The COVID-19 vaccine made by Oxford University and AstraZeneca has been hailed as a triumph for British science.
Brits started receiving the “game-changing” jab on 4 January 2021 – with millions more vaccinations expected throughout 2021. The vaccine is mainly being produced in the UK, though other sites across Europe are being used to manufacture the first doses of the jab.
30 December 2020
How does the Oxford University / AstraZeneca vaccine work in the body when taken?
Viral vector (genetically modified virus).
The COVID-19 virus uses proteins on its outer surface, called spike proteins, to enter the body’s cells and cause disease.
The vaccine is made up of another virus (of the adenovirus family) that has been modified to contain the gene for making the SARS-CoV-2 (COVID-19) spike protein (the part of the virus that allows it to enter human cells). The adenovirus itself cannot reproduce and does not cause disease.
Once it has been given, the vaccine delivers the SARS-CoV-2 gene into cells in the body. The cells will use the gene to produce the spike protein. The person’s immune system will treat this spike protein as foreign and produce natural defences − antibodies and T cells − against this protein.
If, later on, the vaccinated person comes into contact with SARS-CoV-2, the immune system will recognise the virus and be prepared to attack it: antibodies and T cells can work together to kill the virus, prevent its entry into the body’s cells and destroy infected cells, thus helping to protect against COVID-19.
What are the ingredients of the Oxford University / AstraZeneca vaccine?
One dose (0.5 ml) contains: COVID-19 Vaccine (ChAdOx1-S* recombinant) 5 × 10^10 viral particles.
*Recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS CoV 2 Spike glycoprotein. Produced in genetically modified human embryonic kidney (HEK) 293 cells.
This product contains genetically modified organisms (GMOs).
The other ingredients are:
Water for injections
L-Histidine hydrochloride monohydrate
Magnesium chloride hexahydrate
Disodium edetate dihydrate
You should not take the vaccine if you have ever had a severe allergic reaction to any of the ingredients.
How is the Oxford University / AstraZeneca vaccine administered?
The vaccine is only being administered to people in a safe health care environment with facilities to treat allergic reactions if they do occur. Do not take the vaccine from anyone else. If offered by anyone, and you are in doubt, contact your GP.
The Oxford University / AstraZeneca vaccine is injected into a muscle (usually in the upper arm).
You will receive 2 injections. You will be told when you need to return for your second injection.
The vaccination course consists of two separate doses of 0.5ml each. The second dose should be administered between 4 and 12 weeks after the first dose.
It is recommended that individuals who receive a first dose of Oxford University / AstraZeneca vaccine should complete the vaccination course with the same vaccine.
During and after each injection of the vaccine, your doctor, pharmacist or nurse will watch over you for around 15 minutes to monitor for signs of an allergic reaction.
Are there any possible risks and/or side effects of the Oxford University / AstraZeneca vaccine?
Nothing in medicine comes without risks – even something we take without thinking, like paracetamol, may pose a risk.
Like all medicines, this vaccine can cause side effects, although not everybody gets them. In clinical studies with the vaccine, most side effects were mild to moderate in nature and resolved within a few days with some still present a week after vaccination.
If side effects such as pain and/or fever are troublesome, medicines containing paracetamol can be taken. But always speak to a doctor first.
Side effects can include:
Very common (may affect more than 1 in 10 people)
Chills or feeling feverish
Generally feeling unwell
Muscle ache & joint pain
Swelling where injection is given
Bruising where injection is given
Common (may affect up to 1 in 10 people)
Flu-like symptoms such as high temperature, sore throat, runny nose, cough and chills
A lump at the injection site
Uncommon (may affect up to 1 in 100 people)
Enlarged lymph nodes
Excessive sweating, itchy skin or rash
In clinical trials there were very rare reports of events associated with inflammation of the nervous system, which may cause numbness, pins and needles, and/or loss of feeling. However, it is not confirmed whether these events were due to the vaccine.
If you notice any side effects not mentioned here, please inform your doctor, pharmacist or nurse.
Warnings and Precautions
Talk to your doctor, pharmacist or nurse before you are given this vaccine if you:
If you have ever had a severe allergic reaction (anaphylaxis) after any other vaccine injection.
If you currently have a severe infection with a high temperature (over 38°C). However, a mild fever or infection, like a cold, are not reasons to delay vaccination.
If you have a problem with bleeding or bruising, or if you are taking a blood thinning medicine (anticoagulant).
If your immune system does not work properly (immunodeficiency) or you are taking medicines that weaken the immune system (such as high-dose corticosteroids, immunosuppressants or cancer medicines).
Do NOT take the vaccine if
you have ever had a severe allergic reaction to any of the active substances or any of the other ingredient. Signs of an allergic reaction may include itchy skin rash, shortness of breath and swelling of the face or tongue. Contact your doctor or healthcare professional immediately or go to the nearest hospital emergency department right away if you have an allergic reaction. It can be life-threatening.
If you are not sure if any of the above applies to you, talk to your doctor, pharmacist or nurse before you are given the vaccine.
As with any vaccine, this vaccine may not fully protect all those who receive it.
No data is currently available in individuals with a weakened immune system or who are taking chronic treatment that suppresses or prevents immune responses.