ITV News Science Editor Tom Clarke reports from the lab behind the AstraZeneca vaccine
Current vaccines may work against new variants – but scientists are hurrying to update them just in case they don’t.
I’m standing in the middle of a very ordinary looking laboratory at Oxford University.
It has the usual collection cabinets, freezers and incubators used for the study of molecular biology.
But this unremarkable lab will likely feature in the history of the Covid-19 pandemic.
It was here that one of the first vaccines against Covid was created – the Oxford/AstraZeneca jab.
The birthplace of the vaccine, in more ways than one.
Because the vaccine is produced using a harmless virus growing in test tubes – every single one of the tens of millions of doses of the jab administered around the world so far descended from that original batch of vaccine-virus created in this lab.So why are we back here, long after the manufacturing of the vaccine has moved on to major industrial labs around the world?
Well because new variants of Covid-19 mean the original vaccine they produced may need an urgent makeover.
Vaccines work by mimicking the shape of the thing you want to protect the body against.
In the case of Covid-19, all our vaccines designed around the shape of the virus’ «spike protein»: the bits on the surface of Covid which, as the name suggests, sticks out of it like spikes and helps the virus infect our cells.
The vaccines are working well – really well. Evidence suggests that up to 95% of people vaccinated (with both doses of a jab) are protected against severe disease and death from Covid.
People’s immune systems are responding to the shape of the spike protein in the vaccine so that when they encounter Covid for real, there are antibodies ready and waiting to destroy it 95% of the time.
The problem with new variants of Covid is that their spike proteins are a different shape.
If the difference between the shape of the spike protein in a new variant and «classic» Covid, the immune system won’t recognise the new virus – or won’t recognise it well enough – and the virus may be able to infect and kill.
Evidence from labs suggest this may be the case. Antibodies made against the vaccine can be eight to 10 times less effective at binding to new variants of the virus, like the ones circulating in South Africa of Brazil.
Evidence from the real world is slightly more reassuring. Clinical trials in places like South Africa demonstrate the vaccines are less effective at preventing people from getting infected but there is some evidence they’re good enough to prevent severe disease.
But when it comes to protecting billions of people from a fast mutating virus, public health experts aren’t prepared to take the risk.
It’s why all the major developers of Covid vaccines are currently working on new versions of their jabs tuned to recognise the changing shapes of new variants.
Fortunately for these companies, and us, it shouldn’t be too difficult a job.
The original, highly effective jabs, were created using just the genetic code of the spike protein.
New vaccines can be made simply by swapping out the code of classic Covid, with the code of the new variant.
If your phone was a vaccine, think of this like a software update, rather than having to go out and buy a whole new handset.
Not only does that make it easier for the vaccines to be upgraded, it also means they won’t have to go through the same lengthy clinical trial process they did before.
The view of most drug regulators is that if its only the genetic code in the vaccine that’s changed, it shouldn’t make the updated vaccine any different from a safety point of view as its predecessor.
All the scientists need to do is prove their vaccines are effective.
The other challenge is knowing which new variant to make your vaccine against. As we’re seeing in places like India right now, large outbreaks give the virus more and more opportunities to mutate.
How do you know if your new variant vaccine won’t be proved redundant by the time you’ve produced it.
Here in Oxford, they’re taking the shotgun approach. Because changing the genetic code in the vaccine can be done relatively easily, each time a new variant comes along, they’re making a new vaccine and then putting it in the freezer in case it’s the one that turns out to present the biggest problem as the pandemic evolves.
Each of the four cabinets in the lab is labelled with a code number dedicated to whichever new vaccine strain they’re working on.
At the time of writing, they’ve created 12 with a pipeline of new variants being constantly updated based on the advice of experts in virus evolution.
And because the vaccine is based on a virus they’re able to grow in the lab, they can create as much as they want, once they’ve made the first batch.
«We like to think of it like a sourdough starter,» says Dr Catherine Green who leads the project at the University of Oxford.
«Our process of manufacturing can be exponential. We start very small but then it grows so we can use each stage to seed the next and to seed the next.»