In the six weeks since the first locally transmitted Zika virus was diagnosed in the United States, 64 individuals in the Miami area have been confirmed to have caught the virus locally, and they are just a fraction of the more than 600 people in the state who now have Zika.

The mosquito-borne Zika virus is officially in the US, and questions over how quickly it will spread, how it can be stopped, and what risks it poses are adding pressure to the race to quickly find and implement a vaccine.

Launching a Global Vaccine Quest

Zika poses the most risk to pregnant women since it causes a birth defect known as microcephaly, in which babies are born with smaller heads and brains, as well as other brain damage. The CDC is also investigating a link between Zika and a nervous system disease called Guillain-Barré Syndrome grown adults.

With such deadly consequences of the disease, the World Health Organization was spurred to declare Zika a public health emergency seven months ago, and launched a global race to find a vaccine for the growing epidemic.

The WHO’s declaration set off a chain of global events involving major government agencies, billions of dollars, an array of pharmaceutical companies and biotech firms, and hundreds of researchers across the world, all racing to help create a vaccine to stop the disease from spread. But regardless of the urgency, we’re still years away from having a viable vaccine, a host of experts tell Global Citizen.

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Dan Epstein, a WHO spokesman, the Zika outbreak is completely unprecedented.

“In a sense, it’s totally unknown. We’ve never before had a mosquito-transmitted disease that causes congenital birth defects transmitted vertically from mother to womb,” he told Global Citizen in an interview.

Almost immediately after Zika being designated a world health crisis, the WHO and UNICEF gathered together experts in vaccines and virus-borne diseases, including epidemiologists, vaccine regulators, and pharmaceutical companies, to create a “target product profile,” which describes what would be needed in a vaccine so that everyone would be working toward a common goal, Epstein said. This allowed groups to go off and begin their own research into a vaccine while the WHO shared information and coordination about their efforts.

There are now 30 groups who are all pursuing different possible vaccines, including pharmaceutical companies, biotech firms, academic researchers, and government institutions, mainly in the US and Brazil, the epicenter of the current epidemic, which diagnosed nearly 8,000 cases in the month of March during the height of the outbreak.

And while the WHO doesn’t have regulatory power to direct any of their efforts, the organization helps groups avoid duplication or unnecessary work, partly by tracking the research products in a public Google Doc, allowing the researchers and the public to see the different projects’ progress in real time.

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The Leaders

In June, the first potential vaccine, developed by Inovio Pharmaceuticals, got the green light to start testing in humans. Two months later, the National Institutes of Health announced that a DNA-based vaccine created by the National Institute of Allergy and Infectious Diseases that had been successful in animal tests would begin testing in 80 volunteers.

Two other groups, including researchers at Harvard who have published two papers showing efficacy in mice and primates, and the pharmaceutical company Sanofi, will look to begin human trials in the coming months. If the initial tests prove that the drugs are safe, they can begin testing for effectiveness, likely next year, according to Bloomberg.

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While those vaccines are leading the way for human testing, other companies and researchers are pursuing alternative vaccines in case those prove ineffective or unsafe.

This month, the US Department of Health and Human Services (HSS) awarded $8.2 million in funding to the pharmaceutical company Moderna Therapeutics to help develop and test its RNA-based vaccine. The money was reallocated from the country’s Ebola-earmarked funds.

The Timeline

If the world is still facing a Zika emergency outbreak in the next year or two, an emergency vaccine could become available by 2018, according to Anthony Fauci, director of NIAID

But a vaccine could also take much longer. Epstein, of the WHO, pointed out that the search for a dengue vaccine has taken 20 years, and the results are still modest: There’s one vaccine that is “sort of successful” for one or two strains of dengue. He doesn’t think a Zika vaccine will take 20 years, but it could be three to five years before there’s a vaccine.

Some experts are already predicting that in the time it takes to find a vaccine and successfully bring it to market, the need will almost have evaporated.

Justin Lessler, an epidemiologist at Johns Hopkins Bloomberg School of Public Health, is one of several researchers who have published studies showing that the Zika outbreak peaked earlier this year.

“It’s likely that it’s peaked in most locations in the Americas,” Lessler told Global Citizen. “We’re pretty confident that in the Americas over the next two to three years, the case counts will go down significantly and will stay low for some period, from four to five years to a couple of decades after that. That’s the way the epidemic dynamics look when a disease invades a population.”

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John Heinrichs, associate vice president of vaccine development at Sanofi, told Global Citizen he expects the virus to continue to spread in the southeastern United States throughout the fall, particularly because of hurricane season and flooding, leading to wet conditions favorable to mosquitos.

But Lessler thinks that’s unlikely, noting that the mosquitos that spread Zika likely won’t travel beyond south Florida and South Texas.

“That’s not to say it’s impossible — this virus is new and has surprised us elsewhere, but based on what we’ve seen so far it’s unlikely it will spread outside of that range,” Lessler said.

There is still some question about whether there will be outbreaks in Asia and Africa or whether those populations already have some immunity. Under the current epidemic, he said, there probably won’t be a vaccine out in time  to have a large effect.

But that doesn’t mean researchers can take their time, Lessler said.

“In a sense we are under a very tight clock,” he said, noting that they need to test and perfect the vaccine while Zika is still an epidemic, before it becomes dormant in the population.

“You want the vaccine to be in place before the next epidemic occurs,” Lessler said. “The next epidemic, whenever it does come back, there’s a good chance it’ll be an explosive epidemic again.”

The Money

When the HHS allocated its final $8 million to Moderna this month, it also announced that it was out of money, and had awarded all $85 million that it had taken from the Ebola research fund to put toward Zika.

President Barack Obama asked Congress in February to allocate $1.9 billion in emergency funding to Zika research, but as of this week, Congress has failed to agree on a funding bill to award any new money to finding a vaccine or treatment for Zika.

Senate Majority Leader Mitch McConnell said on Sept. 12 that he hoped to advance the legislation allocating the funds in the following days.

"Basically, we are out of money and we need Congress to act," CDC Director Dr. Tom Frieden said on Aug. 30

The need for Congressional action is particularly important as the major, well-funded pharmaceutical companies have decided not to put their resources into finding a Zika virus in the same way they did for the Ebola outbreak two years ago. Then, companies like Merck and Johnson & Johnson quickly engaged in research toward a vaccine. This time, the companies said they would look into vaccines, but did not rush to get involved.

“This is not seen as a commercial market, at least for the time being,” Marie-Paule Kieny, an assistant director-general at the WHO, told Bloomberg about the major pharmaceutical firms’ reluctance to get involved.

Read More: The Zika Budget Battle

Michael Diamond, a Zika researcher at Washington University in St. Louis, Missouri, said that the groups currently trying to find a vaccine are making “phenomenal progress,” but that they need the financial support to continue it.

“In terms of generating a budget that is actually useful for this field, if they don’t begin to resolve the issues, there are groups that are going to have to drop off,” Diamond told Global Citizen.

Heinrichs and Lessler both stressed the importance of shaping public policy going forward so that the US and other countries are able to respond more quickly and commit more funding toward other outbreaks.

“A lot of what we do in vaccine development is in response to these crises, and it’s really needed for there to be a system in place where there is sustained funding that allows companies to respond proactively rather than after we see them,” Heinrichs said.

Lessler said that the public health sector needs to be better prepared to respond to crises as they come up, partially by having money set aside that can be easily reallocated for research.

“We should be not having to have a debate in Congress when we need academic funding and not having to be stealing from the money to prevent the next Ebola outbreak to chase the current Zika outbreak,” he said.

“The epidemic process moves much quicker than the political process,” Lessler said.