Dr Tedros Adhanom Ghebreyesus
"I was born into a poor family. When I was seven, I lost my younger brother, probably to measles. I survived by chance, but it could have been me.
"For me, this position is about standing up for the rights of the poor.
"If I became director general, I would be very vocal on the issue of universal healthcare.
"We complain about emergencies or epidemics, worried it may come to our country. But if we ensure universal health coverage, we can resolve all of those issues.
"Inequity is a central challenge. The world has all the resources to save every life, as long as we believe every life is important.
"Those who have, do not care for the have-nots, and unless we confront that reality honestly, I don't think we will make progress."
Dr Sania Nishtar
"I was born and brought up in Peshawar on the Afghan border in Pakistan. I was raised in a progressive family. My father encouraged us to swim in the summer and play golf. I was a local golf champion by the time I was 16.
"When I was 15, my father passed away silently in his sleep - I think that was a turning point in my life.
"I trained as a cardiologist and I became very disillusioned with the disparity of care between the rich and the poor.
"My vision for this role centres on regaining the WHO's primacy, and ensuring that it has the world's trust as its lead health agency.
"Since the Ebola outbreak, the WHO has come under heavy criticism for its inability to... exercise stewardship during health emergencies.
"I want to make the organisation more accountable and transparent.
"I want it to focus on its core roles, rather than doing everything under the sun, in a half-baked way. I would lead the WHO very differently."
Dr David Nabarro
"My parents are both doctors, and probably because of their influence, I started working outside the UK.
"It was when I was working in Nepal in 1989, that I found how malnutrition and disease were most likely to come from households that faced particularly difficult circumstances in terms of income, the status of women and their access to sanitation and water.
"It seemed to me blindingly obvious that I had to work on the underlying determinants of health.
"My first priority if I become director general of the WHO, is to focus on universal health coverage - everybody being able to access healthcare when and where they need it.
"My second priority is to make sure people can be defended against outbreaks of disease.
"Thirdly, we are seeing increasing levels of diabetes, heart disease and mental ill-health. These kinds of non-communicable conditions could be prevented by better work across governments and society."