Oxford vs Pfizer vaccine… which Covid jab is best?
BRITAIN'S Covid vaccine programme is well underway with two different jabs in use - and more on the way.
Experts now say data suggests that both the Pfizer and Oxford vaccines reduce Covid deaths, hospitalisations and transmission.
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But which of the UK's two Covid jabs is best?
Well, directly comparing vaccines is difficult as none of them have been tested in this way.
However as the vaccination rollout continues, scientists are constantly gathering more data to better understand their effectiveness.
How effective is each jab?
New data from two separate studies - one in England and another in Scotland - have shown Covid-19 vaccines are effective in cutting disease transmission and hospitalisations from the first dose.
Just one shot of the Oxford/AstraZeneca Covid jab slashes older people’s risk of being taken to hospital with the disease by 94 per cent, figures show.
It is the first time the British-made vaccine has been proven to protect over-65s against the disease.
Sir Patrick Vallance, the Government’s chief scientific adviser, said: “It is clear that AstraZeneca works and it works in older people.”
The findings are based on an analysis of the impact of the first 1.1million jabs given in Scotland.
It shows four weeks after the initial Oxford vaccine — which was mostly given to over-65s — the risk of Covid hospitalisation fell by 94 per cent.
While separate analysis from Public Health England found the Pfizer/BioNTech vaccine reduces the risk of catching infection by more than 70 per cent after a first dose.
That risk is reduced by 85 percent after a second dose.
The study of real-world data also showed vaccinated people who go on to become infected are far less likely to die or be hospitalised.
Hospitalisation and death from Covid-19 is reduced by over 75 per cent in those who have received a dose of the Pfizer/BioNTech vaccine, according to the analysis.
And Public Health England called that “the lower end of the estimate”.
Health Secretary Matt Hancock said:"This crucial report shows vaccines are working -- it is extremely encouraging to see evidence that the Pfizer vaccine offers a high degree of protection against coronavirus."
Pooled data on both vaccines shows that in the over-80s — the highest risk group for Covid deaths — the chances of needing a stay in hospital fell by 81 per cent.
Meanwhile, separate research following 23,324 NHS workers suggests a single dose of the Pfizer jab was enough to cut virus transmission by around 70 per cent.
And two doses resulted in 85 per cent fewer positive swabs among frontline NHS staff.
Hospital admissions for the disease are down nearly three-quarters from their second-wave peak, according to NHS England.
Comparing costs
The Oxford vaccine is believed to be relatively cheap to make - with estimates at around £3 per jab.
The Pfizer/BioNTech jab is more expensive and costs around £15 a jab.
Both AstraZeneca and Pfizer has said it will not sell the jab for profit - allowing it to be available to all countries.
Pfizer and BioNTech produced around 50 million vaccine doses globally in 2020 and will make up to 1.3 billion in 2021.
The jab can also be kept at room temperature - meaning it will be easier to transport and therefor easier to roll out.
The Pfizer jab has to be kept at -70C and can only be thawed in batches of 1,000 before immunisation.
AstraZeneca said it aimed to supply millions of doses in the first quarter of 2021 as part of an agreement with the Government to supply up to 100 million doses.
Its chief executive Pascal Soriot said the vaccine "has been shown to be effective, well-tolerated, simple to administer and is supplied by AstraZeneca at no profit".
How do the jabs work?
The Oxford Covid vaccine uses a harmless, weakened version of a common virus which causes a cold in chimpanzees.
Researchers have already used this technology to produce vaccines against a number of pathogens including flu, Zika and Middle East Respiratory Syndrome (Mers).
The virus is genetically modified so that it is impossible for it to grow in humans.
Scientists have transferred the genetic instructions for coronavirus's specific "spike protein" - which it needs to invade cells - to the vaccine.
When the vaccine enters cells inside the body, it uses this genetic code to produce the surface spike protein of the coronavirus.
This induces an immune response, priming the immune system to attack coronavirus if it infects the body.
Pfizer said there had been 170 cases of the disease in its trial of more 43,000 volunteers, of which 162 were observed in the placebo arm and eight were in the vaccine group.
Ten people developed severe Covid-19, one of whom received the vaccine.
It also said the vaccine was well-tolerated and that side effects were mostly mild to moderate and cleared up quickly.
The only severe adverse event that affected more than two per cent of those vaccinated was fatigue, which affected 3.8 per cent of recipients after the second dose.
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Older adults tended to report fewer and milder solicited adverse events following vaccination.
The Pfizer jab is known as a messenger vaccine (MRNA) which uses genetic code rather than a weakened form of the virus.
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This is injected into the body where it enters cells - the vaccine the tells them to create antigens.
In turn the antigens are recognised by the immune system and then fight the coronavirus.