The UK may be looking towards a future without parents fretting about their children catching meningitis, universities no longer having to put together contingency plans for outbreaks amongst amorous students, and the elderly not succumbing to this vicious disease. Reports last week of the successful preliminary clinical trial of a vaccine, shown to produce strong responses to the bacteria causing meningitis B, have raised hopes of eradicating meningitis from the UK and Europe.
The vaccine, MenB, was injected into 150 babies at 2, 4, 6 and 12 months of age, and triggered an immune response when tested against 3 strains of meningitis B. After the 4th dose, the immune response was 100%, 98% and 93%. When you hear these exciting and hopeful results, it’s easy to overlook the years of research that have led to this discovery when such results are published. Progress against this disease has depended heavily on animal studies.
Animals have helped us understand the disease, and test potential treatments and vaccines, so much so that the last decade has seen the UK vaccinated against Haemophilus influenzae type b (Hib vaccine), meningitis C, and a vaccine that offers immunity against the most common causes of pneumococcal meningitis.
Novartis, the company involved in producing the new MenB vaccine, continues to be the focus of a sustained campaign from anti-vivisection campaigners - in fact a whole week of action has been promised from the 26th May by one particular group. With such hope of getting rid of the disease, it is a wonder they don’t quieten down a little, and just let the scientists get on with their fight against one of the world’s deadliest killers.
Since describing meningococcal disease for the first time in 1805 during an outbreak in Geneva, we’ve come a long way. It took 82 years to identify Neisseria meningitidis as the cause, and about as long again to develop the first polysaccharide vaccines against the disease.
Until the vaccine was developed, much work was conducted trying to combat the disease. In the late 1800’s, Simon Flexner was researching cerebrospinal meningitis, using mice, guinea pigs and rabbits to investigate the disease. His research on monkeys led to a serum treatment for the disease by 1903. Further work developed a horse serum to treat the disease even more effectively. There’s a particularly interesting read available online from the 1908 NY Times, in which Flexner defends his work
Experimental work on chickens, and the passage of immunity from hen to chick embryo, helped in understanding the disease and contributed to vaccine development.
Research on bacteria causing pneumonia in mice resulted in a vaccine based on PRP, by coupling it to a protein. Following this, a vaccine against meningitis was developed using the same method. This vaccine produced a powerful response in mice and rabbits’ immune systems.
An upsurge in research occurred once the strains were genetically sequenced. Scientists genetically engineered a strain of meningitis B, from the C group, which did not cause the symptoms of the disease in mice. The injected animals were found to have developed antibodies not just against the engineered strain, but against A, B, and C groups.
The development and testing of the MenB vaccine also depended on testing the effects of the vaccine on mice.
Country specific vaccines against strains of type B Neisseria meningitidis have resulted in a dramatic drop in the number of cases seen in New Zealand, Norway and Cuba. With the UK’s immunization programme for Hib, pneumococcol and meningitis C, the B strain is currently the most common and deadly.
Meningitis B has proved to be more difficult to develop a vaccine for in this country as we have many different strains, and there have been concerns over inducing autoimmune antibodies. The MenB vaccine was developed through studying 85 strains of meningitis B, with the resulting product containing key antigens believed to be found in most meningitis B strains globally.
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