World-first study targets Meningococcal B
Professor Helen Marshall About 45,000 adolescents are being immunised against Meningococcal B disease in South Australia in a statewide study led by the University of Adelaide.
The initiative could lead to vaccination programs throughout Australia and overseas to stamp out the crippling disease which can result in limb amputations, brain injuries and death.
There are six strains of the meningococcus bacteria but in Australia, over past decades, most cases have involved either the B or C strains. More recently nationally there has been an increase in the W strain. While there is a national immunisation program in place to vaccinate against meningococcal C disease, the cost-effectiveness of a program for the B strain is still under review.
The new statewide study led by the University’s Robinson Research Institute, known as B Part of It, could hold the key.
The program is being run in partnership with SA Health and has been approved by the Women’s and Children’s Health Network Human Research Ethics Committee.
It involves providing the licensed Meningococcal B vaccine free to about 45,000 adolescents enrolled in Years 10, 11 and 12 in schools across South Australia. This will help determine the impact of immunising large community groups against the disease.
Professor Helen Marshall, Deputy Director of the Robinson Research Institute and Director of the Vaccinology and Immunology Research Trials Unit at the Women’s and Children’s Hospital, says the study is believed to be the first of its kind and the rest of the world is eagerly awaiting the outcome.
“The size of the study, and the fact that many countries will use the data to determine whether they will implement a MenB vaccine, makes it an exciting study to be part of,” she says.
Teenage children have been chosen because they have a high rate of carriage and transmission of the bug that causes meningococcal infection.
The meningococcus bug is carried in the throat of adolescents with up to 20-25 per cent carrying the bacteria.
“Most of the bugs are the harmless strains but some of them are hypervirulent,” says Helen.
“What is difficult for us to know, is who is carrying which strain type, therefore having an immunisation program where you can reduce the carriage overall should reduce the risk of transmitting those hypervirulent strains.
What the study also aims to prove is whether the MenB vaccine has a herd immunity benefit similar to what was seen with the MenC vaccine.
“Herd immunity is when a significant portion of a population is immunised against a disease, preventing its transmission from one person to another and protecting those who are not immune,” says Helen.
“I think a lot of people understand that if we get vaccinated we are protecting ourselves, but actually the herd immunity impact is a much more powerful protective effect, as we saw with the MenC vaccine.
“It is given to one-year-olds but has actually reduced the disease in all age groups. The C strain has almost disappeared in Australia and this can only be happening because we are reducing the transmission of the bug.”
This is one of the key pieces of information that Australia’s Pharmaceutical Benefits Advisory Committee (PBAC) is seeking to help determine if the MenB vaccine is suitable for an immunisation program.
“If a herd immunity benefit is proven, it would mean that the protection would be extended to others in the community by significantly reducing the transmission of the bug and therefore occurrence of the disease. This would make it a more cost-effective solution,” says Helen.
The researchers have been encouraged by the response of the South Australian community in support of the study.
“It really has been a whole-of-state approach. We are working closely with local government to deliver the program through immunisation nurses who deliver immunisations in schools and who will do the study throat swabs and the vaccinations,” she says.
“We have a very strong partnership with SA Health and SA Pathology is doing all of the microbiology work.
“Working with the schools has been great and the Department of Education and Child Development, Independent Schools Association and Catholic Education have been very encouraging and supportive of schools’ participation.
“We have 236 schools that have agreed to participate – we’ve even had a couple of schools ring up just to make sure that they are still on our list.”
Find out more about the B Part of It study.
Professor Helen Marshall
Professor Helen Marshall is an alumna and a medical clinician researcher with specialist training in paediatrics, vaccinology and public health. She 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 the international Advanced Vaccinology Course at the Pasteur Merieux Institute, France.
Her passion in children’s health and vaccinology stems from time spent during her medical degree on a paediatric ward in a hospital in Western Samoa where she saw firsthand the devastating effects of infectious diseases in a country low on medical resources. This inspired her to move into paediatrics, which led to an opportunity to work on clinical trials with vaccines to protect children against serious infections.
Story by Kelly Brown
Photo by Russell Millard