Vaccine maker Moderna started its final, phase 3 trial of a coronavirus vaccine in the United States Monday, and this is the stage that can’t be sped up, a top vaccine expert said.
Development of a coronavirus vaccine has been extremely fast so far, Dr. Paul Offit, the director of the Vaccine Education Center and professor of pediatrics at the Division of Infectious Diseases at Children’s Hospital of Philadelphia, told CNN.
“Typically vaccine development programs take 15 years on average. This vaccine development program is probably going to take a year and a half,” Offit said.
But the last part, the Phase 3 trial, will have to be taken more slowly, he said.
“The proof is in the pudding. The Phase 3 trial’s the pudding and now you’re going to test hopefully 10, 15 or 20 thousand people that will get this vaccine, 15,000 people that will get placebo and you’ll see to what extent this is really safe and you’ll see to what extent it’s effective.”
Data on whether the Moderna vaccine prevents infection should be available by the end of the year, and, if all goes well, it should be available for use by early 2021, although the vaccination process will take months.
“I’m willing to wait to see the data,” Offit said.
Mitigate risk: Offit said the Phase 3 trial helps to mitigate any sense of risk. “If you test it on 10,000 or 15,000 people and you find that it’s safe, you can say it doesn’t have an uncommon side-effect problem,” he said. But very rare side-effects won’t become obvious until after the vaccine is on the market, he said.
Pfizer and its partner BioNTech also said Monday they were about to start a phase 2/3 trial of their experimental coronavirus vaccine in the US.