Good Question: How Are Vaccines Approved?
MINNEAPOLIS (WCCO) -- Experts say do not expect to see any possible protection from the Zika virus on the market until at least 2018.
At least five experimental vaccines to fight the Zika virus are in the works. So, how are vaccines approved?
"They have to go through an entire series of safety and efficacy studies," said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "First we have to prove that they're safe. Then we have to show that they really work."
All vaccines in the United States must be approved by the Food and Drug Administration. First, there is lab research, then testing on animals.
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"It typically is both private companies and public money," Osterholm said.
That is usually years before any vaccine is tested on humans.
"Some of these products, particularly some vaccines, may take $500 million to a billion dollars," he said. "And they could lose many more along the way. And so with that, it could take years."
There are three phases of human testing. In each phase, the sample size gets larger -- up to tens of thousands of people.
"We don't put vaccines into people unless, theoretically, they're going to work and they're going to be safe," Osterholm said. "You know, it's not like it's asking you to swallow gasoline and hope that it doesn't cause you a problem."
And then the testing continues years after FDA approval.
"Fast tracking means basically how they're moving it through to get to phase one or phase two," he said. "But remember, they fast-tracked the Ebola vaccine, too, and here we are two years later and we're still waiting and wanting," he said.
And a lot of vaccines get left on the table, like for the corona virus, SARS, MERS, Nipah and Ebola.
"I think we may have a Zika vaccine someday that's effective, but it's not going to happen soon," he said.
Dr. Osterholm says there are some serious safety concerns with the Zika vaccine because of the type of virus.
He also says by the time a vaccine is developed, the Zika virus might have infected and given immunity to so many people in South America that it will be hard to test a vaccine.
