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MRC to conduct pneumococcal disease vaccine trial

Jan 25, 2011, 12:00 PM

The Medical Research Council will be conducting a vaccine trial on pneumococcal diseases at the Fajikunda Health Centre and surrounding communities.

The study is among others aimed at verifying safety and impact on carriage of the pneumococcus at the back of the throat in infants. It entails administering a total of three doses at 2, 3 and 4 months of age to about 1200 infants, and thereafter following them over a period of one year to monitor their well being, level of protection in the blood, and the rate of carriage of the pneumococcus at the back of the throat.

Funded by PATH (Program for Appropriate Technology in Health) organisation in Seattle, USA, the vaccine was first tested in Europe, after which GSK chose The Gambia as the first African country to test this vaccine.

Pneumococcal diseases are caused by the germ Streptococcus pneumoniae. There are about 94 different serotypes that is in circulation determined by the differences in the capsule covering the germ.

These germs are usually carried at the back of the throat in more than 90% of children under the age of one year in The Gambia, and cause disease when they enter the blood to any of the tissues mentioned above. They cause diseases that affect the ears, lungs (pneumonia), brain coverings (meningitis), and the entire blood (septicaemia).

These diseases, particularly pneumonia, are leading causes of childhood deaths, with highest impact in developing countries like The Gambia. Prevention by vaccine has been the most cost-effective approach towards reducing the suffering caused by the pneumococcal diseases. Pneumococcal conjugate vaccines (PCVs) have enormous potential to reduce the burden of pneumococcal diseases. Currently, three pneumococcal conjugate vaccines containing 7, 10 and 13 out of the 94 pneumococcal serotypes respectively are available for use in infants and toddlers. The number of serotypes protected by these vaccines was based on the most common types in the region. However, it has been noticed that other serotypes not contained in the vaccines have started causing severe diseases in areas where these vaccines have been implemented, a condition considered as replacement serotype phenomenon. Thus, despite improved serotype coverage with increase from 7 to 10 and 13 serotypes into the vaccines, global control of pneumococcal disease will be difficult to achieve by using serotype specific conjugate vaccines alone.

According to Dr. Martin Ota, principal investigator, one approach to this challenge is to formulate a vaccine that covers all the 94 types of the pneumococcus that cause diseases by using parts of the germ that are similar in all the serotypes.

"Interestingly, GSK Biologicals company in Belgium is the first to be developing such a vaccine, which uses some proteins that are found in all members of the pneumococcal family. The intention is to subsequently give this vaccine as a substitute to the PCV-7, which as 2, 3 and 4 months of age," he said.

Dr Martin, who has a huge team consisting of Drs. Aderonke Odutola, Ezra Ogundare, Muyiwa Owolabi and Bukky Idoko, plus several nurses, field workers, laboratory technicians, project managers and administrators added: "In order to provide amenities appropriate for such vaccine trials, GSK provided funds through MRC to construct a building that will house the project. MRC in their usual strive to improve health,  save lives and build capacity has also contributed in providing essential amenities to the HC including autoclave machine for sterilizing equipments for surgical operations and delivery, new toilets, computers etc, etc.

"Taken together, the HC and community have gained autoclave machine, computers, a new set of toilets, the services of clinicians, and will certainly inherit the building after MRC would have finished using it for their work.

Hopefully, if this vaccine is found to reduce the carriage of the pneumococcus at the back of the throat and to be well tolerated by the infants it might lead to the conduct of a bigger study to evaluate its impact on preventing the disease in The Gambia.

The Gambia already has the best immunization programme in Africa in terms of the number of vaccines administered and the proportion of children vaccinated."

While commending GSK and MRC for providing the funds for these activities/facilities, Dr Martin noted that should this vaccine being tested now be found useful, its addition into the existing vaccination schedule will further keep The Gambia at the top in Africa in terms of immunization. These, he added, only show the fruitfulness of the Gambia Government/MRC collaboration.