In the present study the compositional analysis of the amino acids released by the acidic hydrolysis of the vaccine antigens was approached as an alternative to the dye-binding methods, for improvement of the quality control. In particular, the Analytical Quality by Design principles were undertaken in optimizing the hydrolysis conditions of the antigens to be applied prior to the quantitation by UHPLC-UV. Bexsero was used as a case study; it is a recombinant meningococcal B vaccine and one of its critical quality attributes is the content of the three core protein antigens, namely Neisseria Heparin Binding Antigen, factor H binding protein and Neisseria adhesin A, in the final formulation. Conventionally, the proteins quantitation is carried out by dye-binding assays. Analytical Target Profile was defined as the accurate determination of amounts of the Bexsero antigens. The Critical Method Parameters were chosen by means of the cause-effect matrix. A Face Centered Design was used to select the experiments to investigate the process and finally a Method Operable Design Region with a risk of failure of 5% was defined. The selected working point for routine use was: hydrolysis time, 17 hrs; temperature, 112 °C; 6 M HCl volume, 300 µl; antioxidant 90% phenol volume, 5 µl.

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BACKGROUND: Acute cerebellar ataxia (ACA) and acute cerebellitis represent disorders characterized by a para-infectious, post-infectious, or post-vaccination cerebellar inflammation. They are relatively common neurologic disorders among children, and may follow infections, or, more rarely, vaccinations. Few cases are instead described among infants. Although the immunization with meningococcal group B (MenB) vaccine has been associated with some neurological side effects, suspected ACA has been reported only once in the literature.
METHODS: we describe a 7-month-old female that presented ACA within 24 h from the MenB second dose vaccination. Extensive laboratory studies and magnetic resonance imaging excluded other causes. We then conducted an extended review of other vaccine related cases reported in the literature, focusing on the clinical characteristics of ACA and finding that ataxia and cerebellitis of para- or post-infectious cause are very rarely described in the first year of life. We collected 20 articles published in the last 30 years, including an amount of 1663 patients (1-24 years) with ACA.
CONCLUSIONS: a very small number of suspected post-vaccinal ataxias has been described in recent years, compared to other causes, and vaccination remains an unquestionable medical need. Further research is needed to clarify the complex pathogenesis of this disorder and its eventual link with vaccinations.

BackgroundMeningococcus (Neisseria meningitidis) is the causative bacteria of invasive meningococcal disease (IMD), a major cause of meningitis and sepsis. In 2015-16, an outbreak caused by serogroup C meningococci (MenC), belonging to the hyperinvasive strain ST-11(cc-11), resulted in 62 IMD cases in the region of Tuscany, Italy.AimWe aimed to estimate the key outbreak parameters and assess the impact of interventions used in the outbreak response.MethodsWe developed a susceptible-carrier-susceptible individual-based model of MenC transmission, accounting for transmission in households, schools, discos/clubs and the general community, which was informed by detailed data on the 2015-16 outbreak (derived from epidemiological investigations) and on the implemented control measures.ResultsThe outbreak reproduction number (Re) was 1.35 (95% prediction interval: 1.13-1.47) and the IMD probability was 4.6 for every 1,000 new MenC carriage episodes (95% confidence interval: 1.8-12.2). The interventions, i.e. chemoprophylaxis and vaccination of close contacts of IMD cases as well as age-targeted vaccination, were effective in reducing Re and ending the outbreak. Case-based interventions (including ring vaccination) alone would have been insufficient to achieve outbreak control. The definition of age groups to prioritise vaccination had a critical impact on the effectiveness and efficiency of control measures.ConclusionsOur findings suggest that there are no effective alternatives to widespread reactive vaccination during outbreaks of highly transmissible MenC strains. Age-targeted campaigns can increase the effectiveness of vaccination campaigns. These results can be instrumental to define effective guidelines for the control of future meningococcal outbreaks caused by hypervirulent strains.

Introduction. Invasive meningococcal disease (IMD) caused by Neisseria meningitidis may show temporal and geographical changes in both the epidemiology and the characteristics of the strains involved.Gap statement. A study that examined invasive N. meningitidis causing IMD in Atlantic Canada from 2009 to 2013 was published in 2014. Data from subsequent years have not been described.Aim. This study examined the molecular epidemiology of IMD in four Atlantic Provinces of Canada as well as potential serogroup B (MenB) vaccine coverage.Methods. Individual IMD case isolates recovered from 2014 to 2020 were analysed for serotype and serosubtype antigens as well as by whole-genome sequencing (WGS) for prediction of potential MenB vaccine coverage.Results. Of the 56 IMD isolates, 42, 8, 5 and 1 were MenB, serogroup Y, serogroup W (MenW) and serogroup C, respectively. Geographical differences in the distribution of MenB clones revealed concentration of sequence type (ST)-269 clonal complex (cc) and ST-60 cc in Newfoundland and Labrador, while ST-41/44 cc (particularly ST-154) was predominantly found in New Brunswick and Nova Scotia. Core genome multi-locus sequence typing (cgMLST) also separated the New Brunswick and Nova Scotia ST-154 isolates into two clusters, with differences in their nhba and penA alleles. Furthermore, cgMLST also separated the ST-269 cc isolates in Atlantic Canada into the ST-1611 and the ST-269/ST-8924 clusters, with the latter showing high similarity to the ST-269 that first emerged in the Province of Quebec. Genetic Meningococcal Antigen Typing System showed that 54.8 % of MenB were predicted to be covered by the MenB vaccine Bexsero, with a further 38.1 % potentially covered by virtue of the presence of genes that encoded factor H-binding protein variant 1 proteins. Meningococcal deduced vaccine antigen reactivity predicted from WGS data showed that 95.3 % of MenB were covered by Trumenba. Four cases of IMD due to MenW ST-11 cc were also identified, with the first case found in 2018.Conclusions. This study provided evidence concerning the dynamics of N. meningitidis strains causing IMD in Atlantic Canada, with both geographical and temporal differences found. MenB vaccine appeared to provide good coverage of MenB IMD, especially towards the predominant strain of ST-154.

We assessed the vaccination effectiveness (VE) of multicomponent meningococcal serogroup B (4CMenB) vaccine against gonorrhea among people living with HIV (PLWH) with a previous diagnosis of sexually transmitted infection.
Unmatched case-control study on men who have sex with men living with HIV, in care at San Raffaele Scientific Institute, Milan, Italy, with gonorrhea, syphilis, chlamydia, or anal human papillomavirus between July 2016 (beginning of 4CMenB vaccination) and February 2021 (date of freezing). For the analysis, cases were people with ≥1 gonorrhea infection since July 2016, and controls were people with ≥1 syphilis, chlamydia, or anal human papillomavirus infection since July 2016. Logistic regression was used to provide the estimate of 4CMenB VE against gonorrhea.
Included people living with HIV were 1051 (103 cases, 948 controls); 349 of 1051 (33%) received 2 doses of 4CMenB vaccination. The median follow-up was 3.8 years (2.1-4.3 years). The unadjusted estimate for VE against gonorrhea was 42% (95% confidence interval, 6%-64%; P = 0.027). Logistic regression showed that VE against gonorrhea remained significant (44%; 95% confidence interval, 9%-65%; P = 0.020) after adjusting for some factors that might have a potential influence on VE or those with significant unbalanced distributions between cases and controls at univariable analysis.
4CMenB vaccination is associated with a lower risk of gonorrhea in the setting of men who have sex with men living with HIV with a previous sexually transmitted infection.

Here we present as case study how re-randomization tests were performed in two randomized, controlled clinical trials as sensitivity analyses, as recommended by the United States Food and Drug Administration in the context of adaptive randomization. This was done to confirm primary conclusions on immunological noninferiority of an investigational new fully liquid presentation of a quadrivalent cross-reacting material conjugate meningococcal vaccine (MenACWY-CRM), over its licensed lyophilized/liquid presentation. In two phase 2b studies (Study #1: NCT03652610; Study #2: NCT03433482), noninferiority of the fully liquid presentation of MenACWY-CRM to the licensed presentation was assessed and demonstrated for immune responses against meningococcal serogroup A (MenA), the only vaccine component modified from lyophilized to liquid in the new presentation. The original vaccine assignment algorithm, with a minimization procedure accounting for center or center within age strata, was used to re-randomize participants belonging to the fully liquid and licensed vaccine groups while keeping antibody responses, covariates and entry order as observed. Test statistics under re-randomization were generated according to the ANCOVA model used in the primary analysis. To confirm immunological noninferiority following re-randomization, the corresponding p-values had to be <0.025. For both studies and all primary objective evaluations, the re-randomization p-values were well below 0.025 (0.0004 for Study #1; 0.0001 for the two co-primary endpoints in Study #2). Re-randomization tests performed to comply with a regulatory request confirmed the primary conclusions of immunological noninferiority for the MenA of the fully liquid compared to the licensed vaccine presentation.

A programme of vaccination with the four-component serogroup B meningococcal (4CMenB) vaccine was introduced in South Australia for infants and children aged 0-3 years on Oct 1, 2018, and for senior school students in school years 10 and 11 (aged 15-16 years) and young adults aged 17-20 years on Feb 1, 2019. We aimed to evaluate vaccine effectiveness and impact on serogroup B meningococcal disease and gonorrhoea 2 years after implementation of the programme.
We did a cohort and case-control study among those targeted by the South Australia 4CMenB vaccination programme. We obtained disease notification data from SA Health, Government of South Australia, and vaccine coverage data from the South Australian records of the Australian Immunisation Register. Vaccine effectiveness was estimated as the reduction in the odds of infection using the screening and case-control methods. Vaccine impact was estimated as incidence rate ratios (IRRs), obtained by comparing case numbers in each year following the start of the vaccination programme with cases in the equivalent age cohort during the pre-vaccination programme years. We used Poisson or negative binomial models, as appropriate, with adjustment for changes in the incidence of serogroup B meningococcal disease in age cohorts not eligible for vaccination through the state programme.
4CMenB vaccine coverage 2 years after introduction of the childhood vaccination programme was 94·9% (33 357 of 35 144 eligible individuals) for one dose, 91·4% (26 443 of 28 922) for two doses, and 79·4% (15 440 of 19 436) for three doses in infants. The one-dose (77·1%, 16 422 of 21 305) and two-dose (69·0%, 14 704 of 21 305) coverage was highest in adolescents born in 2003 (approximately year 10 students). 2 years after implementation of the childhood vaccination programme, incidence of serogroup B meningococcal disease was significantly reduced compared with before programme implementation in infants aged 12 weeks to 11 months (adjusted IRR [aIRR] 0·40 [95% CI 0·23-0·69], p=0·0011), but not in those aged 1 year (0·79 [0·16-3·87], p=0·77), 2 years (0·75 [0·18-3·14], p=0·70), or 4 years (3·00 [0·47-18·79], p=0·24). aIRRs were not calculable in those aged 3 or 5 years because of no cases occurring after programme implementation. aIRR for serogroup B meningococcal disease was 0·27 (0·06-1·16, p=0·078) in adolescents aged 15-18 years 2 years after implementation of the adolescent and young adult programme, and 1·20 (0·70-2·06, p=0·51) in those aged 19-21 years in the first year. Two-dose vaccine effectiveness against serogroup B meningococcal disease was estimated to be 94·2% (95% CI 36·6-99·5) using the screening method and 94·7% (40·3-99·5) using the case-control method in children, and 100% in adolescents and young adults (no cases reported after implementation). Estimated two-dose vaccine effectiveness against gonorrhoea in adolescents and young adults was 32·7% (8·3-50·6) based on the case-control method using age-matched individuals with chlamydia infection as controls.
4CMenB vaccine shows sustained effectiveness against serogroup B meningococcal disease 2 years after introduction in infants and adolescents, and moderate effectiveness against gonorrhoea in adolescents. The high vaccine effectiveness against serogroup B meningococcal disease is likely due to high coverage in the target age groups and close antigenic match between the 4CMenB vaccine and the disease-associated serogroup B meningococcal strains circulating in South Australia. COVID-19-related physical distancing policies might have contributed to further declines in serogroup B meningococcal disease cases during the programme\'s second year.
SA Health, Government of South Australia.

Multiplicity issues are increasingly common in vaccine clinical studies. Common causes include multi-valent combinations/co-administrations requiring separate evaluation of each antigen; numerous efficacy endpoints; requests from regulatory authorities for inclusion of specific powered endpoints into registration studies; interim analyses to support early decision-making. In a Phase III study to evaluate safety and immunogenicity of the 4-component Neisseria meningitidis serogroup B vaccine (4CMenB) when co-administered with 13-valent pneumococcal conjugate vaccine (PCV13) to healthy infants, a total of 49 statistical hypotheses were identified for the primary objectives as requested by the health authority. We designed a sequential testing strategy with visualization using a graphical gatekeeping procedure.
The 49 immunogenicity objectives related to evaluation of the sufficiency of the 4CMenB immune response; and demonstration of non-inferiority of PCV13 and 4CMenB when co-administered versus administration alone. We used a graphical shortcut display for closed families assuming that the multiple testing procedure is consonant and hypotheses that are rejected by a closed testing procedure are also rejected within the graphical short-cut. The 49 hypotheses were grouped into 10 families and distributed over 4 sequential steps following the clinical and statistical logical relationships agreed with the clinical team. Test decisions within the first 8 families will be made based on p-values with alpha propagation to subsequent families according to the tree structure.
This tailored strategy allowed evaluation of all 49 statistical hypotheses individually, and more efficiently. The method avoided a rigid all-or-nothing approach whereby all endpoints fail if one or more null hypotheses cannot be rejected. Clinical input and agreement are critical for designing an efficient and fit-for-purpose strategy. Our experience could encourage more application of such strategies in increasingly complex clinical trials.

Serogroup Y Neisseria meningitidis (NmY) is rare in China, and only serogroup A and C meningococcal polysaccharide vaccines (MPVs) are included in the national vaccination schedule. We describe a case of fulminant meningococcemia caused by NmY, which occurred in a pediatric patient (2 years old) for the first time in China, confirmed by culture. Although the boy was treated in time, the dry gangrene in his toes and fingers left him with severe sequelae. An NmY isolate was cultured from the blood of the patient, and showed decreased susceptibility to penicillin (minimum inhibitory concentration of 0.125 μg/ml), with sequence type (ST) 1655 assigned to clonal complex (cc) 23. Genomic analysis showed it was clustered with isolates from Italy, UK, Finland, and South Africa, sharing designation of Y:P1.5-1,10-1:F4-1:ST-1655(cc23). The emergence of NmY invasive meningococcal disease cases challenges local immunization strategy and warrants wider usage of MPV-ACYW if there is sustained circulation of NmY.