We're in the business of helping people feel better and live healthier lives. Figuring out how to do it is just the first step.

Before we can develop a new medicine or vaccine, we need to understand the basics. How exactly does the disease or condition work? And which mechanisms have the potential to help prevent or treat it?

It takes a long time to identify a potential new treatment. Teams of scientists might screen thousands of compounds to identify a promising lead. That compound will then need to be refined, optimised and tested in clinical trials with regulatory approval required at every step of development.

As part of the initial screening process, our researchers look at many different considerations, including:

• Is the safety profile appropriate for use in patients with a particular disease?
• Does the compound potentially have the desired effect?
• What is the best means of administration?
• Could it potentially provide improvement over existing options?

Drug discovery is often an expensive and high-risk undertaking. We spend billions of dollars each year to discover and develop medicines and vaccines that can help people around the world. But thanks to the talent and tenacity of our scientists – combined with the scientific and technological advances of the past decade – we are entering an exciting period of research at MSD as we continue to seek new and even better ways to improve health.

For more information about the drug discovery and development process, visit http://www.phrma.org/innovation