Meningococcal disease epidemiology in Australia 10 years after implementation of a national conjugate meningococcal C immunization programme

Abstract

Australia implemented conjugate meningococcal C immunization in 2003 with a single scheduled dose at age 12 months and catch-up for individuals aged 2-19 years. Several countries have recently added one or more booster doses to their programmes to maintain disease control. Australian disease surveillance and vaccine coverage data were used to assess longer term vaccine coverage and impact on invasive serogroup C disease incidence and mortality, and review vaccine failures. Coverage was 93% in 1-year-olds and 70% for catch-up cohorts. In 10 years, after adjusting for changes in diagnostic practices, population invasive serogroup C incidence declined 96% (95% confidence interval 94-98) to 0·4 and 0·6 cases/million in vaccinated and unvaccinated cohorts, respectively. Only three serogroup C deaths occurred in 2010-2012 vs. 68 in 2000-2002. Four (<1/million doses) confirmed vaccine failures were identified in 10 years with no increasing trend. Despite published evidence of waning antibody over time, an ongoing single dose of meningococcal C conjugate vaccine in the second year of life following widespread catch-up has resulted in near elimination of serogroup C disease in all age groups without evidence of vaccine failures in the first decade since introduction. Concurrently, serogroup B incidence declined independently by 55%.

Epidemiology of invasive meningococcal B disease in Australia, 1999–2015: priority populations for vaccination

“…Since the meningococcal C conjugate vaccines (MenCCV) were added to the National Immunisation Program in 2003, the incidence of group C meningococcal disease in Australia has remained very low among both vaccinated and unvaccinated people. This finding of indirect protection (herd immunity) is consistent with observations of reduced carriage prevalence among vaccinated adolescents in the United Kingdom 7 , 8 . The recent development of two MenB vaccines that afford protection against multiple strains provides new opportunities for preventing group B disease.…”

“…First, the peak incidence of MenC disease was in late adolescence, rather than in infancy and early childhood; second, case fatality rates for adolescent patients were higher for MenC disease; third, there was no disparity between Indigenous Australians and others in the incidence of MenC 17 . This epidemiological profile led to selecting the schedule of a single dose of MenCCV at age 12 months or later (initial or catch‐up doses); together with an extensive catch‐up campaign for children and adolescents, this markedly reduced MenC incidence to its current low levels through a combination of direct and indirect (herd immunity) effects 7 , 8 , 18 …”

Vaccine‐preventable child deaths in New South Wales from 2005 to 2014: How much is preventable?

“…The meningococcal C deaths in our study occurred between 2005 and 2007, with most children eligible for meningococcal C vaccine catch‐up programmes under the NIP. Although meningococcal C vaccination coverage has been high (93%), coverage is lower in catch‐up cohorts (70%) . Most meningococcal deaths in our study were due to meningococcal B disease; most occurred before the meningococcal B vaccine (which is now recommended but not funded under the NIP for young children, particularly those aged <24 months, adolescents aged 15–19 years and those with specific medical conditions) became available in 2014.…”

“…We identified 12 deaths due to meningococcal disease over the 10‐year study period, substantially less than the 26 deaths identified in NSW in children less than 15 years between 2000 and 2007 . There has been a dramatic decline in meningococcal C disease since the introduction of the meningococcal C immunisation programme in 2003 . The meningococcal C deaths in our study occurred between 2005 and 2007, with most children eligible for meningococcal C vaccine catch‐up programmes under the NIP.…”

Procalcitonin and C‐reactive protein may help to detect invasive bacterial infections in children who have fever without source

“…Craig et al. reported a lower prevalence of SBIs (7.2%) and IBIs (0.4%) from data collected between 2004 and 2006, which could be explained by the high level of vaccine coverage and herd immunity in Australia . However, despite suboptimal vaccination coverage in France, IBIs have decreased in recent years following steady advances in the pneumococcal conjugate and the decrease in group C invasive meningococcal disease .…”