This is how the Pfizer, Oxford and Moderna Covid-19 vaccines differ
The UK has now approved three different vaccines to be deployed in the fight against the coronavirus pandemic.
Though all three vaccines have proven effective in protecting recipients against coronavirus, they differ slightly from one another in certain aspects, such as the method of protection and the storage conditions in which they must be kept.
This is how each vaccine works, and how they differ from one another.
The first vaccine to be approved by UK health authorities, the Pfizer vaccine was developed in Germany, and was the first coronavirus vaccine to be administered anywhere in the world.
The Pfizer jab uses technology known as mRNA (messenger RNA) to provide protection against the virus.
This vaccine introduces a messenger sequence into the body which contains genetic instructions to cells, allowing them to produce antigens to coronavirus, thus generating an immune response in the body.
In trials, the Pfizer vaccine was found to be 95 per cent effective against coronavirus.
One of its downsides, however, is that it must be kept at a temperature of -70C, making it more difficult to store and distribute than the Oxford/AstraZeneca vaccine.
It will be administered in two separate doses, at an interval of between four and 12 weeks.
University of Oxford/AstraZeneca
The Oxford vaccine, developed in the UK and already rolled out to some recipients across the country, works in a different way to the Pfizer vaccine.
This jab works by smuggling the coronavirus gene into human cells through a harmless virus, allowing cells to create the “spike protein”, a key biological characteristic of Covid-19.
The body responds to this by building up an immune response. This means that if the recipient later catches coronavirus, they already have antibodies and T-cells to fight it.
It’s a jab that’s much easier to store and distribute than the Pfizer vaccine, given it can be stored at a normal fridge temperature. This means it can be distributed in GP surgeries and pharmacies.
Trials of this vaccine showed a 62 per cent effectiveness, though some data showed that when people were given a half dose followed by a full dose, effectiveness hit 90 per cent.
This data was not clear enough, however, to approve the ‘half dose, full dose’ method, and the UK’s medicines regulator concluded that delaying the second dose by three months brought effectiveness to 80 per cent.
Like the Pfizer jab, the Oxford vaccine will be administered in two doses at an interval of between four and 12 weeks.
The Moderna vaccine uses the same mRNA technology as the Pfizer jab to protect against coronavirus, using genetic instructions that allow the body to create an immune response to the virus.
The US-based company's vaccine was shown to have 94 per cent efficacy against coronavirus in final trials, and an additional 10 million doses have been ordered by the UK.
It’s expected, however, that they won’t be rolling out the Moderna vaccine in the UK until March 2021.
Again, two doses are needed, at an interval of approximately four weeks apart.
Moderna is said to be easier to store and move, lasting up to 30 days in household fridges and up to 12 hours at room temperature.