researchers are working at a breakneck pace

to develop solutions that will allow economies

to reopen safely and permanently.

- Without an effective vaccine,

we won't be able to get this pandemic under control

and stop the devastation that it's currently causing

all around the globe.

- Vaccines can take an average

of 10 years to develop, according to a 2013 study,

but researchers and pharmaceutical companies

are hoping to bring their vaccine candidates

for the new coronavirus to market in 12 to 18 months.

Some are even talking about getting

Emergency Use Authorizations before the end of the year.

So what is making it possible

to expedite this process so dramatically?

There are several factors,

including prior knowledge of coronaviruses,

specifically SARS and MERS,

improvements in sequencing of viral genomes,

advancements in bioengineering technologies,

unprecedented government support and funding,

plus a shortened testing timeline.

Traditionally, after scientists develop a vaccine candidate,

they run it through a series of tests.

This starts in cells, and then transitions to animals,

usually beginning with mice

and eventually progressing to monkeys.

Testing only advances from one phase to the next

if it's proven to be safe and effective.

- At that stage, you would then likely perform

what we call a challenge study,

so that would be vaccinating an animal

then intentionally giving them the virus

and seeing the impact of your vaccine on that disease model

where, of course, you would hope to protect it.

- Then they'd use that data to get approval from regulators

like the FDA to begin human testing.

There are three stages of human trials,

each one testing more people than the last.

Approval is required for each stage.

Instead of this relay approach

where researchers wrap up each set of experiments

before embarking on the next round,

developers are now doing many tests in parallel.

- So we're not skipping steps, but we're doing things

at the same time, which of course costs a lot more

and is a lot more work than doing it one after the other,

and that's the key difference.

- The novel coronavirus was discovered and sequenced

less than six months ago.

Several candidates are already in phase one of human trials,

including those made by Inovio and Pfizer,

even as companies await results from animal studies.

Moderna recently started phase two.

Others are gearing up for phase two

before phase one wraps up.

- Our phase one trial will run for a year,

but we're not going to wait for that full year period

to have elapsed before we hopefully move on

to the next stage of efficacy testing.

- Because of the worry of COVID-19 being so devastating,

we are expediting those processes,

and this oughta concern, because we don't really know

all that much about immunity to this virus,

that we may be going too quickly,

but so that's the balance here.

- [Daniela] Vaccines work on a simple premise.

They trick the body into thinking a virus has infiltrated it

so the immune system kicks into action

and starts producing antibodies and other defenses

against parts of the virus.

In this case, scientists think their target

is the spike protein, which the coronavirus uses

to get into cells.

- It's been shown from SARS and MERS

that the spike protein is the major protein

on the outside of the virus of these coronaviruses

to which erase neutralizing antibodies,

and neutralizing antibodies is what you need

to fight the infection.

- So what would really end the pandemic

is when there's enough immunity in the population,

and either than immunity

comes from everybody getting infected

or it comes from a vaccine,

and it's a much gentler path for everybody to get a vaccine

than for everybody to get infected.

- [Daniela] This concept is known as herd immunity.

Dozens of companies and labs are trying various technologies

to develop vaccines that would get us there quickly.

Scientists say it's the largest,

most collaborative vaccine development effort

they've seen in their lifetimes.

They're testing four main strategies,

weakened viruses, proteins,

viral vectors, and genetic code vaccines.

Weakened or inactivated virus vaccines

are the most common.

That's your annual flu shot.

We have the most experience with these,

but they can also be costly

and time-consuming to mass-produce,

so in this case, they haven't been the preferred approach.

Protein-based vaccines

carry key parts of the virus into the body.

For coronavirus, that's the spike protein.

Sanofi and GlaxoSmithKline

are among dozens of developers taking this approach.

For viral vector vaccines,

scientists use an inactivated virus and stuff it

with the genetic code for the spike protein,

which our cells then use to turn out viral proteins.

The immune system then recognizes those as foreign.

Johnson & Johnson is developing this type of vaccine

for the coronavirus.

- [Gert] We use adenovirus vector,

and this adenovirus is a common cold virus

which normally doesn't cause any major disease,

just a common cold.

In the adenovirus, it becomes replication incompetent.

- [Daniela] In the fourth and final category

are genetic code vaccines.

These contain the instructions for the spike protein.

COVID vaccines being developed by Inovio,

Pfizer, and Moderna fall into this category.

These types of vaccines have never been approved

for humans before,

but they're generating a lot of excitement.

- The reason we're seeing them out in front is the speed.

- The speed in the manufacturing and the development?

- Yeah, really, both.

Proteins are more diverse.

They have all kinds of different shapes

and characteristics and so you have to play with a lot more

to actually get a protein-based vaccine made.

- [Daniela] Pfizer is running multiple candidates

through phase one trials in the U.S. and Germany

to cut down on development time.

- And even before we know whether the vaccine works or not,

we're starting to ramp up manufacturing capacity

so that we're ready to make it right away.

The key things you have to establish to develop a vaccine

are that it is safe, that it's effective,

and that every time you make it, it comes out the same,

so those key steps don't change whether you're going fast

or you're going slow.

- Changes in manufacturing can introduce unforeseen issues

that could make a vaccine dangerous.

That's what happened with the since-discontinued

polio vaccine decades ago.

Safety is a major concern,

because vaccines are given to healthy people,

so scientists have to ensure they don't affect things

like liver or heart function among other factors.

There are other issues as well.

Even if companies are able to come up with a vaccine

in less than two years, the vaccine research community

is concerned with how they'd be able

to produce and distribute it to everybody on the planet.

- So we are aiming to produce one billion dose

by the end of 2021, and some other companies

are committing to the same kind of scale,

either hundreds of millions or billions,

but still, it will not be enough for everyone.

- What is a big unknown is what the durability

of that protection is.

Is it going to be a year, two years,

or even maybe, unfortunately, six months or less,

because if it is measured in several months

instead of years, which is entirely conceivable

that that would be the case,

then we have a secondary problem.

How often do you need to boost somebody

to keep that level of immunity up?

- [Daniela] The final and perhaps most important hurdle

for coronavirus vaccine development will be human behavior.

- Are people gonna be accepting of this vaccine?

That's been such a huge problem in this country.

You know, if you have 50% of people

saying I'm not gonna take it under any condition,

then, of course, you've lost the whole battle.