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 trials 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 world to cooperate
and work in parallel
on different approaches.
By sharing knowledge and resources,
scientists can divide and conquer
any pathogen.
