A meningitis A vaccine (MenAfriVac) manufactured by Serum Institute of India, Pune was approved by WHO a few days ago for use in infants in sub-Saharan African populations. The vaccine will be introduced as part of the routine immunisation programme.
“In the four years since its introduction in Africa, MenAfriVac has had an immediate and dramatic impact in breaking the cycle of meningitis A epidemics,” a WHO release said. The vaccine has already been used in those aged 1-29 years. But with the WHO’s approval, the vaccine can be given to infants thereby “protecting million more children at risk of the deadly disease.” About 200,000 people suffer from meningitis every year in the region. The disease kills 20,000 to 25,000 people in the region every year.
“Like in the case of measles, not many meningitis cases are seen in children younger than one year,” said Dr. Suresh Jadhav, Executive Director of Serum Institute. “A mother, who has had meningitis, transmits the meningitis antibodies to newborns and these antibodies protect them for one year.” Every individual living in the meningitis belt (which stretches from Senegal in the west to Ethiopia in the east) gets infected with meningitis before the age of 29 years and hence mothers invariably carry antibodies against the disease.
The WHO has approved the use of a 5 microgram dose of the vaccine for children, which will be administered when they are nine months old. Immunisation at nine months will help achieve sustainable disease control following mass campaigns that target people belonging to the 1-29 age group.
Explaining the rationale for choosing to immunise at ninth month, Dr. Jadhav said: “It’s one opportunity to treat both measles and meningitis,” he said. Measles vaccination is also given to children at nine months of age.
A booster dose will be given when the child is 12-18 months old. According to Dr. Jadhav, the first meningitis dose will protect a child for five years and a booster dose will confer lifelong protection.
Though a single campaign has been carried out to cover a large population in 15 countries, those born after the campaign have not received the MenAfriVac vaccine and are hence vulnerable to meningitis infection. But with the introduction of the vaccine as part of the immunisation schedule, these children will also be protected.
The campaign mode will continue till 2017 in 3-4 countries per year. The current demand for the vaccine is 50-55 million. Once the campaign comes to an end, the demand will be directly proportional to the number of children born in the meningitis-endemic countries. “Twenty-five million children are born each year in these endemic countries. So 50 million doses will be the demand per year [as two doses are to be given to each child],” he said.
The Serum Institute had successfully made the vaccine heat stable so that it can remain outside the cold chain at temperatures less than 40 degree C for up to four days without the potency getting affected. Before it was made heat stable, the vaccine had to be kept in a cold chain at 2-8 degree C at all time. The vaccine was made heat stable by freeze-drying it.
The Serum Institute successfully demonstrated that the stability and potency of the meningitis vaccine remained intact even when exposed to higher temperature. The heat stable nature of the vaccine proved to be a game changer in meningitis control and made it possible to cover a large number of people through the campaign mode.
“It’s a great Indian success story,” Dr. Jacob John, a former virologist of the Christian Medical College (CMC), Vellore had earlier told this Correspondent. A study published in the WHO bulletin showed that using a CTC approach can reduce the cold chain related campaign costs by 50 per cent.