How fast can a vaccine be made? - Dan Kwartler

When a new pathogen emerges,

our bodies and healthcare systems
are left vulnerable.

In times like these,
there’s an urgent need

for a vaccine to create widespread
immunity with minimal loss of life.

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

Vaccine development can generally be
split into three phases.

In exploratory research, scientists
experiment with different approaches

to find safe and replicable
vaccine designs.

Once these are vetted in the lab,
they enter clinical testing,

where vaccines are evaluated
for safety, efficacy,

and side effects across a variety
of populations.

Finally, there’s manufacturing,

where vaccines are produced
and distributed for public use.

Under regular circumstances, this process
takes an average of 15 to 20 years.

But during a pandemic, researchers
employ numerous strategies

to move through each stage
as quickly as possible.

Exploratory research is perhaps the
most flexible.

The goal of this stage is
to find a safe way

to introduce our immune system
to the virus or bacteria.

This gives our body the information it
needs to create antibodies

capable of fighting a real infection.

There are many ways to safely trigger
this immune response,

but generally, the most effective
designs are also the slowest to produce.

Traditional attenuated vaccines create
long lasting resilience.

But they rely on weakened viral strains

that must be cultivated in non-human
tissue over long periods of time.

Inactivated vaccines take a much
faster approach, directly applying heat,

acid, or radiation to weaken the pathogen.

Sub-unit vaccines, that inject harmless
fragments of viral proteins,

can also be created quickly.

But these faster techniques produce
less robust resilience.

These are just three of many vaccine
designs,

each with their own pros and cons.

No single approach is guaranteed to work,

and all of them require
time-consuming research.

So the best way to speed things up is for
many labs

to work on different models
simultaneously.

This race-to-the-finish strategy

produced the first testable
Zika vaccine in 7 months,

and the first testable COVID-19 vaccine
in just 42 days.

Being testable doesn’t mean these
vaccines will be successful.

But models that are deemed safe
and easily replicable

can move into clinical testing while other
labs continue exploring alternatives.

Whether a testable vaccine is produced
in four months or four years,

the next stage is often the longest and
most unpredictable stage of development.

Clinical testing consists of three phases,
each containing multiple trials.

Phase I trials focus on the intensity of
the triggered immune response,

and try to establish that the vaccine
is safe and effective.

Phase II trails focus on determining
the right dosage and delivery schedule

across a wider population.

And Phase III trials determine safety

across the vaccine’s primary
use population,

while also identifying rare side effects
and negative reactions.

Given the number of variables and
the focus on long-term safety,

it’s incredibly difficult to speed up
clinical testing.

In extreme circumstances, researchers
run multiple trials

within one phase at the same time.

But they still need to meet strict
safety criteria before moving on.

Occasionally, labs can expedite this
process by leveraging

previously approved treatments.

In 2009, researchers adapted the seasonal
flu vaccine to treat H1N1 –

producing a widely available vaccine
in just six months.

However, this technique only works
when dealing with familiar pathogens

that have well-established
vaccine designs.

After a successful Phase III trial,
a national regulatory authority

reviews the results and approves
safe vaccines for manufacturing.

Every vaccine has a unique blend
of biological and chemical components

that require a specialized pipeline
to produce.

To start production as soon as the
vaccine is approved,

manufacturing plans must be designed
in parallel to research and testing.

This requires constant coordination
between labs and manufacturers,

as well as the resources to adapt
to sudden changes in vaccine design –

even if that means scrapping
months of work.

Over time, advances in exploratory
research and manufacturing

should make this process faster.

Preliminary studies suggest that future
researchers

may be able to swap genetic material
from different viruses

into the same vaccine design.

These DNA and mRNA based vaccines
could dramatically expedite

all three stages of vaccine production.

But until such breakthroughs arrive,

our best strategy is for labs around the
work to cooperate and work in parallel

on different approaches.

By sharing knowledge and resources,

scientists can divide and
conquer any pathogen.