Coronavirus: ‘Several’ vaccines could be ready by end of year

What type of vaccine is it? 

The vaccine is called AZD1222 and is made from a weakened version of a common cold virus (adenovirus) from chimpanzees that has been genetically changed so it is impossible for it to grow in humans.

The intellectual rights to its vaccine are owned by the University of Oxford and a spin-out company called Vaccitech. 

Clinical teams at the Oxford University’s Jenner Institute and Oxford Vaccine Group began developing the vaccine in January.  

It’s a type of immunisation known as a recombinant viral vector vaccine. 

Researchers place genetic material from the coronavirus into another virus that’s been modified. They will then inject the virus into a human, hoping to produce an immune response against SARS-CoV-2. 

This virus, weakened by genetic engineering, is a type of virus called an adenovirus, the same as those which cause common colds, that has been taken from chimpanzees. 

If the vaccines can successfully mimic the spikes inside a person’s bloodstream, and stimulate the immune system to create special antibodies to attack it, this could train the body to destroy the real coronavirus if they get infected with it in future.

It was developed so rapidly by Sarah Gilbert, a professor of vaccinology, and her team because they already had a base vaccine for similar coronaviruses. 

The team have gone through stages of vaccine development that usually take five years in just four months.  

However, Professor Gilbert said that none of the normal safety steps had been missed out.  

Will it be successful?

Professor Gilbert has been vocal about her confidence in the vaccine. 

She acknowledged nobody can be ‘completely certain’ that it is possible to find a vaccine for Covid-19, but the prospects are ‘very good’.

In an interview before trials began, Professor Gilbert told the paper she is ’80 per cent’ confident of its success, ‘based on other things that we have done with this type of vaccine’.

University of Oxford scientists are confident they can get the jab for the incurable virus rolled out for millions to use by autumn. 

But Sir Patrick Vallance, the chief scientific advisor to the Government, has said expectations for a vaccine need to be tempered. 

Writing in The Guardian ahead of the Oxford trials, Sir Patrick wrote: ‘All new vaccines that come into development are long shots; only some end up being successful, and the whole process requires experimentation. This will take time, and we should be clear it is not a certainty.’ 

What obstacles will the team face? 

Some obstacles are expected to emerge while searching for a vaccine. For example, if transmission levels of COVID-19 levels drop in the community, it could hamper the Oxford study. 

Professor Gilbert has said they may have to continue their trials in other countries where more of the virus is circulating in the community. 

In this case, it could be at least six months before researchers know if the vaccine works. If transmission remains high in the UK, the team could get data within a couple of months.  

Andrew Pollard, who is part of the Oxford team, said there may be hurdles when testing the vaccine on older people.

‘For most vaccines the immune system in older adults, particularly those over 70, doesn’t make such good responses,’ he said.

‘If we did see weaker responses in older adults we also have in our plan that we would look at giving additional doses in that age group to try and improve the immune response.’ 

Professor Gilbert had previously said her team needed help manufacturing the jabs, warning the UK did not have the facilities to do it alone, before a deal was struck with AstraZeneca.

How does it compare to other vaccines? 

According to the World Health Organisation, 118 COVID-19 vaccines are in development worldwide as of May 15. But the UK now joins only the United States and China in beginning human trials. Eight vaccine candidates are now in preclinical trials.