B, C, W, and Y and elevated IMD rates among infants and young children, adolescents/young adults, and older adults. Demonstrably effective vaccines against all 5 major disease-causing serogroups are available, and their prophylactic use represents a powerful weapon against IMD, including AMR. The World Health Organization's goal of defeating meningitis by the year 2030 demands broad protection against IMD, which in turn indicates an urgent need to expand meningococcal vaccination programs across major disease-causing serogroups and age-related risk groups.

Serum bactericidal activity against circulating and reference strains of meningococcal serogroup B in the United States: A review of the strain coverage of meningococcal serogroup B (MenB) vaccines in adolescents and young adults

Invasive meningococcal disease (IMD) is rare but associated with high morbidity and mortality. In the United States, the most vulnerable age groups are infants and adolescents/young adults, and the most common type of IMD is caused by serogroup B (MenB). MenB is preventable among adolescents and young adults with the use of two licensed vaccines, MenB-FHbp (Trumenba®, bivalent rLP2086; Pfizer Inc, Collegeville, PA) and MenB-4C (Bexsero®; GSK Vaccines, Srl, Italy). Because the effectiveness of MenB vaccination is dependent on broad vaccine coverage across circulating disease-causing strains, we reviewed the available clinical and real-world evidence regarding breadth of coverage of the two licensed vaccines in adolescents and young adults in the United States. Both vaccines protect against various MenB strains. More controlled data regarding breadth of coverage across MenB strains are available for MenB-FHbp compared with MenB-4C, whereas more observational data regarding US outbreak strain susceptibility are available for MenB-4C.

Meningococcal B Immunisation in Adults and Potential Broader Immunisation Strategies: A Narrative Review

Recombinant vaccines against invasive meningococcal disease due to Neisseria meningitidis serogroup B (MenB) have shown substantial impact in reducing MenB disease in targeted populations. 4CMenB targets four key N. meningitidis protein antigens; human factor H binding protein (fHbp), Neisserial heparin binding antigen (NHBA), Neisseria adhesin A (NadA) and the porin A protein (PorA P1.4), with one or more of these expressed by most pathogenic MenB strains, while MenB-FHbp targets two distinct fHbp variants. While many countries recommend MenB immunisation in adults considered at high risk due to underlying medical conditions or immunosuppression, there are no recommendations for routine use in the general adult population. We reviewed the burden of MenB in adults, where, while incidence rates remain low (and far lower than in young children < 5 years of age at greatest risk), a substantial proportion of MenB cases (20% or more) is now observed in the adult population; evident in Europe, Australia, and in the United States. We also reviewed immunogenicity data in adults from clinical studies conducted during MenB vaccine development and subsequent post-licensure studies. A 2-dose schedule of 4CMenB generates hSBA titres ≥ 1:4 towards all four key vaccine target antigens in up to 98-100% of subjects. For MenB-FHbp, a ≥ fourfold rise in hSBA titres against the four primary representative test strains was observed in 70-95% of recipients following a 3-dose schedule. While this suggests potential benefits for MenB immunisation if used in adult populations, data are limited (especially for adults > 50 years) and key aspects relating to duration of protection remain unclear. Although a broader adult MenB immunisation policy could provide greater protection of the adult population, additional data are required to support policy decision-making.

National and regional differences in meningococcal vaccine recommendations for individuals at an increased risk of meningococcal disease

INTRODUCTION

Invasive meningococcal disease (IMD) is a severe, life-threatening condition caused by infection with Neisseria meningitidis. Currently available vaccines offer protection against the five most common meningococcal disease-causing serogroups and include monovalent and quadrivalent conjugate vaccines (MenA, MenC, MenACWY vaccines) and outer membrane vesicle- and/or recombinant protein-based vaccines (MenB vaccines).

AREAS COVERED

Country and regional immunization programs target populations susceptible to IMD and typically emphasize the highest-risk age groups (i.e., infants, adolescents/young adults, and the elderly); however, additional groups are also considered at an elevated risk and are the focus of the current review. Specific increased-risk groups include individuals with underlying immunocompromising medical conditions, university/college students, Indigenous people, laboratory workers, military personnel, men who have sex with men, and travelers to areas with hyperendemic IMD. This review compares established meningococcal vaccination recommendations for these vulnerable groups in Europe, the United States, Australia, New Zealand, Israel, Brazil, and Turkey.

EXPERT OPINION

Recommendations should be standardized to cover all groups at increased risk of IMD.

Rationale for the Development of a Pentavalent Meningococcal Vaccine: A US-Focused Review

While invasive meningococcal disease (IMD) is uncommon, it can result in serious sequelae and even death. In 2018 in the United States, the incidence of IMD per 100,000 people was 0.03 among adolescents 11−15 years of age, 0.10 among persons 16−23 years of age, and 0.83 among infants < 1 year of age. Serogroup B accounted for 86%, 62%, and 66% of cases, respectively, in those age groups. Currently, routine meningococcal vaccination covering serogroups ACWY (MenACWY) is recommended in the United States for all adolescents at 11−12 years of age, with a booster dose at 16 years of age, whereas a meningococcal serogroup B (MenB) vaccine series is recommended for persons 16−23 years of age under the shared clinical decision-making paradigm. The MenACWY vaccination program in adolescents has been successful in reducing disease burden, but does not prevent disease caused by serogroup B, which accounts for more than half of IMD cases. There are currently no approved vaccines that cover all of the most common disease-causing meningococcal serogroups, which are A, B, C, W, and Y. A pentavalent MenABCWY vaccine that is constituted from 2 licensed meningococcal vaccines—MenB-FHbp and MenACWY-TT—is being investigated in healthy persons ≥ 10–25 years of age. The addition of a MenABCWY vaccine is the next natural step in the incremental meningococcal immunization program in the United States to improve protection against the most common serogroup causing IMD, with no increase in the number of immunizations needed. With high uptake, routine use of MenABCWY could reduce IMD cases and associated mortality, the rate of long-term physical and psychosocial sequelae in survivors, and costs associated with controlling outbreaks, particularly on college campuses. A MenABCWY vaccine would also reduce the number of injections required for adolescents, potentially improving compliance.

Meningococcal Disease Outbreaks: A Moving Target and a Case for Routine Preventative Vaccination

Outbreaks of invasive meningococcal disease (IMD) are unpredictable, can be sudden and have devastating consequences. We conducted a non-systematic review of the literature in PubMed (1997-2020) to assess outbreak response strategies and the impact of vaccine interventions. Since 1997, IMD outbreaks due to serogroups A, B, C, W, Y and X have occurred globally. Reactive emergency mass vaccination campaigns have encompassed single institutions (schools, universities) through to whole sections of the population at regional/national levels (e.g. serogroup B outbreaks in Saguenay-Lac-Saint-Jean region, Canada and New Zealand). Emergency vaccination responses to IMD outbreaks consistently incurred substantial costs (expenditure on vaccine supplies, personnel costs and interruption of other programmes). Impediments included the limited pace of transmission of information to parents/communities/healthcare workers; issues around collection of informed consents; poor vaccine uptake by older adolescents/young adults, often a target age group; issues of reimbursement, particularly in the USA; and difficulties in swift supply of large quantities of vaccines. For serogroup B outbreaks, the need for two doses was a significant issue that contributed substantially to costs, delayed onset of protection and non-compliance with dose 2. Real-world descriptions of outbreak control strategies and the associated challenges systematically show that reactive outbreak management is administratively, logistically and financially costly, and that its impact can be difficult to measure. In view of the unpredictability, fast pace and potential lethality of outbreak-associated IMD, prevention through routine vaccination appears the most effective mitigation tool. Highly effective vaccines covering five of six disease-causing serogroups are available. Preparedness through routine vaccination programmes will enhance the speed and effectiveness of outbreak responses, should they be needed (ready access to vaccines and need for a single booster dose rather than a primary series).

Increasing awareness and uptake of the MenB vaccine on a large university campus

Objective: At a large public university, we aimed to evaluate an intervention designed to increase serogroup B meningococcal (MenB) vaccine uptake and awareness.Methods: Using a pretest-posttest design with a double posttest, we evaluated an intervention conducted by a local foundation and the Florida Department of Health that distributed MenB vaccine on campus and conducted an educational campaign. Prior to intervention activities, we recruited students to complete a survey about their MenB knowledge and attitudes. For survey participants who provided contact information, we sent two follow-up surveys and assessed MenB vaccine records. We used chi-square tests, adjusted for nonindependence, to compare preintervention to postintervention (three-month and one-year) vaccination and attitudes.Results: Among the 686 students with accessible vaccine records, MenB vaccine initiation increased 9% (from 24% to 33%) and completion increased 8% (from 13% to 21%) from before the intervention to one year after the intervention. When restricting to students who completed the relevant follow-up surveys, the percentage of students who heard of the MenB vaccine increased by 15% (p > .001) from before the intervention to three months after (n = 188 students) and maintained a 10% increase (p > .001) one year after the intervention (n = 261 students). Among students that heard of the MenB vaccine, the percentage of students who thought they needed the MenB vaccine even though they received the MenACWY increased 14% (p = .03) by the three-month postintervention survey and up to 18% by the one-year follow-up (p = .002).Conclusions: A university-wide, on-campus vaccination and educational campaign increased college students' MenB vaccine initiation, completion, and knowledge.Clinicaltrials.gov ID: NCT02975596.