Prof Helen Marshall, University of Adelaide, Australia
Professor Marshall is a medical researcher with specialist training in child health, public health and vaccinology having completed a Bachelor of Medicine and Surgery, Doctorate of Medicine, Master in Public Health and Diploma in Child Health at the University of Adelaide and completed the international Advanced Vaccinology Course at the Pasteur Merieux Institute, France.
She holds the position Professor in Vaccinology in the Adelaide Medical School and is the Deputy Director, Clinical and Translational Research of the Robinson Research Institute at the University of Adelaide, Senior Medical Practitioner and Medical Director of VIRTU, the Vaccinology and Immunology Research Trials Unit, in the Department of Paediatrics at the Women’s and Children’s Hospital. She has been awarded two National Health and Medical Research Council, Research Fellowships in 2011 and 2015. In recognition of her research leadership she was awarded the South Australia Science Award for Excellence in Research for the Public Good in 2010 and a national Public Health Association of Australia Fellowship in 2013.
Professor Marshall’s research program aims to address urgent priorities in infectious disease prevention to reduce the burden of disease from serious infections in infants and children. Her main interests include meningococcal, human papillomavirus, influenza and pertussis infections and their prevention by immunisation.
She is the Principal Investigator on the South Australian Meningococcal B vaccine carriage study ”B Part of It” and has completed numerous clinical trials on the safety and immunogenicity of meningococcal vaccines. Her research program includes clinical trials in investigational vaccines, infectious and social epidemiology and public health. She has published over 120 peer-reviewed papers in high quality general medicine and specialist journals across diverse disciplines. She has been awarded 10 National Health and Medical Research Council grants and received funding from the Australian Research Council, Government, Foundation and Industry grants totalling >$25 million.
In South Australia (SA), which has the highest rate of meningococcal disease nationally, serogroup B predominates, causing >80% of cases. No funded MenB vaccine program exists due to insufficient data on vaccine effectiveness and evidence of herd immunity. Carriage prevalence of Neisseria meningitidis in Australian adolescents is unknown.
The SA MenB vaccine herd immunity study “B Part of It” aims to estimate the difference in carriage prevalence of all N. meningitidis serogroups causing disease, in school students receiving two doses of 4CMenB compared to unvaccinated students at 12 months post-vaccination. A pilot study in first year university students was conducted to determine carriage prevalence and identify risk factors associated with carriage.
Materials and Methods
In the longitudinal carriage study of university students a posterior pharyngeal swab was collected at baseline and 3 months later to determine PCR porA positivity and genogroups.
From April-June 2017, senior school students (years 10-12) were recruited to the cluster RCT. All SA schools (metropolitan, rural, remote, very remote) were invited to participate and randomised to Group A intervention (4CMenB) or Group B control (no vaccine). Posterior pharyngeal swabs were obtained from all students at the first school visit with Group A students receiving 2 doses of 4CMenB, 2 months apart. At 12 months post dose 1 all students are re-swabbed. The study is implemented through the school immunisation program with immunisation providers trained in a standardised posterior pharyngeal swab technique. Swabs are placed in transport medium (STGG) and sent to a central state pathology collection centre. DNA extraction and porA real time PCR analysis performed. Positive PCR samples are cultured for Neisseria species on selective agar. In an add-on study a 1 ml saliva sample was collected from each participant, added to STGG and underwent real time PCR.
Pilot university carriage study
421 university students were enrolled and 258 completed both day 0 and 3-4 months swabs. Only 1.9% of students smoked cigarettes and 3.3% used a water-pipe. Baseline and 3 month carriage prevalence was 6.2%; serogroup Y (2.8%, 2.3%), serogroup B (1.7%, 1.2%), serogroup W (0.7%, 0%). Baseline carriage of those attending a second visit was 3.9% compared to 9.8% in those only attending the first visit. 32% of those who only attended the first visit compared to 13% of those attending both visits, visited pubs/clubs ≥ 2 nights per week (p<0.001). In an add-on study in which saliva was collected at visit 2 (n=238), carriage prevalence was 5.5%; serogroup B (1.3%), serogroup W (0.4%), serogroup Y (2.1%).
Cluster RCT in school students
Over 95% of schools participated (n=237) with consent forms distributed to 58,000 students. 37,410 students consented with 34,461 participating at the first visit including 17,912 (52%) females. The majority were from metropolitan schools (74%), followed by rural (23%), remote (2.4%) and very remote (0.6%). Students will return in April 2018 for a repeat swab and vaccination of Group B students.
Carriage prevalence is low in first year university students in South Australia, likely due to very low rates of smoking and social behaviour.
Funding (source): GlaxoSmithKline Biologicals SA. Add-on saliva study funded by Women’s and Children’s Health Network, South Australia