A vaccine is a biological preparation that improves immunity to a particular disease. It typically contains an agent that resembles a disease-causing micro organism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.
The agent stimulates the body’s immune system to recognise the agent as foreign, destroy it, and keep a record of it, so that the immune system can more easily recognise and destroy any of these micro organisms that it later encounters.
There are few immunisation issues more important than the appropriate storage and handling of vaccines. The success of efforts against vaccine-preventable diseases is attributable in part to proper storage and handling of vaccines. Vaccines exposed to temperatures outside the recommended ranges can have reduced potency and protection.
Storage and handling errors can cost a lot of money in wasted vaccine and revaccination. Vaccines must be stored properly from the time they are manufactured until they are administered.
A breakthrough has been recorded in science, as the first mass vaccination campaign conducted in Africa with a vaccine that does not require constant refrigeration succeeded in providing complete coverage while ensuring the vaccine stayed viable even in ambient temperatures up to 39°C (102.2°F), according to a study published online today in the journal Vaccine.
Conducted as part of a ten-day meningitis A vaccination campaign in Benin in November 2012, the study represents a breakthrough not only for the vaccine, MenAfriVac®, but potentially for increasing the efficiency, coverage, and affordability of other lifesaving vaccines as well, especially in remote, hard-to-reach areas where keeping the vaccine cold is difficult.
Researchers with Optimise, a now-completed collaboration between the World Health Organisation (WHO) and the global health non-profit PATH, cooperated with the government of Benin to implement the study.
For more than 100 years, sub-Saharan Africa has suffered from meningitis A epidemics that claim thousands of lives. In 1996 and 1997, an epidemic killed more than 25,000 people and sickened 250,000. Those who survive often suffer from deafness, epilepsy, loss of limb, and mental retardation.
Meningococcal disease is a leading cause of bacterial meningitis in teens. Meningitis is a dangerous inflammation of the lining of the brain and spinal cord that usually results from viruses or bacteria. Not all types of meningitis can be prevented with vaccines.
Fortunately, immunisation does protect against four types of meningococcal disease. The study found that this feat will reduce the workloads of health workers, who spend a lot of time maintaining the cold chain, and take vaccines to areas that are not powered by electricity.
According to WHO, over 20 million children are under vaccinated and remain at risk of being infected by vaccine-preventable diseases. This is due, in part, to the difficulties faced in the “last mile” for effectively getting the vaccine from a health centre to the vaccines.
“Finding solutions to reducing the cost and logistical challenges of reaching people living in remote areas would remove a major constraint to achieving universal coverage with vaccines beyond MenAfriVac. Indeed, a similar approach is being explored with the manufacturers of other vaccines, such as the yellow fever or the oral cholera vaccines,” said Michel Zaffran, coordinator of WHO’s expanded programme on immunisation and former director of Optimise, the WHO-PATH collaboration aimed at improving immunisation systems and technologies.
“The ability to use vaccines in a controlled temperature chain will certainly increase the cost-effectiveness of the Men-A strategy in settings where the cold chain infrastructure is fragile and will bring about significant savings on the operational costs of conducting a campaign in the meningitis belt countries,” said Patrick Lydon, a health economist at WHO and lead author of the study published in the WHO Bulletin.
Tailor-made to meet a major public health need in Africa, the MenAfriVac vaccine, which is manufactured by Serum Institute of India Limited, is already saving lives along Africa’s meningitis belt. Since 2010, more than 150 million people aged 1- to 29-years in 12 countries have received the vaccine with not a single group A meningitis case identified in the vaccinated populations.
By the end of the 2013 epidemic season, the number of meningitis cases in the belt was the lowest in ten years, a decrease attributed to the introduction of MenAfriVac. By 2016, the vaccine initiative aims to have reached more than 250 million people across the 26 countries in the meningitis belt.
By: Kemi Ajumobi
