The mumps vaccine is thought to hold the record for shortest turnaround: four years. When researcher Maurice Hillleman’s daughter contracted the virus in 1963, he took a throat swab to his lab. A vaccine based on the “Jeryl Lynn” strain was approved in 1967.

Some newer vaccines have been decades in the making. The chickenpox vaccine, approved in 1995, took 28 years to develop. The 2006 HPV vaccine took 15. Testing for safety and effectiveness, manufacturing millions of doses and regulatory review all take time.

Researchers have been trying to create an HIV vaccine for nearly 35 years. While medications have been developed to help people manage HIV and AIDS, there is still no vaccine.

Today, there are over 100 Covid-19 vaccines in development around the world. At least eight are being tested on people, including one with encouraging early results from the drug maker Moderna. Will the crisis create a record breaking vaccine? Time will tell.

To learn about a milestone in vaccine development from the ’50s, check out our story on Jonas Salk and polio.

This article was adapted from a Twitter thread created with support from a Brown Institute for Media Innovation grant recognizing the need for accurate information about the Covid-19 virus. Learn something new from history: Subscribe to our newsletter, and follow us on Twitter @RetroReport.