World Health Organization has not announced plans to introduce RTS, S/AS01 in other regions at this stage, but does say the knowledge gathered through the pilot program will help their decision-making as they consider a potential wider use of the vaccine.
Mosquirix, which according to the World Health Organization, is the only vaccine developed against malaria that has reached the large-scale testing phase, will besides Kenya, be used in Ghana and Malawi from next year. While the vaccine has achieved some success in tightly controlled laboratory experiments, researchers are unsure whether this will translate into effective control in the real world, which is why they are only running the pilot in three countries to begin with.
Malawi has been selected for the world's ever first vaccine against malaria which will also involve Ghana and Kenya. Between 2000 and 2015, the number of people who died from this disease decreased by 62%.
Malaria remains one of biggest health challenges, infecting more than two hundred million individuals every year worldwide and leaving almost half a million dead.
In sub-Saharan Africa, which shoulders 90% of the global malaria burden, more than 663 million cases have been averted since 2001. The trial also documented a one-third reduction in the number of children requiring hospital treatment or blood transfusions.
It previously passed all of its clinical trials, including a phase three clinical trial between 2009 and 2014, and got approval for the large-scale pilot program in 2015.
"The slow progress in this field is astonishing, given that malaria has been around for millennia and has been a major force for human evolutionary selection, shaping the genetic profiles of African populations", Kathryn Maitland, professor of tropical pediatric infectious diseases at Imperial College London, wrote in The New England Journal of Medicine in December.
The Centers for Disease Control and Prevention said that about 1,500 cases of malaria are diagnosed in the USA annually, usually from travelers or immigrants returning from sub-Saharan Africa and South Asia.
Speaking on the development, Dr. Photini Sinnis, a deputy director at the Johns Hopkins Malaria Research Institute and professor at Johns Hopkins Bloomberg School of Public Health, said "this is great news, actually".
The vaccine doesn't provide flawless protection: In the most recent clinical trial that ended in 2015, it was only stopped about 30% of malaria cases in infants, and 40% in toddlers.
While a malaria vaccine would be an invaluable tool, other methods remain vital in preventing malaria. Those who are most vulnerable to the disease when infected include children under 5 years old, pregnant women, and non-immune travellers from malaria-free areas.
"There will be other vaccines and they'll be more efficient, but in the meantime, this will have a significant influence".
The injectable vaccine RTS, S developed by the British pharmaceutical giant GlaxoSmithKline (GSK) in partnership with the PATH Malaria Vaccine Initiative took decades of work and billions to develop.