Major advancements in medicine have led to a significant increase in average life expectancy, with vaccines being hailed as one of the most successful interventions to date.

This infographic via the Visual Capitalist explores how long it has historically taken to bring a vaccine to market during pandemics dating back to the 1900s, and what the process entails.

Some vaccines have been created and distributed in just months. Others have taken over 40 years to develop.

The vaccine for the H2N2 Asian flu was developed in less then 5 months in 1957. It took approximately 25 years to develop a vaccine for the Spanish Flu which killed between 40-50 million people. Last year the U.S. FDA approved the first Ebola vaccine — an effort that took 43 years since the discovery of the virus.

Even though there are no approved vaccines for other coronaviruses such as MERS and SARS, previous research into these diseases has helped identify solutions for COVID-19 using messenger RNA (mRNA) technology – in less than one year.

The diagram outlines the journey of a vaccine candidate, highlighting the 10 years and six stages involved in the process from start to finish.