0:00:06.674,0:00:08.534
When a new pathogen emerges,

0:00:08.534,0:00:12.204
our bodies and healthcare systems[br]are left vulnerable.

0:00:12.204,0:00:16.144
In times like these,[br]there’s an urgent need for a vaccine

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to create widespread immunity[br]with minimal loss of life.

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So how quickly can we develop vaccines[br]when we need them most?

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Vaccine development can generally [br]be split into three phases.

0:00:27.728,0:00:32.071
In exploratory research, scientists [br]experiment with different approaches

0:00:32.071,0:00:35.371
to find safe and replicable [br]vaccine designs.

0:00:35.371,0:00:39.211
Once these are vetted in the lab, [br]they enter clinical testing,

0:00:39.211,0:00:44.291
where vaccines are evaluated [br]for safety, efficacy, and side effects

0:00:44.291,0:00:47.116
across a variety of populations.

0:00:47.116,0:00:49.556
Finally, there’s manufacturing,

0:00:49.556,0:00:53.787
where vaccines are produced [br]and distributed for public use.

0:00:53.787,0:00:59.287
Under regular circumstances, this process[br]takes an average of 15 to 20 years.

0:00:59.287,0:01:03.287
But during a pandemic, [br]researchers employ numerous strategies

0:01:03.287,0:01:06.027
to move through each stage [br]as quickly as possible.

0:01:06.027,0:01:09.627
Exploratory research is perhaps [br]the most flexible.

0:01:09.627,0:01:12.617
The goal of this stage [br]is to find a safe way

0:01:12.617,0:01:16.932
to introduce our immune system [br]to the virus or bacteria.

0:01:16.932,0:01:21.392
This gives our body the information[br]it needs to create antibodies

0:01:21.392,0:01:24.062
capable of fighting a real infection.

0:01:24.062,0:01:27.762
There are many ways to safely trigger[br]this immune response,

0:01:27.762,0:01:33.192
but generally, the most effective [br]designs are also the slowest to produce.

0:01:33.192,0:01:37.342
Traditional attenuated vaccines [br]create long lasting resilience.

0:01:37.342,0:01:39.912
But they rely on weakened viral strains

0:01:39.912,0:01:44.553
that must be cultivated in non-human[br]tissue over long periods of time.

0:01:44.553,0:01:47.994
Inactivated vaccines take [br]a much faster approach,

0:01:47.994,0:01:53.744
directly applying heat, acid, or radiation[br]to weaken the pathogen.

0:01:53.744,0:01:58.216
Sub-unit vaccines, that inject [br]harmless fragments of viral proteins,

0:01:58.216,0:02:00.466
can also be created quickly.

0:02:00.466,0:02:05.001
But these faster techniques produce[br]less robust resilience.

0:02:05.001,0:02:08.121
These are just three [br]of many vaccine designs,

0:02:08.121,0:02:10.651
each with their own pros and cons.

0:02:10.651,0:02:13.631
No single approach is guaranteed to work,

0:02:13.631,0:02:16.891
and all of them require [br]time-consuming research.

0:02:16.891,0:02:20.151
So the best way to speed things up [br]is for many labs

0:02:20.151,0:02:23.381
to work on different models [br]simultaneously.

0:02:23.381,0:02:25.681
This race-to-the-finish strategy

0:02:25.681,0:02:29.938
produced the first testable [br]Zika vaccine in 7 months,

0:02:29.938,0:02:35.088
and the first testable COVID-19 vaccine[br]in just 42 days.

0:02:35.088,0:02:39.088
Being testable doesn’t mean [br]these vaccines will be successful.

0:02:39.088,0:02:42.208
But models that are deemed safe [br]and easily replicable

0:02:42.208,0:02:47.387
can move into clinical testing while other[br]labs continue exploring alternatives.

0:02:47.387,0:02:51.896
Whether a testable vaccine is produced[br]in four months or four years,

0:02:51.896,0:02:56.932
the next stage is often the longest and [br]most unpredictable stage of development.

0:02:56.932,0:03:02.184
Clinical testing consists of three phases,[br]each containing multiple trials.

0:03:02.184,0:03:07.084
Phase I trials focus on the intensity [br]of the triggered immune response,

0:03:07.084,0:03:10.924
and try to establish that the vaccine [br]is safe and effective.

0:03:10.924,0:03:15.229
Phase II trials focus on determining [br]the right dosage and delivery schedule

0:03:15.229,0:03:17.449
across a wider population.

0:03:17.449,0:03:19.939
And Phase III trials determine safety

0:03:19.939,0:03:23.519
across the vaccine’s primary [br]use population,

0:03:23.519,0:03:27.837
while also identifying rare side effects[br]and negative reactions.

0:03:27.837,0:03:31.987
Given the number of variables [br]and the focus on long-term safety,

0:03:31.987,0:03:35.987
it’s incredibly difficult to speed up [br]clinical testing.

0:03:35.987,0:03:39.397
In extreme circumstances, [br]researchers run multiple trials

0:03:39.397,0:03:41.777
within one phase at the same time.

0:03:41.777,0:03:46.067
But they still need to meet [br]strict safety criteria before moving on.

0:03:46.067,0:03:49.917
Occasionally, labs can expedite [br]this process by leveraging

0:03:49.917,0:03:52.577
previously approved treatments.

0:03:52.577,0:03:58.763
In 2009, researchers adapted [br]the seasonal flu vaccine to treat H1N1—

0:03:58.763,0:04:03.776
producing a widely available vaccine[br]in just six months.

0:04:03.776,0:04:08.267
However, this technique only works[br]when dealing with familiar pathogens

0:04:08.267,0:04:11.897
that have well-established [br]vaccine designs.

0:04:11.897,0:04:16.560
After a successful Phase III trial, [br]a national regulatory authority

0:04:16.560,0:04:21.102
reviews the results and approves [br]safe vaccines for manufacturing.

0:04:21.102,0:04:25.782
Every vaccine has a unique blend [br]of biological and chemical components

0:04:25.782,0:04:29.492
that require a specialized pipeline [br]to produce.

0:04:29.492,0:04:32.392
To start production as soon [br]as the vaccine is approved,

0:04:32.392,0:04:37.754
manufacturing plans must be designed[br]in parallel to research and testing.

0:04:37.754,0:04:42.086
This requires constant coordination[br]between labs and manufacturers,

0:04:42.086,0:04:46.905
as well as the resources to adapt[br]to sudden changes in vaccine design—

0:04:46.905,0:04:50.605
even if that means scrapping[br]months of work.

0:04:50.605,0:04:54.435
Over time, advances in exploratory[br]research and manufacturing

0:04:54.435,0:04:56.835
should make this process faster.

0:04:56.835,0:04:59.445
Preliminary studies suggest [br]that future researchers

0:04:59.445,0:05:03.335
may be able to swap genetic material[br]from different viruses

0:05:03.335,0:05:06.105
into the same vaccine design.

0:05:06.105,0:05:11.159
These DNA and mRNA based vaccines[br]could dramatically expedite

0:05:11.159,0:05:13.819
all three stages of vaccine production.

0:05:13.819,0:05:15.949
But until such breakthroughs arrive,

0:05:15.949,0:05:19.943
our best strategy is for labs [br]around the world to cooperate

0:05:19.943,0:05:22.743
and work in parallel [br]on different approaches.

0:05:22.743,0:05:24.983
By sharing knowledge and resources,

0:05:24.983,0:05:28.785
scientists can divide and conquer [br]any pathogen.