Long road ahead
There are more than 240 vaccine candidates worldwide in various stages of development as of Sept. 21, according to the Vaccine Centre at the London School of Hygiene and Tropical Medicine. Around 40 or so have advanced to clinical trials, a stage where the vaccines are tested on people – and where most vaccines wash out.
COVID-19 vaccine candidates
Drug companies and researchers have to jump through many hoops to prove that their vaccines are safe and effective on people. Historically, only 6% of vaccine candidates end up making it to market, often after a years- or decades-long process.
Here is how vaccine development usually works.
The global race for a COVID-19 vaccine is shattering the norms of speed and safety in drug and vaccine development. Through a White House initiative dubbed Operation Warp Speed, the United States is aiming to deliver 300 million doses of a COVID-19 vaccine by January 2021.
Typical development timeline
10-15
YEARS
Operation Warp Speed
~1YEAR
Typical development timeline
10-15
YEARS
Operation Warp Speed
~1YEAR
Typical development timeline
10-15
YEARS
Operation Warp Speed
~1YEAR
Typical development timeline
10-15
YEARS
Operation Warp Speed
~1YEAR
To save time, some developers are combining different phases of the clinical trials or running them at the same time, and some regulatory review is being fast-tracked. Others are working with regulators in multiple countries simultaneously, looking for the quickest path to market.
Experts have warned that the political pressure to speed the approval process at the potential expense of safety is leading to concerns.
Even once there is a working vaccine, that doesn’t mean the pandemic is over. Emerging evidence suggests that the body’s immune defence against COVID-19 may be short-lived, meaning vaccines may not be able to fully protect people in future waves of infection, scientists say.
“The over-reliance on a vaccine (to control the pandemic) is not wise,” said Stephen Griffin, a Leeds University associate professor of medicine.