Drug regulators in agreement on coronavirus vaccine trials, FDA official says
Marks’ comments signal the kind of evidence vaccine developers will need to gain regulatory clearance, and suggest health authorities will be aligned on the level of proof required.
Typically, vaccines take many years, or even more than a decade, to win approval based on their ability to prevent infections or disease. Now, however, governments aim to speed development to limit illness and death from COVID-19, as well as the economic disruption caused by public health measures meant to curb infections.
Top government health officials have said they believe a vaccine can be made available within 12 to 18 months, and the White House’s ‘Operation Warp Speed’ is pushing for one by the end of this year, or early next. Despite the urgency, Marks cautioned that the FDA and its international counterparts will still want large trials.
“I don’t think there’s going to be a lot of arguing about the size of the trials, because I think we all understand that if you’re going to be thinking about treating hundreds of millions of people with a vaccine, you’re going to want to have safety datasets to start that are reasonably sized,” he said during a panel discussion on vaccine development.
Marks added that, in those trials, companies will need to “follow people closely, because you may not get another chance” to evaluate its safety as effectively.
In order to achieve herd immunity, he added, vaccines will need to be highly potent and public health authorities will need to persuade people skeptical of vaccines to receive injections.
“If 30% or 40% of the population will not take this vaccine, even if the vaccine effectiveness is 70% to 80%, we will not be in a position to have herd immunity,” Marks said.
The diversity of vaccine approaches — the Milken Institute counts 161 vaccines in preclinical and clinical development — gives a good chance for such a vaccine to emerge, or perhaps multiple.
In an earlier discussion at the BIO meeting, National Institute of Allergy and Infectious Diseases director Anthony Fauci predicted there will be “more than one winner” in the coronavirus vaccine race, emphasizing several will be needed to provide the world with billions of doses.
“I’m almost certain that we’re going to have multiple candidates that make it to the goal line, get approved and get widely used,” he said. The first Phase 3 trial of a coronavirus vaccine should start “in the beginning of the summer in July,” he added.
AstraZeneca and Moderna both aim to begin late-stage tests of their respective vaccine candidates around that time.
Varied approaches also hedge against the failure of one technology, or one approach, like targeting the coronavirus’ characteristic spike, or “S,” protein.
“We’re all betting on the same S protein,” Gary Nabel, Sanofi’s chief scientific officer, said during the vaccines panel. “It’s good to have some diversity. I like the fact that there is an inactivated cold virus vaccine, because that provides an alternative in case one of these should fail.”