Why malaria vaccine is a world first

• Dr Cohen is the co-inventor and one of the original patent holders of RTS,S. As vice president of R&D for vaccines for emerging diseases and HIV at GlaxoSmithKline Biologicals, he manages early development of vaccines against some of the world’s leading infectious diseases, including HIV, TB and malaria.

This trial was designed not just by a couple of people sitting around a table but in consultation with many other experts in the field. The protocol of the trial was reviewed by regulatory agencies in the US and in Europe. It was also developed in consultation with the World Health Organisation. The sample size of 16,000 has been designed to give us power to demonstrate the efficacy of the vaccine and to generate sufficient data on safety.

The sample size is determined by the nature of the disease, so for some diseases the number could be higher or lower. However, the regulatory agencies have set a lower limit below which a vaccine will not be licensed, as the data would be deemed inadequate. 

Do you think it can be rolled out in Africa in spite of the financial and infrastructural problems, for example refrigeration?

We need to start working on finance and the public health infrastructure and delivery. Also, in most African countries’ Ministries of Health, immunisation and malaria prevention programmes are separate entities. They will need to come together to co-ordinate their efforts.