Incredible images reveal how AstraZeneca's vaccine turns cells into 'little factories' that produce spike proteins just like the virus to fight off Covid-19
- Researchers gave the vaccine to human cells in a lab and imaged the result
- The jab forces the injected person's own cells to make replicas of real virus spike
- The immune system remembers the shape of the spike and how to defeat it so that if a person gets infected in the future then they can rapidly fight the virus Scientists have produced stunning images showing exactly what happens to the cells of a person who is injected with the Oxford-AstraZeneca Covid-19 vaccine.
Images reveal how the jab forces the injected person's own cells to make replicas of the real coronavirus spike, a glycoprotein, which sticks out from its surface.
The spikes on the surface of the host's own cells are then recognised as a foreign invader by the immune system and attacked with antibodies.The immune system remembers the shape of the spike and how to defeat it so that if a person does get infected in the future then they can rapidly fight off the virus.
Analysis of the spike protein replicas made by the human cells after injection with the Oxford jab reveals the vaccine-induced spikes are almost identical to those of the virus
The AstraZeneca jab is under criticism at the moment for purported side-effects which may cause blood clots in a very small percentage of people.
But the vaccine is highly effective at protecting against Covid-19 and has been given to millions of Britons, with the 100 million doses ordered by the Government making up a quarter of the UK's stockpile.
Researchers from the University of Oxford worked with Professor Max Crispin of the University of Southampton, an expert in virology and glycoproteins, to see how good their vaccine was at imitating the coronavirus spike.
Human cells in a laboratory were exposed to the vaccine and after two days the researchers looked at the shape and structure of the imitation spikes.
The method of analysis is called cryo-electron microscopy (cryoEM) and thousands of images were taken and combined as part of the study.
Study co-author Professor Peijun Zhang, of the University of Oxford led the imaging work.
'CryoEM is an immensely powerful technique which enabled us to visualise the dense array of spikes that had been manufactured and presented on the surface of the cells,' she said.
Analysis of the glycoproteins themselves revealed the vaccine-induced spikes are almost identical to those of the virus.
'In this study we set out to see how closely the vaccine induced spikes resembled those of the infectious virus.
'We were really pleased to see a large amount of native-like spikes,' Professor Crispin said.
'This study will hopefully provide further understanding for the public, helping them see how the Oxford-AstraZeneca vaccine works.
'Many people may not realise how their cells become little factories manufacturing viral spikes that then trigger the immune response needed to fight off the disease.
'This may also provide reassurance that the vaccine is doing its job and generating the material that we need to present to our immune systems.'
The study has been published in the journal ACS Central Science.
Scientists have produced stunning images showing exactly what happens to the cells of a person who is injected with the Oxford-AstraZeneca Covid-19 vaccine. Pictured, a graphic based on the new imaged showing how the vaccine (left) turns the cells of a person who has been injected into 'little factories manufacturing viral spikes that then trigger the immune response needed to fight off the disease' (right)
Professor Max Crispin previously found that the coronavirus (pictured) is not as heavily protected or disguised as some viruses, such as HIV. He said the spike proteins are disguised by the virus, which allows to to be a 'wolf in sheep's clothing'The key to a successful vaccine is ensuring the imitation spike protein it produces is as close to that of the real virus as possible.
There are several ways to do this, including the mRNA method of both Pfizer/BioNtech and Moderna and an inactivated whole virus.
But the Oxford/AstraZeneca jab uses a different technique based on a common cold virus found in chimps.
The team inactivated the ape virus and inserted a piece of the coronavirus' genetic code into it which is responsible for the production of the critical spike protein.
The coronavirus spike protein is how the virus infects people. The nefarious protein attaches to the common ACE2 receptor on human cells and hijacks it, using it as a gateway to infect human cells.
But while the spike protein is how SARS-CoV-2 infects people, it is also how it is most easily recognised.
Once a person receives the Oxford jab, known as the ChAdOx1 nCoV-19 vaccine, their cells then get infected by the harmless modified chimp virus.
Then, the person's own cells read the coronavirus' genetic code and produce a replica of the spike protein on their surface.
How accurately these mimic spikes resemble those of the virus determine the robustness of a person's immunity.
The concern for vaccine developers and academics is that new variants of coronavirus, such as those first spotted in Brazil and South Africa, have specific mutations which change the shape of the spike.
This, they believe, could lower immunity provided by vaccines as the new spike seen on variants is significantly different to that of the vaccine.
Therefore, the person who has been inoculated has antibodies which do not work on the new strain, rendering them unprotected and vulnerable to infection.
Studies and trials have found that the Oxford jab does work against the emerging strains, but not as well as it does against the original version of the disease and the Kent strain.
The jab is under scrutiny for a concerning link to blood clots in younger people MPS today said Britain's drug regulator the MHRA must urgently finish its review into the link between the Covid vaccine and a rare brain blood clot called CVST.
Last night Oxford University halted trials of its coronavirus vaccine in children until the Medicines and Healthcare products Regulatory Agency (MHRA) concluded on its safety in younger people, with formal advice expected in as early as today.
Health watchdogs continue to probe the link between the jab and CVST, which can lead to a stroke, with the European medical regulators set to announce the conclusions of their investigation at 3pm.
Germany has already temporarily banned the vaccine for under-60s and France making the same controversial move for under-55s.
How does the Oxford-Astrazeneca vaccine work?
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