When Will a Covid-19 Vaccine Be Ready?

In March, National Institute of Allergy and Infectious Diseases director Anthony Fauci told US senators, “It will take at least a year and a half to have a vaccine we can use.” That might seem like an eternity for public health officials staring down a probable pandemic. But if true, it would actually set a record. Most vaccines take between five and 15 years to come to market, says Jon Andrus, an adjunct professor of global vaccinology and vaccine policy at the Milken Institute of Public Health at George Washington University.

The reason it usually takes so long comes down to a combination of factors. The first is getting a candidate vaccine that’s ready to test. This part of the vaccine development process, known as discovery, used to take years of careful benchtop biology. Scientists had to isolate and grow viruses in the lab. But now, with genetic sequencing, new protein-visualizing microscopes, and other technology advances, it’s possible to skip that step. Arriving at a vaccine candidate can sometimes be done in weeks.

All those advances, though, can’t speed up the time it takes to meticulously monitor how well these candidate vaccines work in people. Clinical trials, a prerequisite for bringing a vaccine to market, are the real bottleneck. Each happens in three stages. Phase 1 involves just a few dozen healthy volunteers, and is meant to evaluate whether the vaccine is safe. That takes about three months. If the healthy volunteers don’t suffer any adverse effects, it’s on to Phase 2. This time, several hundred people will get the shot, ideally in an area experiencing a Covid-19 outbreak, so scientists can gather data on how well it spurs the production of antibodies and fends off the disease for these trial subjects. That’s another six to eight months. If everything still looks good, Phase 3 is to recruit a few thousand people in an outbreak zone and repeat the experiment. That’s another six to eight months—if you don’t have any problems recruiting patients or with your vaccine supply. Then a regulatory agency, like the US Food and Drug Administration, has to review all the data before making a decision about whether to approve the vaccine. That can take months to a year.

If you’ve been doing the math, this means that, since vaccine candidates started being developed in January, a version approved for public use won’t be available until the end of summer 2021, at the earliest. And that’s if nothing goes wrong. “Constricting the whole timeline of going from concept to a product that can be distributed into a year or two is really a herculean endeavor,” Andrus says.

Only a handful of companies have vaccine candidates ready to move into human testing, but more than 30 have joined the race. Even if one of these companies does pull off the Thirteenth Labor, they’re left with a novel product that still requires manufacturing and distribution. “The first question we should be asking is: Does this producer have the capacity to scale it up?” asks Andrus. If not, a limited supply will force public health officials to make tough decisions about rationing out a vaccine.

Source: www.wired.com/story/everything-you-need-to-know-about-coronavirus-vaccines/