The MeNZB vaccine developed to control New Zealand’s meningococcal B epidemic in 2004-5 has helped researchers to create another, more advanced vaccine targeting more variants of the bacterial pathogen.
Although the MeNZB was ‘tailor-made’ for New Zealand, some of the bacterial components targeted by the vaccine have now been incorporated in to a new vaccine which aims to provide immunity to all variants of meningococcal B serotype.
A clinical trial of the vaccine, published this week in leading medical journal The Lancet, has reported success in providing sustained immunity to meningococcal B.
The new broader 4CMenB vaccine targets several different parts of the bacterium, including, a “PorA-containing outer membrane vesicle preparation previously used to control a serogroup B clonal outbreak in New Zealand.”
Meningococcal B causes much of the remaining meningococcal disease burden across high-income countries (where it is common) and also regions such as South America (where it is the most prevalent strain).
The clinical trial, based in Chile, shows that, after two or three doses, blood samples from 99-100% of recipients indicating protection from meningococcal B infection. The B strain of the bacteria has been the most difficult to control globally due to regional variability and a lack of broadly acting vaccines to date.
The authors of the study conclude:
“This pivotal study shows that two doses of the novel 4MenCB vaccine separated by 1, 2, or 6 months provide a potentially protective immune response in almost 100% of adolescents irrespective of previous antibody status. Actual levels of protection will depend on geographical variation of strains…Further study is needed to provide information about the immunogenicity and tolerability of 4CMenB in various age groups, including infants, who bear the largest disease burden worldwide.”
Our friends at the UK Science Media Centre collected the following comments.
Kate Rowland, Head of development at Meningitis UK said:
“Meningitis Group B is the major cause of meningococcal disease in the UK, causing about 2,000 cases per year (mainly in the under-fives followed by adolescents).
“The UK is a hot spot for Meningitis B with one of the highest incidence rates of the disease in the world.
“Scientists have been trying to develop a vaccine against Meningitis B for years but it has been very challenging as its capsule is similar to the structure of human nerve cells and the bacteria is clever; mutating and adapting. Trying to get a vaccine to induce protection in infants/toddlers, amongst whom most of the disease occurs, has been very problematic.”
Dr Myron Christodoulides, Senior Lecturer in Molecular Microbiology at the University of Southampton and chair of Meningitis UK’s Scientific Medical Panel, said:
“Previous studies have shown that 4CMenB has the potential to provide significant protection when administered to infants. This new study shows that the vaccine could also be highly protective in the adolescent age group.
“However, there are still a number of important questions to be answered such as how many strains it will protect against, how long the protection will last and whether it will stop the bacteria from being passed on to others, providing indirect protection to those not vaccinated.”
Press (and other Fairfax papers): Kiwi role in advance on new meningitis vaccine
New Zealand Herald: Vaccine hope for deadly meningitis strain
Radio New Zealand: New vaccine developed against meningitis strain