As covid-19’s global impact mounts...
...so does the urgent need to stop its spread
A vaccine is what we need for life...
...to get back to some sort of semblance of normality
Scientists are working as quickly as they can
But that’s at least a year, a year-and-a-half, two years away...
In the meantime scientists are trialling existing drugs...
...to treat covid-19
The coronavirus which causes covid-19...
...was only identified in January this year
A mysterious pneumonia outbreak in China has been identified
It’s from the same family that caused the deadly...
...SARS epidemic 17 years ago
But scientists have known about coronaviruses since the 1960s
Giving them a head start in understanding it
And that meant that when this current, new strain appeared...
...there was quite a lot of understanding of the basic biology
SARS-CoV-2, which is the new coronavirus, has a very similar...
...structure to previous coronaviruses
And by understanding the biology and structure of that virus...
...we can start to look for ways to attack it
The virus has an outer membrane made up of fatty molecules...
...which scientists call lipids
Spike proteins float on this lipid membrane...
...and provide the virus particle with the appearance of a crown...
...giving the coronavirus its name
Inside is a molecule of RNA...
...a chemical similar to DNA...
...on which the virus’s genome is written
When the virus gets inside the body...
...the spike proteins link up with proteins found...
...on the surface of cells in the lung’s airways
This lets the virus break into the patient’s cells
Inside it releases the RNA that carries the virus’s genes
Those genes hijack the cell’s protein-making machinery...
...to produce the building blocks for more virus particles
One specific gene called replicase...
...provides the instructions to build a molecular machine...
...that copies the virus’s RNA...
...making enough for up to 1,000 new virus particles
The new particles are then released from the cell...
...to attack other cells, spreading the virus
It’s this replicase system that has become a focus...
...for scientists searching for an effective treatment
The replicase system within the virus is actually a good target...
...for disrupting how the virus works...
...because healthy human cells don’t actually copy RNA within them
So, what you could do is if you could disrupt...
...the replicase system in the virus...
...you’d hopefully destroy the virus without harming human cells
But developing a new drug from scratch that could do this...
...and running the trials needed to ensure the drug...
...is safe for humans could take months or even years
During a pandemic every month you spend trying to do research...
...more people will potentially suffer or die
And so that’s why there’s a move to try and repurpose existing drugs
If you’ve already got a drug available for something else...
...you know that it’s probably safe for humans...
...and so you can speed up the whole process
One of the drugs seen as most promising...
...is called remdesivir
It was originally developed to treat Ebola...
...by blocking the replicase system
It was found to be safe for humans...
...but was shelved in favour of a more effective treatment
The molecules in remdesivir look like the molecules...
...that the replicase system uses to make RNA
When this drug gets into a cell...
...the virus tries to use the drug molecules to replicate...
...and then it basically doesn’t work...
...so the virus doesn’t manage to replicate properly
And there are other drugs on the market...
...that scientists believe could also make it harder...
...for the virus to replicate itself
There’s also another drug called Kaletra...
...which is used to treat HIV at the moment...
...in combination with other therapies
It was tried during the original SARS outbreak in 2003...
...and seemed to offer some benefits
What that does is target the enzymes that...
..chop up big proteins into smaller proteins...
...during the replication process of a virus
So, if you can disrupt that...
...perhaps that’s another way to stop it from replicating within cells
Both remdesivir and Kaletra are now being tested...
...as part of a global mega-trial...
...set up by the World Health Organisation in March
The WHO study will also put the anti-malarial chloroquine to the test
President Donald Trump has built up a lot of hype...
...around hydroxychloroquine, a similar drug which works in the same way
We’re going to be able to make that drug available almost immediately
Based on what I see it could be a game-changer
But the president’s enthusiasm is damagingly ill-informed
In the lab it seems chloroquine may reduce the virus particle’s ability...
...to get into cells and to reproduce
But in patients there is no strong evidence as yet...
...that the drug can treat covid-19
The WHO study should provide a definitive answer...
...on chloroquine and the other drugs it’s testing
What the World Health Organisation is trying to do...
...is speed up the process by just trialling more people...
...and that will hopefully allow them to pick up...
...even very marginal benefits of the drugs...
...pick up very small side-effects as well
And then using all of that information...
...it might just help these systems understand how to reduce...
...the number of days someone is infected
Reducing the number of days someone is ill for...
...can prove vitally important
Even very small differences in the length of time...
...someone’s ill can have an enormous knock-on...
...benefits for a health system
If you can knock five days off the amount of time...
...someone needs to be in hospital, or needs a ventilator...
...you can treat more people with the same number of ventilators...
...with the same number of doctors
An effective vaccine is the only definitive...
...way to halt the spread of coronavirus
But while the world waits for that...
...repurposing existing drugs could help doctors treat it
Allowing patients, health systems, and countries...
...that are coming under intolerable strain to find a little respite
We’re dedicated to bringing you the most up-to-date reporting...
...and analysis on this rapidly changing story
So, clicking on the link opposite it will take you to...
...all of our coronavirus coverage
Thank you for watching