What do you mean "ethics dictates?" We define ethics and they generally reflect the current culture, ethics aren't universal and can't dictate anything.
The scientific method, though, would dictate that a cohort size should be large enough to show a high probability of safety and efficacy, assuming that is what is being tested. It would also dictate that a control group would be needed to compare against the test group.
I totally understand the ethical concerns of potentially allowing children to be harmed while part of a control group, but when the test is being done specifically because there is currently no treatment the only change is that they would pick a group of untreated children that are a valid control group for the study. Either way those children wouldn't be treated and there really isn't an ethical issue to deal with.
Having a control group in a life saving intervention study is a major ethical dilemma that isn't as simple as they would die if not in the study.. There's a lot of information about study ethics and it is more complex a subject than you imply.
Is it in this case though? The study, and the related article, states that there is currently no approved treatment for the population. What is the harm in following a control group that would otherwise still go untreated?
The claim still holds then that there are no approved treatments for malaria in this age range. If we were already treating patients off book, and that were the reason we couldn't have a control group, then there is no real reason to do the study at all.
The scientific method, though, would dictate that a cohort size should be large enough to show a high probability of safety and efficacy, assuming that is what is being tested. It would also dictate that a control group would be needed to compare against the test group.
I totally understand the ethical concerns of potentially allowing children to be harmed while part of a control group, but when the test is being done specifically because there is currently no treatment the only change is that they would pick a group of untreated children that are a valid control group for the study. Either way those children wouldn't be treated and there really isn't an ethical issue to deal with.