Zilucoplan (Zilbrysq) for myasthenia gravis

The FDA has approved the complement C5 inhibitor zilucoplan (Zilbrysq – UCB) for once-daily subcutaneous treatment of generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) antibody-positive. Zilucoplan is the first complement inhibitor to be approved for treatment of myasthenia gravis that can be self-administered.

Neisseria meningitidis on Sinonasal Culture for Sinusitis: A Case Series and Literature Review

Neisseria meningitidis is carried asymptomatically in the nasopharynx and is most known for causing septicemia and meningitis; however, the pathogenesis and incidence rates of N. meningitidis sinusitis are not well described. This case series describes four patients from a tertiary medical center who presented with culture-positive N. meningitidis sinusitis within a nine-month period. Three patients had complete resolution of symptoms after treatment with the appropriate antibiotic regimen, with one patient requiring functional endoscopic sinus surgery. We encourge providers to advocate for vaccination in their young adult unvaccinated patients, as each patient here was not appropriately vaccinated according to CDC guidelines. Laryngoscope, 134:1603-1605, 2024.

Neisseria gonorrhoeae lipooligosaccharide glycan epitopes recognized by bactericidal IgG antibodies elicited by the meningococcal group B-directed vaccine, MenB-4C

Introduction

Outer membrane vesicles (OMVs) of Neisseria meningitidis in the group B-directed vaccine MenB-4C (BexseroR) protect against infections with Neisseria gonorrhoeae. The immunological basis for protection remains unclear. N. meningitidis OMV vaccines generate human antibodies to N. meningitidis and N. gonorrhoeae lipooligosaccharide (LOS/endotoxin), but the structural specificity of these LOS antibodies is not defined.

Methods

Ten paired human sera obtained pre- and post-MenB-4C immunization were used in Western blots to probe N. meningitidis and N. gonorrhoeae LOS. Post-MenB-4C sera (7v5, 19v5, and 17v5), representing individual human variability in LOS recognition, were then used to interrogate structurally defined LOSs of N. meningitidis and N. gonorrhoeae strains and mutants and studied in bactericidal assays.

Results and discussion

Post-MenB-4C sera recognized both N. meningitidis and N. gonorrhoeae LOS species, ~10% of total IgG to gonococcal OMV antigens. N. meningitidis and N. gonorrhoeae LOSs were broadly recognized by post-IgG antibodies, but with individual variability for LOS structures. Deep truncation of LOS, specifically a rfaK mutant without α-, β-, or γ-chain glycosylation, eliminated LOS recognition by all post-vaccine sera. Serum 7v5 IgG antibodies recognized the unsialyated L1 α-chain, and a 3-PEA-HepII or 6-PEA-HepII was part of the conformational epitope. Replacing the 3-PEA on HepII with a 3-Glc blocked 7v5 IgG antibody recognition of N. meningitidis and N. gonorrhoeae LOSs. Serum 19v5 recognized lactoneotetrose (LNT) or L1 LOS-expressing N. meningitidis or N. gonorrhoeae with a minimal α-chain structure of Gal-Glc-HepI (L8), a 3-PEA-HepII or 6-PEA-HepII was again part of the conformational epitope and a 3-Glc-HepII blocked 19v5 antibody binding. Serum 17v5 LOS antibodies recognized LNT or L1 α-chains with a minimal HepI structure of three sugars and no requirement for HepII modifications. These LOS antibodies contributed to the serum bactericidal activity against N. gonorrhoeae. The MenB-4C vaccination elicits bactericidal IgG antibodies to N. gonorrhoeae conformational epitopes involving HepI and HepII glycosylated LOS structures shared between N. meningitidis and N. gonorrhoeae. LOS structures should be considered in next-generation gonococcal vaccine design.

Bioinformatics Analysis of Global Diversity in Meningococcal Vaccine Antigens over the Past 10 Years: Vaccine Efficacy Prognosis

Neisseria meningitidis (N. meningitidis) serogroup B (MenB) is the leading cause of invasive meningococcal disease worldwide. The pathogen has a wide range of virulence factors, which are potential vaccine components. Studying the genetic variability of antigens within a population, especially their long-term persistence, is necessary to develop new vaccines and predict the effectiveness of existing ones. The multicomponent 4CMenB vaccine (Bexsero), used since 2014, contains three major genome-derived recombinant proteins: factor H-binding protein (fHbp), Neisserial Heparin-Binding Antigen (NHBA) and Neisserial adhesin A (NadA). Here, we assessed the prevalence and sequence variations of these vaccine antigens in a panel of 5667 meningococcal isolates collected worldwide over the past 10 years and deposited in the PubMLST database. Using multiple amino acid sequence alignments and Random Forest Classifier machine learning methods, we estimated the potential strain coverage of fHbp and NHBA vaccine variants (51 and about 25%, respectively); the NadA antigen sequence was found in only 18% of MenB genomes analyzed, but cross-reactive variants were present in less than 1% of isolates. Based on our findings, we proposed various strategies to improve the 4CMenB vaccine and broaden the coverage of N. meningitidis strains.

A National Advisory Committee on Immunization (NACI) update on invasive meningococcal disease (IMD) epidemiology and program-relevant considerations for preventing IMD in individuals at high risk of exposure

Following recent outbreaks of invasive meningococcal disease (IMD) in Canada and updates to provincial vaccination guidelines, the National Advisory Committee on Immunization (NACI) conducted a targeted review of evidence with a focus on immunization of adolescents and young adults. NACI reviewed national and international immunization recommendations for populations at high-risk of IMD, national IMD epidemiology and program-relevant considerations. Given the varied IMD epidemiology, NACI determined that recommending a pan-Canadian targeted program is currently challenging and that regional programs may be better suited to prevent IMD in population groups considered to be at high-risk of exposure. Further data is needed to ascertain contemporary risk factors for IMD (including activities and settings associated with bacterial acquisition, carriage and transmission) and estimate the true cost of meningococcal vaccine-preventable infections in Canada. To support provinces and territories in their decision-making, an outline of program-relevant elements for provincial and territorial consideration is provided.

Real-world impact and effectiveness of MenACWY-TT

In response to escalating cases of serogroup W (MenW) invasive meningococcal disease (IMD), multiple countries introduced quadrivalent conjugate MenACWY vaccines into their national immunization programs (NIPs). Here, we summarize the real-world impact and vaccine effectiveness (VE) data of MenACWY-TT from Chile, England, the Netherlands, and Australia. Incidence rate reductions (IRRs) and VE from baseline to post-NIP period were extracted from publications or calculated. After the administration of a single dose of MenACWY-TT, substantial IRRs of MenCWY were observed across the countries in vaccine-eligible age groups (83%-85%) and via indirect protection in non-vaccine-eligible age groups (45%-53%). The impact of MenACWY-TT was primarily driven by MenW IRRs, as seen in vaccine-eligible age groups (65%-92%) and non-vaccine-eligible age groups (41%-57%). VE against MenW was reported in vaccine-eligible toddlers (92%) in the Netherlands and in vaccine-eligible adolescents/young adults (94%) in England. These real-world data support the implementation and continued use of MenACWY-TT in NIPs.

Serogroup B Meningococcal Sepsis and Meningitis Associated With Meningococcal Acute Otitis Media, and Paranasal Sinusitis in an Infant: A Case Report

Meningococcal disease (MD) is a potentially lethal condition. Typically, following infection, MD manifests with high fever, with signs and symptoms of severe septicemia with or without purpura, and in more than half of cases with meningitis. Acute otitis media (AOM) caused by Neisseria meningitidis has scarcely been reported, mostly without severe MD, and there are no reports of meningococcal paranasal sinusitis (PS). We present the case of a previously healthy 11-month-old infant who started with fever and cough and further developed intense irritability and right spontaneous purulent otorrhea, with subsequent increased fever and seizures. Blood, cerebrospinal, and middle ear fluid cultures were positive for N. meningitidis serogroup B, and a CT scan showed both maxillary and ethmoidal sinusitis. Intravenous ceftriaxone was administered for eight days, and three months following discharge, no sequelae were identified. This is the first report of a patient with MD associated with sepsis, meningitis, AOM, and PS.

Efficacy and Safety of Quadrivalent Conjugate Meningococcal Vaccines: A Systematic Review and Meta-Analysis

Over the last decades, different quadrivalent antimeningococcal vaccine formulations (diphteria toxoid conjugate, MenACWY-D; tetanus toxoid conjugate, MenACWY-TT; CRM₁₉₇ protein conjugate, MenACWY-CRM) have been developed. However, their availability varies, both in terms of authorized formulations and of inclusion in vaccination schedules. Furthermore, several countries include only the monovalent meningococcal C (MenC) vaccine in their immunization programmes. Finally, there is currently no updated systematic review that directly compares the MenACWY formulations. Thus, we summarized the evidence on efficacy and safety through four parallel, independent systematic literature reviews with meta-analysis which included randomized controlled trials comparing the abovementioned vaccines. A total of 16 studies have been included. In terms of efficacy, MenACWY-TT outperformed MenACWY-D and MenACWY-CRM for A, W-135, and Y serogroups, while no significant difference was found for serogroup C. Furthermore, we did not find significant differences in efficacy between MenC and MenACWY-TT. Regarding the safety, we were able to perform a quantitative analysis only between MenACWY-TT and MenC, finding no significant differences. Similarly, among the different MenACWY formulations no relevant differences were identified. These findings suggest that MenACWY-TT could be preferable to other formulations to improve current vaccination programs and to better develop future immunization policies.

Contralateral Recurrences of Post-vaccination Multiple Evanescent White Dot Syndrome

We report on a case of multiple evanescent white dot syndrome (MEWDS) following the simultaneous administration of the human papillomavirus and meningococcal (conjugate) vaccines and two recurrences of MEWDS following the administration of the second dose of the human papillomavirus (HPV) vaccine and the COVID-19 vaccine and COVID-19 viral infection. A 17-year-old Hispanic female presented with a one-week history of photopsia and blurred vision in her left eye following the simultaneous administration of the human papillomavirus and meningococcal (conjugate) vaccines. Upon a comprehensive examination, her best-corrected visual acuity was 20/20 in the right eye and 20/100 in the left eye. A left fundus examination revealed multiple white dots in the macula and nasal periphery, consistent with a diagnosis of MEWDS. Ancillary testing, including fundus autofluorescence, fluorescein angiography, indocyanine green angiography, and optical coherence tomography, supported the diagnosis. One month following her initial diagnosis, the patient's symptoms had resolved without any therapy, and a fundus examination revealed multiple relatively ill-defined brown-colored subretinal lesions in the nasal midperiphery, corresponding to the location of the previous MEWDS lesions. Subsequently, she received the second dose of the HPV vaccine and then developed a mild COVID-19 infection. Four months after the initial presentation, she received the first dose of the BNT162b2 COVID-19 vaccine, followed by the second dose a month later. Eight months following her initial presentation, she presented with photopsia in the right eye. Her visual acuity remained 20/20 in the right eye and improved to 20/20 in the left eye, and white dots were identified nasal to the disk and surrounding the peripapillary region; the contralateral MEWDS diagnosis was confirmed by the previously mentioned ancillary tests. At her one-month follow-up, she presented new onset photopsia of the right eye. Her visual acuity remained 20/20 in both eyes, and a fundus examination revealed white lesions suggestive of active MEWDS temporal to the macula and brown-colored spots nasal to the disk, suggestive of recovering MEWDS, nasally. The aforementioned testing confirmed the coexistence of new and resolving lesions; nonetheless, the patient's symptoms resolved without any therapy, and she received the third dose of the BNT162b2 COVID-19 vaccine 11 months after her initial presentation. Our case suggests that vaccines may serve as immunological triggers of MEWDS. Recurrent MEWDS may occur when an individual is exposed to a powerful immune challenge, such as receiving a wide array of vaccinations in a short period of time. We believe this case constitutes a previously undescribed finding of multiple relatively ill-defined brown-colored subretinal lesions present in late MEWDS.

Vaccine Uptake to Prevent Meningitis and Encephalitis in Shanghai, China

Multiple vaccines may prevent meningitis and encephalitis (M/E). In China, the meningococcal vaccine and Japanese encephalitis vaccine (JEV) have been included in the expanded program of immunization (EPI). The pneumococcal vaccine, Haemophilus influenzae type b (Hib) vaccine, rotavirus vaccine, and enterovirus 71 (EV-71) vaccine are non-EPI vaccines and are self-paid. We aim to investigate the uptake of these M/E vaccines in children and the related knowledge and health beliefs among family caregivers. A total of 1011 family caregivers with children aged 1-6 years in Shanghai, China were included in the study. The uptake of the pneumococcal vaccine, Hib-containing vaccine, rotavirus vaccine, and EV-71 vaccine remained at 44.0-48.1% in children, compared with the higher uptake of the meningococcal vaccine (88.8%) and JEV (87.1%). Moreover, family caregivers had limited knowledge on the M/E pathogens and possible vaccines. Their health beliefs were moderate to high. Then, a health belief model (HBM) and a structural equation model were established. The uptake of four non-EPI vaccines was significantly influenced by family income (β = 0.159), knowledge (β = 0.354), self-efficacy (β = 0.584), and perceived susceptibility (β = 0.212) within an HBM. Therefore, it warrants further improving the uptake rate for these non-EPI vaccines to prevent potential M/E in children. A specific health promotion may empower the caregivers' decision-making on childhood vaccination.

Effect of Hurricane Maria on HPV, Tdap, and meningococcal conjugate vaccination rates in Puerto Rico, 2015-2019

In September 2017, Hurricane Maria devastated the Caribbean region, among them the US territory of Puerto Rico (PR). Vaccination distribution and uptake suffered from the impact. This study evaluated the trends in monthly vaccination initiation rates for human papilloma virus (HPV), Tdap and meningococcal conjugate (MenACWY) adolescent vaccines from 2015 to 2019, during which it was possible to observe and analyze the impact of Hurricane Maria on vaccine initiation. Monthly initiation rates were estimated. Age-standardized initiation rate ratio (SRR) and 95% CI were estimated. The analysis included 85,340 adolescents; 52.3% were male, and 47.7% were females. September 2017 showed HPV vaccine initiation had the lower rates of all the studied vaccines, with a rate of 75% after the disaster (from a rate of almost 90% in July 2017). Tdap and MenACWY vaccines rates remained above 90% in the same period. The SRR of HPV vaccine for September and October 2017 showed an estimated reduction of 5% and 8% in vaccine initiation rates, respectively for each month, when 2016 was the reference year (p > .05). The SRR of Tdap and MenACWY vaccines for November 2017 showed significant reductions when 2015 and 2016 were reference years (p < .05). HPV vaccine initiation rate was the most severely affected by the Hurricane Maria. Post-natural disaster protocols should strengthen existing programs for facilitate immunization access.

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.

Randomized Trial of 2 Schedules of Meningococcal B Vaccine in Adolescents and Young Adults, Canada1

Emergency vaccination programs often are needed to control outbreaks of meningococcal disease caused by Neisseria meningitidis serogroup B (MenB) on college campuses. Such campaigns expend multiple campus and public health resources. We conducted a randomized, controlled, multicenter, observer-blinded trial comparing immunogenicity and tolerability of an accelerated vaccine schedule of 0 and 21 days to a longer interval of 0 and 60 days for 4-component MenB vaccine (MenB-4C) in students 17-25 years of age. At day 21 after the first MenB-4C dose, we observed protective human serum bactericidal titers >4 to MenB strains 5/99, H44/76, and NZ 98/254 in 98%-100% of participants. Geometric mean titers increased >22-fold over baseline. At day 180, >95% of participants sustained protective titers regardless of their vaccine schedule. The most common adverse event was injection site pain. An accelerated MenB-4C immunization schedule could be considered for rapid control of campus outbreaks.

Association between circulating exhausted CD4+ T cells with poor meningococcal C conjugate vaccine antibody response in HIV-infected children and adolescents

OBJECTIVES

To investigate the expression levels of surface markers of activation (CD38 and HLA-DR), inhibition (PD-1, TIGIT and CD57) and co-stimulation (CD28 and CD127) on CD4+ T cells of children/adolescents with vertical HIV infection (HI patients) and HIV-uninfected (HU) controls vaccinated with the meningococcal C conjugate vaccine (MCC).

METHODS

HI patients (n=12), aged 8-17 years, were immunized with two MCC injections, while HU controls (n=9), aged 5.3-10.7 years, received a single MCC dose (as per national recommendation at the time of this study, a single MCC vaccine dose should be given for healthy children and youth aged 1-18 years). The HI patients were categorized according to the combined antiretroviral therapy (cART) treatment. Blood samples were obtained before vaccination, after priming, and after the administration of a booster dose of vaccine to determine the serum bactericidal antibody (SBA) titers and the expression levels of surface markers on CD4+ T cells by flow cytometry. The levels of serum cytokines, IL-4 and CXCL-13 were also measured using Luminex kits.

RESULTS

The co-expression of the TIGIT-HLA-DR-CD38 molecules increased in the CD4+ T cells of HI patients/no-cART who also showed a lower frequency of CD127+CD28+ CD4+ T cells than HI patients/cART and HU group subjects. There were significant negative correlations between the frequency of exhausted CD4+ T cells and the SBA response. IL-4 levels were higher in HI patients/cART and positively correlated with SBA titers but negatively associated with the expression of exhaustion markers. Moreover, the CXCL-13 levels were positively correlated with the exhausted CD4+ T cells.

CONCLUSION

The results of our study suggest that the co-expression of exhaustion markers and/or loss of co-stimulatory molecules influence the SBA response in HI patients.

Herd Protection against Meningococcal Disease through Vaccination

Reduction in the transmission of Neisseria meningitidis within a population results in fewer invasive disease cases. Vaccination with meningococcal vaccines composed of high weight capsular polysaccharide without carrier proteins has minimal effect against carriage or the acquisition of carriage. Conjugate vaccines, however, elicit an enhanced immune response which serves to reduce carriage acquisition and hinder onwards transmission. Since the 1990s, several meningococcal conjugate vaccines have been developed and, when used in age groups associated with higher carriage, they have been shown to provide indirect protection to unvaccinated cohorts. This herd protective effect is important in enhancing the efficiency and impact of vaccination. Studies are ongoing to assess the effect of protein-based group B vaccines on carriage; however, current data cast doubt on their ability to reduce transmission.

The Serogroup B Meningococcal Vaccine Bexsero Elicits Antibodies to Neisseria gonorrhoeae

Background

Neisseria gonorrhoeae and Neisseria meningitidis are closely-related bacteria that cause a significant global burden of disease. Control of gonorrhoea is becoming increasingly difficult, due to widespread antibiotic resistance. While vaccines are routinely used for N. meningitidis, no vaccine is available for N. gonorrhoeae. Recently, the outer membrane vesicle (OMV) meningococcal B vaccine, MeNZB, was reported to be associated with reduced rates of gonorrhoea following a mass vaccination campaign in New Zealand. To probe the basis for this protection, we assessed the cross-reactivity to N. gonorrhoeae of serum raised to the meningococcal vaccine Bexsero, which contains the MeNZB OMV component plus 3 recombinant antigens (Neisseria adhesin A, factor H binding protein [fHbp]-GNA2091, and Neisserial heparin binding antigen [NHBA]-GNA1030).

Methods

A bioinformatic analysis was performed to assess the similarity of MeNZB OMV and Bexsero antigens to gonococcal proteins. Rabbits were immunized with the OMV component or the 3 recombinant antigens of Bexsero, and Western blots and enzyme-linked immunosorbent assays were used to assess the generation of antibodies recognizing N. gonorrhoeae. Serum from humans immunized with Bexsero was investigated to assess the nature of the anti-gonococcal response.

Results

There is a high level of sequence identity between MeNZB OMV and Bexsero OMV antigens, and between the antigens and gonococcal proteins. NHBA is the only Bexsero recombinant antigen that is conserved and surfaced exposed in N. gonorrhoeae. Bexsero induces antibodies in humans that recognize gonococcal proteins.

Conclusions

The anti-gonococcal antibodies induced by MeNZB-like OMV proteins could explain the previously-seen decrease in gonorrhoea following MeNZB vaccination. The high level of human anti-gonococcal NHBA antibodies generated by Bexsero vaccination may provide additional cross-protection against gonorrhoea.

First real world evidence of meningococcal group B vaccine, 4CMenB, protection against meningococcal group W disease; prospective enhanced national surveillance, England

BACKGROUND

4CMenB is a protein-based meningococcal group B vaccine but the vaccine antigens may also be present on non-group B meningococci. In September 2015, the UK implemented 4CMenB into the national infant immunisation programme, alongside an emergency adolescent meningococcal ACWY (MenACWY) programme to control a national outbreak of group W (MenW) disease caused by a hypervirulent strain belonging to the ST11 clonal complex. The adolescent programme aimed to provide direct protection for adolescents and, over time, indirect (herd) protection across the population.

METHODS

Public Health England conducts meningococcal disease surveillance in England. MenW cases confirmed during four years before and four years after implementation of both vaccines were analysed. Poisson models were constructed to estimate direct protection against MenW disease offered by the infant 4CMenB programme on top of the indirect impact of the adolescent MenACWY programme in children eligible for 4CMenB but not MenACWY.

RESULTS

Model estimates showed 69% (adjusted incidence rate ratio (IRR) 0.31, 95%CI, 0.20-0.67) and 52% (aIRR 0.48, 95%CI 0.28-0.81) fewer MenW cases than predicted among age-cohorts that were fully-eligible and partly-eligible for 4CMenB, respectively. There were 138 MenW cases in &5 year-olds. 4CMenB directly prevented 98 (95%CI, 34-201) cases, while the MenACWY programme indirectly prevented an additional 114 (conservative) to 899 (extreme) cases over four years. Disease severity was similar in 4CMenB-immunised and unimmunised children.

CONCLUSIONS

Our results provide the first real-world evidence of the direct protection afforded by 4CMenB against MenW:cc11 disease. 4CMenB has the potential to provide some protection against all meningococcal serogroups.

Effect of complement Factor H on antibody repertoire and protection elicited by meningococcal capsular group B vaccines containing Factor H binding protein

Bacteria produce surface ligands for host complement regulators including Factor H (FH), which allows the bacteria to evade immunity. Meningococcal Factor H binding protein (FHbp) is both a virulence factor and a vaccine antigen. Antibodies to FHbp can neutralize its function by inhibiting binding of FH to the bacteria and confer robust complement-mediated protection. However, in the presence of human or primate FH, antibodies to FHbp do not inhibit FH binding and the protective antibody responses are decreased. This immune suppression can be overcome by modification of the FHbp antigen to decrease FH binding, which modulates the antibody repertoire to inhibit FH binding and increase protection. When FHbp is present at sufficient density on the bacterial surface, two or more antibodies can synergize to activate the complement system. Thus, modification of FHbp antigens to decrease FH binding expands the anti-FHbp antibody repertoire and increases the potential for synergistic activity.

Summary of the NACI Statement on the Use of Bivalent Factor H Binding Protein Meningococcal Serogroup B (MenB-fHBP) Vaccine for the Prevention of Meningococcal B Disease

BACKGROUND

TrumenbaTM, a bivalent, factor-H binding protein meningococcal serogroup B (MenB-fHBP) vaccine was authorized for use in Canada in October 2017 for the prevention of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup B in individuals 10-25 years of age. The National Advisory Committee on Immunization (NACI) provides recommendations regarding the use of meningococcal vaccines to the Public Health Agency of Canada.

OBJECTIVE

To summarize NACI recommendations regarding the use of MenB-fHBP vaccine in Canada.

METHODS

The NACI Meningococcal Disease Working Group developed a predefined search strategy to identify all eligible studies, assessed the quality of these studies, and summarized and analyzed the findings. According to the NACI evidence-based process, the working group then proposed recommendations and identified the grade of evidence that supported them. In light of the evidence, the recommendations were then considered and approved by NACI.

RESULTS

The two serogroup B meningococcal vaccines currently authorized for use in Canada are not interchangeable as they contain different antigens and there are no published studies on the immunogenicity resulting from a vaccination series combining the two products. Following the review of evidence, NACI recommends that MenB-fHBP vaccine may be considered as an option for use in individuals 10 years of age and older in situations when a serogroup B meningococcal vaccine should be offered: 1) during serogroup B meningococcal disease outbreaks or with the emergence of hyperendemic N. meningitidis strains that are predicted to be susceptible to the vaccine; 2) for individuals who are close contacts with a case of invasive meningococcal disease caused by serogroup B N. meningitidis; 3) for individuals with underlying medical conditions that would put them at higher risk of meningococcal disease than the general population; or 4) for individuals at higher risk of exposure to serogroup B meningococcal isolates than the general population. NACI also recommends that MenB-fHBP vaccine may be considered as an option for individuals 10-25 years of age who are not at higher risk of meningococcal disease than the general population, but who wish to reduce their risk of invasive serogroup B meningococcal disease.

CONCLUSION

NACI recommends immunization against serogroup B IMD for all individuals who are at a higher risk of disease due to an underlying medical condition or an increased risk of exposure. In addition to providing guidance to public health decision-makers (i.e. provinces/territories making decisions for publicly-funded immunization programs), these NACI recommendations provide information to individuals, vaccine providers and organizations about vaccines that may not currently be included in publicly funded immunization programs. NACI continues to recommend against the use of the serogroup B vaccines in routine universal immunization programs in Canada at this time.

Naval Health Research Center Surveillance for Meningococcal Disease

Historically, meningococcal disease has had a devastating impact on U.S. military personnel, but since the introduction of a vaccine in the 1970s, rates have dropped over 90%.1 Department of Defense instructions mandate a meningococcal vaccine for all service personnel. In the last 5 years, rates of meningococcal disease in the military are similar to the U.S. general population. The active duty incidence was 0.21 cases per 100,000 person-years from 2013-2017. Six cases occurred in the 6 months between September 2016 and February 2017; of these, only one was determined to be a vaccine-covered strain. Ongoing surveillance shows vaccination has resulted in a dramatic reduction in meningococcal cases in the military; however, it also demonstrates cases continue to occur sporadically. The recent emergence of new cases reminds us that surveillance and accompanying research are important for evaluating changes in the disease and informing new vaccine development and policy.

Immunogenicity and safety of meningococcal group A, C, W and Y tetanus toxoid conjugate vaccine: review of clinical and real-world evidence

Protection by meningococcal group A, C, W and Y (MenACWY) vaccines against four meningococcal disease-causing serogroups is increasingly important because of changing epidemiologic patterns of meningococcal disease, including recent meningococcal serogroup W outbreaks/disease clusters. The MenACWY vaccine conjugated to tetanus toxoid (MenACWY-TT) has been extensively evaluated across the age spectrum (age ≥6 weeks) in randomized Phase II and III and in postmarketing studies. Results support the robust immunogenicity of MenACWY-TT across ages and coadministration with other vaccines. The safety profile is similar regardless of age, primary versus booster vaccination, or concomitant administration; local (swelling, pain, redness) and systemic (fever, fatigue, headache, drowsiness, loss of appetite, irritability) reactogenicity events are most common. These data support use of MenACWY-TT to protect against MenACWY disease.

Relative contributions of parental intention and provider recommendation style to HPV and meningococcal vaccine receipt

We described the relative contributions of parental intention and provider recommendation style to HPV and meningococcal vaccine receipt. Parent-child dyads that were eligible for both meningococcal and HPV vaccines participated in pre-visit surveys and consented to audio recording of their clinical interactions with healthcare providers related to vaccination. Surveys were analyzed for parent and child demographics and parental intention to vaccinate children with HPV and/or meningococcal vaccines. Audio recordings were analyzed for provider recommendation style, defined as indicated (provider stated vaccine was due at that visit) or not, and for child receipt of vaccines. Linear and logistic regression models were used to determine the relative contributions of parental intention and provider recommendation style to vaccine receipt. 56 parents/child dyads participated. 79% of children received HPV vaccines, and 93% received meningococcal vaccines. After controlling for demographic variables, parental intention did not differ by vaccine type. However, providers were less likely to use an indicated recommendation for HPV than for meningococcal vaccine. After controlling for demographic factors, parental intention, and provider recommendation style, vaccine type (HPV or meningococcal) was no longer associated with vaccine receipt Differences that were previously attributed to vaccine-specific factors may be explained by parents' and providers' roles in vaccine receipt. These findings suggest that interventions and policy recommendations regarding adolescent vaccination should focus on increasing parental demand for vaccines and ensuring that providers present all vaccines as the medical standard of care.

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).

The attitudes, behaviors, and knowledge of healthcare professionals towards the diagnosis, treatment, and prevention of bacterial meningitis in Turkey

INTRODUCTION

Bacterial meningitis is one of the leading causes of morbidity and mortality among children and adults. Better understanding of the seroepidemiology of meningitis is critical for both the selection and implementation of an effective meningitis vaccine for the national immunization program. Because physicians play a crucial role in the implementation of this vaccine, the aim of this study was to evaluate the attitudes, behaviors, and knowledge of healthcare professionals in Turkey regarding the diagnosis, treatment and prevention of bacterial meningitis, especially pneumococcal and meningococcal meningitis.

METHODS

This study used a cross-sectional electronic survey with a national convenience sample of 339 physicians (171 pediatric age specialists [PAS] and 168 adult patient specialists [APS]) in Turkey. A web-based questionnaire which consisted 28 questions about the definition, diagnosis, and treatment of bacterial as well as knowledge and/or attitudes about meningococcal vaccines, was designed.

RESULTS

Approximately 72.9% (n = 247) of the respondents followed a patient with meningitis in the last year. A 49.5% of participants preferred to perform computerized cranial tomography (CCT) for suspected meningitis cases before lumbar puncture (LP) at 75-100% frequency (27.5% PAS; 72% APS, p < .01). In addition 27.1% of the respondents reported using a routine steroid as an adjunctive treatment (19% PAS; 35% APS, p < .01). For meningococcal meningitis, 72.5% of the participants preferred to use third-generation cephalosporins (63.1% PAS; 82.1% APS, p < .05). For pneumococcal meningitis, approximately 50% of the participants preferred to use a third-generation cephalosporin plus glycopeptide (41.5% PAS; 58.9% APS, p < .05). While 32.7% of the sample preferred to administer a 7-day course of antibiotics for meningococcal meningitis, 40.9% preferred a course of 14 days or more. For pneumococcal meningitis, 88.4% of the sample preferred a 10-14 day course of antibiotics. In addition, 67% of the PAS group and 50% (p < .001) of the APS group thought that a conjugated meningococcal vaccine should be a part of the National Immunization Program. The top five groups recommended for routine immunization included all children, asplenia/splenectomy patients, immunodeficient patients, those who planned to travel to endemic areas, including Hajj, and military personnel.

CONCLUSION

In this large convenient sample of physicians in Turkey, we showed that there are heterogenous approaches to the diagnosis and treatment of bacterial meningitis, also differences between pediatricians and non-pediatricians regarding their beliefs and attitudes, which may be due to differences in the epidemiology and clinical presentation between children and adults. We observed appropriate but unnecessary extended courses of antibiotics for meningitis. Most of the participants thought that children are a vulnerable risk group that should potentially be immunized and that meningococcal vaccines should be included in the National Immunization Program. Our results imply that more awareness is needed regarding diagnosis, treatment, and further recommendations for meningitis at the country level in Turkey.

Invasive meningococcal disease epidemiology and characterization of Neisseria meningitidis serogroups, sequence types, and clones; implication for use of meningococcal vaccines

BACKGROUND AND AIMS

Neisseria meningitidis (N. meningitidis) is a Gram-negative bacterium that can cause life-threatening invasive infections referred to as invasive meningococcal disease (IMD). In the last decade the incidence of IMD in Israel is about 1/100,000 population annually. We aimed to describe the epidemiology of IMD in Israel combining epidemiological data and characterization of N. meningitidis isolates.

METHODS

Invasive infection caused by N. meningitidis is a notifiable disease in Israel. Data were collected by epidemiological investigations and control measures were employed. Laboratory work-up included serogrouping, N. meningitides molecular characterization and whole-genome sequencing.

RESULTS

During 1998-2017, 1349 cases of IMD were notified in Israel (mean annual incidence rate 0.94/100,000). The peak incidence rates were observed in infants under 1 year of age (10.9/100,000). Case fatality rate was 9.7%. The majority of the N. meningitidis isolates were of serogroup B (67.9%). During 2007-2017, three clonal complexes (CC) 32, 41/44 and 23 (hyper-invasive clonal complexes) were the leading CC (61%). CC32 was the leading CC causing meningococcemia and mortality. In 2017, 35 isolates were tested for 4CMenB antigens variants; of the serogroup B isolates tested 46.7% showed a match to one or more antigens (fHbp or PorA:VR1), most were ST32 (CC32).

CONCLUSIONS

Preliminary analysis based on limited number of samples suggests that the 4CMenB coverage would be about half the strains; further research is necessary. Integration of clinical, epidemiological and laboratory data is essential to support decision-making on the introduction of the novel MENB vaccines in Israel.

Four-year antibody persistence and response to a booster dose of a pentavalent MenABCWY vaccine administered to healthy adolescents and young adults

This open-label, multicenter extension study (NCT02451514) assessed persistence of Neisseria meningitidis serogroups ABCWY antibodies 4 years after primary vaccination. Adolescents and young adults who previously received 2 doses of MenABCWY+OMV (Group III), 1 dose of MenACWY-CRM (Group VI), or newly-recruited vaccine-naïve participants (Group VII) were administered 1 (Group III) or 2 doses (Groups VI and VII) of MenABCWY+OMV, 1 month apart. Immunogenicity was assessed by human serum bactericidal assay (hSBA). Safety and reactogenicity were also evaluated. Percentages of participants with hSBA titers ≥8 (serogroups ACWY), ≥5 (serogroup B) and hSBA geometric mean titers (GMTs) were evaluated in all 129 enrolled participants (Group III: 33; Group VI: 46; Group VII: 50). Anti-ACWY antibody concentrations waned over 4 years post-vaccination, but remained above pre-vaccination concentrations. Similarly, levels of antibodies against serogroup B test strains also waned over 4 years post-vaccination, but remained above pre-vaccination concentrations for some strains. MenABCWY+OMV booster induced a robust anamnestic anti-ACWY response in Group III and VI and a good response against serogroup B test strains (≥82%) in Group III. In serogroup B-naïve participants (Groups VI and VII), anti-B responses to 2 doses of MenABCWY+OMV were less homogenous and lower than in Group III. MenABCWY+OMV was reactogenic, but well-tolerated. No safety concerns were identified. These findings indicate that although antibodies against N. meningitidis serogroups ABCWY waned over 4 years post-vaccination, exposure to a MenABCWY+OMV booster dose elicits an anamnestic response in adolescents previously exposed to the same or another multivalent meningococcal vaccine.

The unattainable criteria for new infant vaccines

BACKGROUND

In 2013, the US Advisory Committee on Immunization Practices (ACIP) opted against adding meningococcal vaccines to the infant schedule due to poor cost-effectiveness. This raises a policy question: if meningococcal disease is too rare to justify routine vaccination, are there other vaccine-preventable causes of US infant deaths that could be supported?

METHODS

We tabulated US infant deaths from 2009-2013 using the CDC WONDER database. These causes of death were then categorized into one of 3 categories: 1) vaccine-preventable using currently available interventions; 2) potentially vaccine-preventable within the next 10 years; and 3) not preventable.

RESULTS

From 19.8 million births (3.9 million/year), ∼122,000 infants died (0.62%). Of these, 181 (0.15% of all deaths) were preventable using currently available vaccines, while an additional 779 were categorized as potentially preventable in the next 10 y. By exclusion, 121,040 (99.2%) were judged 'not vaccine-preventable'. Meningococcal deaths contributed at most 0.03% of all infant deaths, but accounted for 17-34% of current vaccine-preventable deaths.

CONCLUSIONS

The low number of vaccine-preventable deaths in the US makes it increasingly difficult to justify the introduction of any new infant vaccines.

Meningococcal disease and vaccination: Knowledge and acceptability among adolescents in Italy

This study aimed to evaluate the knowledge, attitudes and practice about invasive meningococcal disease and the relative vaccine for adolescent in Italy. A cross-sectional study was conducted from March to May 2017 among a sample of 771 adolescents in the geographic area of Naples (Italy). A self-administered anonymous questionnaire was used to collect demographics, knowledge about meningitis and preventive measures, perceived risk for contracting meningitis, attitude towards the utility of meningococcal vaccine, and adolescents' willingness to receive a meningococcal vaccine. 85.2% of participants have heard about meningitis, 57.2% knew that adolescents are a susceptible population but only 30.3% knew that meningitis is transmitted by respiratory droplets. Moreover, 40.5% of adolescents knew that meningitis is a vaccine-preventable disease and that adolescents could be vaccinated. This knowledge was significantly greater among female participants, among those who talk with parents about vaccinations, among who have received information about vaccinations from physicians, among who have positive attitude towards the utility of information received on vaccinations and among who don't feel the need of additional information about meningitis. As regard the attitudes, 25.7% of adolescents thought that the vaccine was very useful. Males, adolescent aged 11-13 years, those who had the positive attitude towards the utility of information received about vaccinations and those who had received at least one vaccination in the last year were more likely to have this attitude. The our finding identifies the need to improve adolescents' knowledge about meningitis and its related vaccinations, through correct health education, in order to have a good acceptance of vaccination.

Impact of an Immunization Campaign to Control an Increased Incidence of Serogroup B Meningococcal Disease in One Region of Quebec, Canada

Background

Invasive meningococcal disease (IMD) incidence increased in Quebec, starting in 2003, and was caused by a serogroup B sequence type 269 clone. The Saguenay-Lac-Saint-Jean (SLSJ) region was particularly affected with a rate of 3.4 per 100000 person-years in 2006-2013. In May 2014, an immunization campaign was launched in SLSJ, using the 4-component protein-based meningococcal vaccine (MenB-4C). We aimed to evaluate the impact of the campaign 2 years after its initiation.

Methods

Immunization registry data and serogroup B invasive meningococcal disease (B-IMD) cases notified to public health authorities and confirmed by culture or polymerase chain reaction from July 1996 to December 2016 were analyzed, including a multivariate Poisson regression model of incidence rates.

Results

By the end of the campaign, 82% of the 59000 targeted SLSJ residents between 2 months and 20 years of age had been immunized. Following the initiation of the campaign, no B-IMD case occurred among vaccinees, whereas 2 cases were reported among unvaccinated adult SLSJ residents, and a third case in an unvaccinated child who had stayed in the region during the week prior to disease onset, in 2015. B-IMD incidence decreased in all other regions in the years 2015-2016 but sporadic cases continued to occur. A multivariate analysis showed a significant effect of the campaign in the SLSJ region (relative B-IMD risk: 0.22; P = .04).

Conclusions

Results suggest a high level of protection provided by MenB-4C following mass vaccination at regional level. This, along with reassuring safety data, supports the current recommendations for MenB-4C use for controlling outbreaks caused by clones covered by the vaccine.

Immunogenicity of a Booster Dose of Quadrivalent Meningococcal Conjugate Vaccine in Previously Immunized HIV-Infected Children and Youth

BACKGROUND

The US Advisory Committee on Immunization Practices recommends a booster dose of quadrivalent meningococcal conjugate vaccine (MCV4) after initial immunization for patients at high risk for meningococcal infection.

METHODS

The International Maternal Pediatric Adolescents AIDS Clinical Trials (IMPAACT) P1065 trial evaluated the use of MCV4 in human immunodeficiency virus (HIV)-infected children and youth. The final step of this trial was an open-label study of an MCV4 booster dose 3.5 years after primary MCV4 immunization. Antibody titers were evaluated at the time of the booster vaccine and 1, 4, and 24 weeks after the booster. Immunogenicity was measured by rabbit serum bactericidal antibody (rSBA) against each meningococcal serogroup. Immunologic memory was defined as either seroprotection (rSBA titer ≥1:128) or a ≥4-fold increase 1 week after the booster dose. Primary response was defined as either a ≥4-fold response or seropositivity 4 weeks after the booster in the absence of immunologic memory. Adverse events were assessed for 4 weeks after the booster dose.

RESULTS

Of 174 participants with serology results at entry and 1 and 4 weeks later, the percentage with protective antibody levels at entry varied according to serogroup, ranging from a low of 26% for serogroup C to a high of 68% for serogroup A. A memory response to at least 1 serogroup occurred in 98% of the participants: 93% each for serogroups A and Y, 88% for serogroup C, and 94% for serogroup W-135; 83% had a memory response to all 4 serogroups. Overall, rates of any memory or primary response were ≥90% for all serogroups. No serious adverse events were encountered.

CONCLUSIONS

A booster dose of MCV4 elicited a memory response in 88% to 94% of previously immunized HIV-infected participants depending on serogroup, including those who lacked a protective titer level for that serogroup before booster vaccination.

Breadth and Duration of Meningococcal Serum Bactericidal Activity in Health Care Workers and Microbiologists Immunized with the MenB-FHbp Vaccine

MenB-FHbp is a meningococcal serogroup B vaccine with two factor H binding protein (FHbp) antigens from subfamilies A and B. For licensure, efficacy was inferred from serum bactericidal antibody (SBA) responses to four reference strains. Only limited information is available on the breadth or duration of protective SBA responses to genetically diverse disease-causing strains. Seventeen health care or laboratory workers were immunized with two (n = 2) or three (n = 15) doses of MenB-FHbp at 0, 2, and 6 months. SBA levels were measured against 14 serogroup B case isolates, including 6 from U.S. college outbreaks and 2 from Quebec during hyperendemic disease. Compared with preimmunization titers, the proportion of subjects with ≥4-fold increases in SBA titer 1 month after 2 doses of vaccine ranged from 35% to 94% for six isolates with FHbp subfamily A and from 24% to 76% for eight isolates with subfamily B FHbp. The respective proportions with ≥4-fold titer increases at 1 month after dose 3 were 73% to 100% and 67% to 100%. At that time point, the proportion of subjects with titers of ≥1:4 (presumed sufficient for short-term protection) ranged from 93% to 100% for all 14 isolates. By 9 to 11 months after dose 3, 50% or fewer of the subjects with follow-up sera had protective titers of ≥1:4 for 4 of 9 isolates tested. Three doses of MenB-FHbp elicited short-term protective SBA responses to diverse disease-causing serogroup B strains. For some strains, serum titers declined to <1:4 by 9 to 11 months, which raises concerns about the duration of broad, long-term protection. (This study has been registered at ClinicalTrials.gov under registration no. NCT02569632.).

Serum Bactericidal Antibody Responses of Adults Immunized with the MenB-4C Vaccine against Genetically Diverse Serogroup B Meningococci

MenB-4C is a meningococcal vaccine for the prevention of serogroup B disease. The vaccine contains factor H binding protein (FHbp) and three other antigens that can elicit serum bactericidal antibodies (SBA). For vaccine licensure, efficacy was inferred from the SBA responses against three antigen-specific indicator strains. The relation between those results and broad protection against circulating genetically diverse strains is not known. Twenty adults were immunized with two doses of MenB-4C given 1 to 2 months apart. SBA activity against 3 reference strains and 15 serogroup B test strains (6 from college outbreaks) was measured. Compared to the preimmunization titers, 70%, 95%, and 95% of subjects had ≥4-fold increases in the titers of anti-PorA P1.4, anti-NadA, and anti-FHbp antibodies against the reference strains, respectively. In contrast, only 25 to 45% of the subjects had ≥4-fold increases in responses to 10 of the 15 test strains, including 8 that expressed one to three of the antigens in the vaccine. At 1 month, the majority of subjects with <4-fold titer increases had serum titers of ≥1:4, which are considered sufficient for protection. However, the titers against four strains declined to <1:4 by 4 to 6 months in one-third to greater than 50% of the subjects tested. Clinically relevant isolates are often more resistant to SBA than the indicator strains used to measure antigen-specific SBA. A working model is that the percentage of subjects with titers of ≥1:4 at 1 month postimmunization correlates with short-term protection against that strain, whereas the percentage of subjects with ≥4-fold titer increases represents a more robust response. (The protocol used at the Oxford Vaccine Group has been registered at ClinicalTrials.gov under registration no. NCT02398396.).

Immunogenicity of MenACWY-CRM in Korean Military Recruits: Influence of Tetanus-Diphtheria Toxoid Vaccination on the Vaccine Response to MenACWY-CRM

The quadrivalent meningococcal conjugate vaccine (MenACWY-CRM) has been introduced for military recruits in Korea since 2012. This study was performed to evaluate the immunogenicity of MenACWY-CRM in Korean military recruits. In addition, the influence of tetanus-diphtheria toxoids (Td) vaccination on the vaccine response to MenACWY-CRM was analyzed. A total of 75 military recruits were enrolled. Among them, 18 received a dose of MenACWY-CRM only (group 1), and 57 received Td three days before MenACWY-CRM immunization (group 2). The immunogenicity of MenACWY-CRM was compared between the two groups. The serum bactericidal activity with baby rabbit complement was measured before and three weeks after immunization against serogroups A, C, W-135, and Y. The geometric mean titers (GMTs) against four serogroups were significantly increased in both groups after immunization. Compared to group 2, group 1 exhibited significantly higher vaccine responses in several aspects: post-immune GMTs against serogroup A and C, seroresponse rates against serogroup A, and a fold increases of titers against serogroup A, C, and Y. MenACWY-CRM was immunogenic against all vaccine-serogroups in Korean military recruits. Vaccine response to MenACWY-CRM was influenced by Td administered three days earlier.

Active Surveillance for Adverse Events After a Mass Vaccination Campaign With a Group A Meningococcal Conjugate Vaccine (PsA-TT) in Mali

BACKGROUND

The monovalent meningococcal A conjugate vaccine (PsA-TT, MenAfriVac) was developed for use in the "meningitis belt" of sub-Saharan Africa. Mali was 1 of 3 countries selected for early introduction. As this is a new vaccine, postlicensure surveillance is particularly important to identify and characterize possible safety issues.

METHODS

The national vaccination campaign was phased from September 2010 to November 2011. We conducted postlicensure safety surveillance for PsA-TT in 40 government clinics from southern Mali serving approximately 400 000 people 1-29 years of age. We conducted analyses with individual-level data and population-level data, and we calculated rates of adverse events using the conditional exact test, a modified vaccine cohort risk interval method, and a modified self-controlled case series method for each outcome of interest, including 18 prespecified adverse events and 18 syndromic categories.

RESULTS

An increased rate of clinic visits for fever within 3 days after vaccination was found using multiple methods for all age groups. Although other signals were found with some methods, complete assessment of all other prespecified outcomes and syndromic categories did not reveal that PsA-TT was consistently associated with any other health problem.

CONCLUSIONS

No new safety concerns were identified in this study. These results are consistent with prelicensure data and other studies indicating that PsA-TT is safe. The approach presented could serve as a model for future active postlicensure vaccine safety monitoring associated with large-scale immunization campaigns in low-income countries.

Cost-effectiveness analysis of a multicomponent meningococcal serogroup B vaccine in hypothetic epidemic situation in a middle-income country

NmenB vaccine (4CMenB) is now available, but studies on the cost-effectiveness of vaccine introduction in a country outbreak situation are lacking. The aim of this study was to evaluate the cost-effectiveness of 4CMenB in the context of a hypothetical epidemic outbreak in Chile. We analyzed the direct and indirect costs of acute disease, sequelae and death for each case of meningococcal disease (MD) based on information obtained during the latest NmenB outbreak in Santiago, Chile, occurring between 1993-1999, with an incidence of 5.9/100,000 inhabitants and a mortality of 7.3%. We analyzed the cost of a mass vaccination campaign, considering one dose of 4CMenB for population between 12 months and 25 y of age and 3 doses for infants. Cost-effectiveness analysis was based on 80% and 92% 4CMenB immunogenicity for individual's bellow and over 12 months respectively. Sensitivity analysis was applied to different vaccine costs.

RESULTS

The total cost of the epidemic was USD $59,967,351, considering individual cost of each acute case (USD$2,685), sequelae (USD$2,374) and death (USD $408,086). In Chile, the 4CMenB mass vaccination strategy would avoid 215 cases, 61 sequelae, and 16 deaths per year. The strategy would be cost-effective at a vaccine dose cost ≤ of USD$18.

CONCLUSIONS

Implementation of a mass vaccination campaign to control a hypothetical NmenB outbreak in Chile would be cost-effective at a vaccine cost per dose ≤ of USD$18. This is the first report of a cost-effectiveness analysis for use of 4CMenB as a single intervention strategy to control an epidemic outbreak of NmenB.

Validation of the Vaccination Confidence Scale: A Brief Measure to Identify Parents at Risk for Refusing Adolescent Vaccines

OBJECTIVE

To validate a brief measure of vaccination confidence using a large, nationally representative sample of parents.

METHODS

We analyzed weighted data from 9018 parents who completed the 2010 National Immunization Survey-Teen, an annual, population-based telephone survey. Parents reported on the immunization history of a 13- to 17-year-old child in their households for vaccines including tetanus, diphtheria, and acellular pertussis (Tdap), meningococcal, and human papillomavirus vaccines. For each vaccine, separate logistic regression models assessed associations between parents' mean scores on the 8-item Vaccination Confidence Scale and vaccine refusal, vaccine delay, and vaccination status. We repeated analyses for the scale's 4-item short form.

RESULTS

One quarter of parents (24%) reported refusal of any vaccine, with refusal of specific vaccines ranging from 21% for human papillomavirus to 2% for Tdap. Using the full 8-item scale, vaccination confidence was negatively associated with measures of vaccine refusal and positively associated with measures of vaccination status. For example, refusal of any vaccine was more common among parents whose scale scores were medium (odds ratio, 2.08; 95% confidence interval, 1.75-2.47) or low (odds ratio, 4.61; 95% confidence interval, 3.51-6.05) versus high. For the 4-item short form, scores were also consistently associated with vaccine refusal and vaccination status. Vaccination confidence was inconsistently associated with vaccine delay.

CONCLUSIONS

The Vaccination Confidence Scale shows promise as a tool for identifying parents at risk for refusing adolescent vaccines. The scale's short form appears to offer comparable performance.

American Academy of Pediatrics Committee on Infectious Diseases. Updated recommendations on the use of meningococcal vaccines

Since the last policy statement from the American Academy of Pediatrics (AAP) concerning meningococcal vaccine was published in 2011, 2 meningococcal conjugate vaccines have been licensed for use in infants (Hib-MenCY-TT and MenACWY-CRM). The Centers for Disease Control and Prevention (CDC) has published new recommendations, "Prevention and Control of Meningococcal Disease: Recommendations of the Advisory Committee on Immunization Practices," which have been endorsed by the AAP. However, the CDC recommendations were published before licensure of MenACWY-CRM for infant use. This policy statement updates the AAP recommendations for use of meningococcal vaccines in children and adolescents. A more comprehensive review of background and technical information can be found in the CDC publication.

Genetic characteristics of Neisseria meningitidis serogroup B strains carried by adolescents living in Milan, Italy: implications for vaccine efficacy

Before a protein vaccine is introduced into a country, it is essential to evaluate its potential impact and estimate its benefits and costs. The aim of this study was to determine the genetic characteristics of Neisseria meningitidis B (NmB) in the pharyngeal secretions of 1375 healthy adolescents aged 13-19 y living in Milan, Italy, in September 2012, and the possible protection offered by the two currently available NmB protein vaccines. Ninety-one subjects were Nm carriers (6.6%), 29 (31.9%) of whom carried the NmB capsular gene. The 29 identified strains belonged to eight clonal complexes (CCs), the majority of which were in the ST-41/44/Lin.3 CC (n = 11; 37.9%). All of the identified strains harboured ƒHbp alleles representing a total of 15 sub-variants: the gene for NHBA protein was found in all but three of the studied strains (10.3%) with 13 identified sub-variants. There were 15 porA sub-types, seven of which were identified in just one CC. The findings of this study seem to suggest that both of the protein vaccines proposed for the prevention of invasive disease due to NmB (the 4-protein and the 2-protein products) have a composition that can evoke a theoretically effective antibody response against the meningococcal strains currently carried by adolescents living in Northern Italy. The genetic characteristics of NmB strains can be easily evaluated by means of molecular methods, the results of which can provide an albeit approximate estimate of the degree of protection theoretically provided by the available vaccines, and the possible future need to change their composition.

Safety and immunogenicity of quadrivalent meningococcal conjugate vaccine in 2- to 10-year-old human immunodeficiency virus-infected children

BACKGROUND

Human immunodeficiency virus (HIV)-infected children are at increased risk of meningococcal infection and poor response to quadrivalent meningococcal conjugate vaccine (MCV4), but MCV4 has not been studied in preadolescent HIV-infected children.

METHODS

The P1065 trial enrolled 2- to 10-year-old HIV-infected children with CD4 ≥ 25% to receive MCV4 at entry and at week 24. Rates of response (≥ 4-fold increase in rabbit serum bactericidal antibody) against each meningococcal serogroup (A, C, Y, W-135), geometric mean titers, and rates of seroprotection (rabbit serum bactericidal antibody titer ≥ 1:128) were determined from sera obtained at entry and weeks 4, 24, 28, and 72. Adverse events were assessed for 6 weeks after each MCV4 dose.

RESULTS

At entry, 47% of the 59 participants were male, 56% black, 31% Latino, median age was 6 years, 88% were receiving antiretroviral therapy, and 75% had viral load <400 copies/mL. There were no serious adverse events within 6 weeks after MCV4 doses; all vaccination reactions were mild. Response after a single MCV4 dose was high to serogroup A (92%) and W-135 (98%); responses improved after a second dose for serogroup C (43%-80%) (P < 0.0001) and Y (76%-84%) (P = 0.38). By week 72, seroprotection rates were 93%, 91%, 78%, and 46% for serogroups W-135, Y, A, and C, respectively.

CONCLUSIONS

Two doses of MCV4 were safe and immunogenic in 2- to 10-year-old HIV-infected children. The second dose increased the proportion of children who made a response to serogroup C. Seroprotection waned substantially for serogroups A and C within 1 year of last MCV4 dose.