The WHO is the lead agency in health in the United Nations system, and clearly we have very important functions to play.

For a pandemic of moderate severity, this is one of our greatest challenges: helping people to understand when they do not need to worry, and when they do need to seek urgent care.

Everyone needs to remember that Ebola was not a worst-case scenario. Preparedness for the future means preparedness for a very severe disease that spreads via the airborne route or can be transmitted during the incubation period, before an infected person shows telltale signs of illness.

Some experts say we are moving back to the pre-antibiotic era. No. This will be a post-antibiotic era. In terms of new replacement antibiotics, the pipeline is virtually dry. A post-antibiotic era means, in effect, an end to modern medicine as we know it. Things as common as strep throat or a child's scratched knee could once again kill.

When WHO works with the private sector, the Organization takes all possible measures to ensure its work to develop policy and guidelines is protected from industry influence.

New diseases like SARS and bird flu cause anxiety in the community. People get worried, some to the extent that it even affects their health. You feel very sad, and yet you must carry on and maintain your cool in very trying and difficult moments. You have to tough it out.

HIV AIDS is a disease with stigma. And we have learned with experience, not just with HIV AIDS but with other diseases, countries for many reasons are sometimes hesitant to admit they have a problem.