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There have now been three COVID-19 vaccines approved for use in the UK. These are the Pfizer-BioNTech vaccine, the Oxford University/AstraZeneca vaccine, and thirdly, the most recent vaccine to be approved is the Moderna vaccine. Here we explain in more detail about each of the vaccines, including the differences between them and the Government strategy for how they will be rolled out nationwide. All three vaccines have been authorised by the Medicines and Healthcare products Regulatory Agency (MHRA) after meeting strict standards of safety, quality and effectiveness. 

Pfizer – BioNTech vaccine

The vaccine developed by Pfizer-BioNTech was the first vaccine to be approved for use in the UK on the 2nd December 2020 with the UK set to receive 40 million doses and has already started to be given to patients. 

Oxford University – AstraZeneca vaccine

This vaccine, developed by a team at Oxford University and AstraZeneca, was the second vaccine to be approved for use in the UK on the 30th December 2020. The UK has ordered 100 million doses, which have already started to be given to patients.

Moderna Vaccine

The vaccine made by US company Moderna is the latest vaccine to be approved by the UK on the 8th January 2021. However, while the UK have ordered 17 million doses, the supply is not expected to be available until the spring. 

How effective are the vaccines?

The two currently available vaccines (Pfizer-BioNTech and Oxford-AstraZeneca) have an efficacy of between 70% and 90% at preventing COVID-19 symptoms, when measured 3 weeks after the first injection is given; however they are also between 95% and 100% effective at preventing severe symptoms and hospitalisation.

After the second dose of the vaccine, the efficacy increases further, and the duration of its effect is also increased. However, while the vaccine can prevent you from getting COVID symptoms, we don’t yet know if it also stops you from spreading the virus to other people, so it’s still important to follow social distancing guidance, and cover your nose and mouth in places where you are near other people.

How are the vaccines given?

All three vaccines require patients to receive two doses by an injection given in the deltoid muscle in the upper arm. The second dose for the Pfizer-BioNTech vaccine was originally recommended to be given three weeks after the first dose, however this has now been changed to up to 12 weeks. This is because the Government is prioritising giving the first dose to as many ‘at risk’ people as possible, because having the first vaccine alone does provide some protection against coronavirus. The Oxford-AstraZeneca vaccine’s second dose is given up to 12 weeks after the first, and the Moderna vaccine is recommended to have an interval of 28 days between the first and second doses.

Are there any challenges to the vaccines?

This Pfizer-BioNTech vaccine needs to be stored at very low temperatures of around -70C, which means special equipment is needed to transport it. Unlike the Pfizer-BioNTech vaccine, the Oxford-AstraZeneca and Moderna vaccines do not have to be stored at very low temperatures. The Oxford-AstraZeneca vaccine can be stored in a standard pharmaceutical refrigerator and the Moderna vaccine can be stored at -20C which is the temperature of a standard freezer. This means these two vaccines are much easier to transport and distribute to places such as care homes and GP surgeries.

How does the Pfizer-BioNTech vaccine work? 

The Pfizer-BioNTech vaccine is known as a messenger RNA (mRNA) vaccine, which means it uses part of the COVID-19 genetic code. The vaccine is injected into the body where it enters cells and tells them to produce the harmless ‘spike protein’ which is found on the surface of the virus that causes COVID-19. This then causes the immune system to produce antibodies to activate T-cells, ready to destroy any infected cells. If a patient then gets coronavirus in the future, antibodies and T-cells are prepared to fight the virus. 

How does the Oxford-AstraZeneca vaccine work?

This vaccine is called a “vector vaccine” and does not use the virus’s genetic code. Instead it uses a harmless, weakened version of a common cold virus (called an adenovirus) that causes a cold in chimpanzees but doesn’t make humans sick. This was then genetically modified so that it is impossible for it to grow in humans. Scientists have then transferred the genetic instructions for the coronavirus specific ‘spike protein’ to the vaccine. When the vaccine is injected into the patient, it enters cells inside the body and uses this genetic code to produce the surface spike protein of the coronavirus. The body’s immune system reacts, produces antibodies and activates T-cells to destroy cells with the spike protein. If the patient later catches coronavirus, antibodies and T-cells are triggered to fight the virus. The end result is very similar to that of the other vaccines.

How does the Moderna vaccine work?

This Moderna vaccine is also a mRNA vaccine like the Pfizer-BioNTech vaccine. This works by injecting a small part of the COVID-19 virus’ genetic code, which when injected enters cells and tells them to produce the coronavirus specific ‘spike protein’. The body’s immune system reacts by producing antibodies and activates T-cells to destroy the cells with the spike protein. If a patient later catches coronavirus, the antibodies and T-cells are triggered to fight the virus.. 

Why should I get the vaccine?

COVID-19 can have serious, life threatening complications and there is no way to know how you would be affected if you caught coronavirus. The vaccine is very likely to prevent you from getting COVID-19 symptoms if you are exposed to the virus, and even if you do catch the virus and display symptoms, the vaccine is extremely likely to stop them being so bad that you require a trip to hospital.

Is there any reason why someone shouldn’t get the vaccine? 

People who have had a previous serious allergic reaction to a vaccine should not have this vaccination. Pregnant women, unless they are at a high risk, should also wait until their pregnancy is over, or until the NHS guidance changes. The vaccine is being rolled out by the NHS to the highest priority groups first, so you may need to wait a while before being invited for vaccination.

More advice for women of childbearing age, those who are pregnant or breastfeeding can be found here.

Who is getting the COVID-19 vaccine first?

The Joint Committee on Vaccination and Immunisation (JCVI) has advised the Government on the groups that should be prioritised for vaccination, with those most at risk of catching coronavirus and suffering serious complications to be vaccinated first. The eligible groups for the vaccination starting with the highest priority are shown below. 

  • Older adults resident in care homes and care home workers
  • All those 80 years of age and over and frontline health and social care workers
  • All those 75 years of age and over
  • All those 70 years of age and over and those who were classed clinically extremely vulnerable
  • All those 65 years of age and over
  • People between 16-64 years of age with underlying health conditions that put them at higher risk (see conditions here)
  • All those 60 years of age and over
  • All those 55 years of age and over
  • All those 50 years of age and over

More details on the priority groups for COVID-19 vaccinations can be found here. 

How can I get a vaccine? 

The NHS will contact you and invite you to book an appointment when it is your turn to have the vaccine. This could be through a phone call from your GP practice or through an email, text message or letter. It is a good idea to make sure your GP practice has your most up to date contact information. It is important not to contact the NHS for a vaccination before they have contacted you. 

What can I expect after I have been vaccinated?

You will need to receive two doses of a vaccine to be fully protected. This will be between three and twelve weeks following your first dose and you should receive a card with the date of your next vaccination appointment. 

Once you have been vaccinated you should still continue to practice social distancing, wear a mask and wash your hands, along with following any guidance in your area. 

This guidance will continue to be updated as more information becomes available. 

More information on the Pfizer-BioNTech vaccine can be found here.

More information on the Oxford-AstraZeneca vaccine can be found here.

More information on the Moderna vaccine can be found here.