Feature

New meningitis vaccine in the pipeline

Dr Sanjit Bagchi

It is the most-feared disease in the Sub-Saharan African belt, which stretches from Gambia and Senegal on the Atlantic coast to Ethiopia and Somalia in East Africa - even though it kills fewer people than HIV, malaria or tuberculosis. To fight frequent epidemics of meningitis - which infects over 200,000 Africans every year either killing or maiming a third of those infected - public health experts have been looking for an ideal vaccine that confers long-term protection, that is suitable for all age groups and that breaks the transmission chain of the contagion in the population.

Above all, the vaccine has to be priced low enough so as to make it affordable for poorer countries. That dream vaccine to tame the dreaded infection is all set to turn into reality - thanks to a unique consortium
of drug developers at three corners of the globe.

To create the new meningitis vaccine - custom-made for the African meningitis belt - the Serum Institute of India has recently signed an agreement with the international Meningitis Vaccine Project (MVP), run by
the World Health Organisation (WHO) and the international charity PATH (Program for appropriate Technology in Health). The so-called conjugate meningitis vaccine A (Men A) is being developed at the Serum Institute's Lab in Pune, India, applying a new US Technology supplied by the US Food and Drug Administration. The raw materials - group A polysaccharides - are being supplied by SynCo Bio Partners based at Amsterdam in Netherlands. 

The joint venture will produce 25 millions doses of the vaccine every year at a cost as low as $ 0.40 cents per dose for the African meningitis belt.

"The agreement may offer a new paradigm for how vaccines or drugs are made for the poor countries," said US Food and Drug Administration scientist Carl E. Frasch in an email interview. "It's a concerted effort
(by the MVP) - the raw materials are produced at one place, technology to convert those materials into vaccine from another, and yet another place to manufacture the end product," he added.

Epidemics of meningitis have been occurring in the notorious 'meningitis belt' in Africa for more than a century. Such outbreaks surface roughly every eight to 12 years although their inter-epidemic period appears to be shrinking during the last two decades. The human toll of these epidemics can be enormous.

Between 1998 and 2002, African countries within the meningitis belt reported more than 224,000 new cases of meningococcal meningitis to the World Health Organization (WHO). However, cold statistics does not reflect the havoc actually associated with meningitis epidemics. The disease strikes suddenly and unless antibiotics are available and used quickly the death toll keeps rising. In addition, long-term effects are noticed in
one out of five cases of survivors who live with permanent disabilities such as hearing loss, mental retardation and paralysis.

Over the last couple of decades public health measures have focused on an approach based on early detection of the disease and mass vaccination of the population at risk with polysaccharide vaccines. However, these
vaccines have huge shortcomings in the African scenario - they have limited efficacy in young children, they don't produce long-lasting protection and do not confer herd immunity. In addition, the current epidemic control approach has to depend a lot on good surveillance and sound health infrastructure - both of which are not always available in the meningitis belt. Moreover, repeated vaccination (every three to five years) of the broad of the target group is not an easy task.

To address the limitations of the current public health strategy, expert panels at the MVP devised the idea of a conjugate meningococcal vaccine. "The Men A conjugate vaccine will help all people at risk from
epidemic Group A meningococcal disease prevalent in Africa," said Dr F. Marc LaForce, Director, Meningitis Vaccine Project in an email interview. The Men A vaccine will be used as preventive measure against the
epidemic. Which means it will be delivered through mass immunization targeting individuals from 1 to 29 years of age, as opposed to polysaccharide vaccines which have been used after the onset of an epidemic.

Conjugate vaccines have excellent track record against meningococcal disease. The first conjugate vaccine - a vaccine against meningitis caused by the Haemophilus influenzae bacterium (Hib) - was licensed in 1987 and
all countries (more than 35) that have adopted the Hib vaccine into their immunization programs have cut the incidence of invasive Hib disease to negligible levels. Similarly, the meningococcal C conjugate vaccine that was introduced in the United Kingdom in 1999 has drastically reduced the incidence of meningitis and carriage due to serogroup C meningococci. "Because conjugate vaccines can induce immunonologic memory it can result in a long-lasting protection (in contrast to polysaccharide vaccine),"
said Frasch. "It can also be used in young infants," he added.

Four years ago when WHO commissioned a panel of experts to assess the feasibility of the low-priced and high quality vaccine it was found that the shot was easier planned than actually produced. The intellectual property of the conjugation technology and production would come at such a hefty price that most countries in Africa won't be able to afford. No big pharmaceutical manufacturer was willing to make the shot at less than $ 1 per dose, and the target price was set at less than $0.50.

These seemingly insurmountable barriers forced the MVP to pursue a novel approach. In the new model the proposal was to source the conjugation process and basic components from a developed country, and then to
manufacture, test and store the final product in the developing country. With $ 70 million grant from the Bill & Melinda Gates Foundation MVP was able to forge a partnership between the FDA, SynCo Bio Partners and Serum Institute of India. "The Laboratory of Bacterial Polysaccharides of FDA transferred the conjugation technology to the Serum Institute of India," says Dr Frasch. The Dutch company supplied the vaccine grade
polysaccharide and the Serum Institute of India is scaling up its production to meet the target of 25 million doses of the vaccine annually.

"In order to assure a low-priced, high quality vaccine we had chosen this highly respected developing country manufacturer," said LaForce. The Serum Institute of India, based near Bombay, has an excellent track
record in vaccine production. It manufactures about 675 million doses of vaccine each day, and sends them to more than 137 countries across the world, through a contract with the WHO. "We are really proud to be
associated with this venture which will help people in the Sub-Saharan Africa," said Dr Suresh Jadhav, executive director of SII in an e-mail interview.

Jadhav, who is also president of the Developing Countries Vaccine Manufacturers' Network believes this a path-breaking initiative in making cheap vaccines for poor countries. "The success of Men A will indeed map
the way to new drugs and vaccines," said Frasch. "It will help basic research from the universities reach the poor."

More information:

Dr Sanjit Bagchi is a medical practitioner and medical journalist, based in India. Mr. Prasun Chaudhury, a senior science journalist from
India provided input into this article.

Photo credits:

Top photo: A mother sits by her sick daughter in a Ouagadougou clinic.
Children are the group most at risk of meningococcal disease in Africa. Photo © Rodrigue Barry, WHO/AFR

Bottom photo: Drought and dust storms are some of the factors associated with the development of epidemics in the meningitis belt.
Photo © Monique Berlier

Related websites:

Meningitis Vaccine Project

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