Meningococcal B Vaccine and Meningococcal Carriage in Adolescents in Australia

Abstract

BACKGROUND The meningococcal group B vaccine 4CMenB is a new, recombinant protein-based vaccine that is licensed to protect against invasive group B meningococcal disease. However, its role in preventing transmission and, therefore, inducing population (herd) protection is uncertain. METHODS We used cluster randomization to assign, according to school, students in years 10 to 12 (age, 15 to 18 years) in South Australia to receive 4CMenB vaccination either at baseline (intervention) or at 12 months (control). The primary outcome was oropharyngeal carriage of disease-causing Neisseria meningitidis (group A, B, C, W, X, or Y) in students in years 10 and 11, as identified by polymerase-chain-reaction assays for PorA (encoding porin protein A) and N. meningitidis genogroups. Secondary outcomes included carriage prevalence and acquisition of all N. meningitidis and individual disease-causing genogroups. Risk factors for carriage were assessed at baseline. RESULTS A total of 237 schools participated. During April through June 2017, a total of 24,269 students in years 10 and 11 and 10,220 students in year 12 were enrolled. At 12 months, there was no difference in the prevalence of carriage of disease-causing N. meningitidis between the vaccination group (2.55%; 326 of 12,746) and the control group (2.52%; 291 of 11,523) (adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.80 to 1.31; P = 0.85). There were no significant differences in the secondary carriage outcomes. At baseline, the risk factors for carriage of disease-causing N. meningitidis included later year of schooling (adjusted odds ratio for year 12 vs. year 10, 2.75; 95% CI, 2.03 to 3.73), current upper respiratory tract infection (adjusted odds ratio, 1.35; 95% CI, 1.12 to 1.63), cigarette smoking (adjusted odds ratio, 1.91; 95% CI, 1.29 to 2.83), water-pipe smoking (adjusted odds ratio, 1.82; 95% CI, 1.30 to 2.54), attending pubs or clubs (adjusted odds ratio, 1.54; 95% CI, 1.28 to 1.86), and intimate kissing (adjusted odds ratio, 1.65; 95% CI, 1.33 to 2.05). No vaccine safety concerns were identified. CONCLUSIONS Among Australian adolescents, the 4CMenB vaccine had no discernible effect on the carriage of disease-causing meningococci, including group B. (Funded by GlaxoSmith-Kline; ClinicalTrials.gov number, NCT03089086.

Commensal Neisseria Are Shared between Sexual Partners: Implications for Gonococcal and Meningococcal Antimicrobial Resistance

“…The scarcity of nonpathogenic Neisseria within other bodily niches makes it unlikely that the skin, genital or anorectal site act as an intermediate in this transfer process. As already noted, different types of evidence suggest that pathogenic Neisseria species can be transmitted by kissing [6,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Our findings support to the idea that the genus Neisseria can be transmitted by kissing.…”

“…Concerns around the transmission of commensal Neisseria via kissing have emerged following increasing evidence of this mode of transmission for related bacteria. Several studies have found that kissing is a risk factor for meningococcal disease [9][10][11] or carriage [12][13][14][15] among students. Likewise, N. gonorrhoeae can be readily cultured from saliva [16][17][18], saliva use as a lubricant is a risk factor for rectal gonorrhea [19], kissing [20][21][22] as well as having a main partner with pharyngeal gonorrhea [23] may be risk factors for pharyngeal gonorrhea and a mathematical transmission model showed that oro-oral transmission is essential to generate the actual prevalence of gonorrhea among MSM [6].…”

One disease, two vaccines: challenges in prevention of meningococcal disease

“…The rapid rise of serogroups W and Y disease prompted all states and territories to fund MenACWY vaccination programs in 2017 and 2018 as an outbreak response . These programs varied but predominantly targeted adolescents aged 15–19 years, aiming to both directly prevent disease and to interrupt community transmission of meningococci through reduced acquisition of nasopharyngeal carriage, which is most prevalent in this age group . Some jurisdictions also implemented time‐limited vaccination programs covering select age groups, from infancy up to older adolescence, to control serogroup W outbreaks.…”

“…New data from the UK over 3 years estimate vaccine effectiveness against serogroup B IMD to be 52.7% (95% CI, −33.5 to 83.2) for a two‐dose primary schedule for infants, and 59.1% (95% CI, −31.1 to 87.2) for a two‐dose primary schedule followed by a booster dose at one year . However, Bexsero does not appear to have an impact on nasopharyngeal carriage of serogroup B, which implies that herd immunity (indirect protection in unvaccinated individuals) would be limited or absent despite population‐based vaccination . In addition, for both vaccines, protection against only around three‐quarters of all circulating MenB strains is predicted, based on in vitro assays …”

“…Low incidence rates have meant reliance on immunologic correlates of protection to predict vaccine impact (randomised placebo‐controlled efficacy studies are not feasible for such rare outcomes) and a limited number of post‐market vaccine effectiveness estimates. Other key uncertainties include the duration of protection and the magnitude of any herd protection effect, particularly for MenB vaccines, for which evidence is showing that there is no effect on nasopharyngeal meningococcal carriage . These uncertainties, together with the high cost of the MenB vaccines in particular, provide challenges for the value for money assessment necessary to underpin vaccine introduction into long term programs.…”