This page is reviewed regularly. Last updated at 12:56 on 15th October 2021.

The COVID-19 vaccine

With more and more COVID-19 vaccines being approved throughout the world and many more in clinical trials, it can be hard to keep up with what’s what. We’re keeping this page updated regularly to help you stay informed.

Information for NHS patients

If you’re a GP at Hand patient, we are your GP practice. Please see the GP at Hand vaccine information page for more details and frequently asked questions.

If you’re not a GP at Hand patient but are registered with an NHS GP, the NHS will be in contact with you via text or letter when it’s your turn to receive the vaccine.

You can now book a COVID-19 vaccine online if you are:

  • aged 18 and over
  • aged 17 and within 3 months of your 18th birthday

The following groups of people are also eligible for a COVID-19 vaccine and will be contacted by a local NHS service, such as their GP surgery, to book an appointment:

  • aged 16 and 17
  • aged 12 to 15 - most children will receive the vaccine at school, please see the NHS page for further details about eligibility
  • booster vaccines to be offered to priority groups as previously, please see the NHS page for further details

Some walk in centres are offering the COVID-19 vaccine to people aged 16 and 17 - please visit the NHS website to find out more.

Information for private patients

The COVID-19 vaccine is not available to buy privately in the UK. Babylon does not offer private COVID-19 vaccinations.

The science behind vaccination

The immune system

It’s helpful to start with a little bit about how the immune system works. Your blood contains red blood cells that deliver oxygen to the body, and white blood cells or immune cells, which fight infection.

You have many different types of specialised white blood cells. Some recognise foreign invaders, and fight them off as a first line of defence. This is called the innate immune system. The name for any foreign substance, such as such a virus, is an antigen.

You also have other white blood cells that take longer to activate, but recognise and fight specific antigens. This is called the humoral immune system. This system remembers the shape of these antigens so that if you come across that same antigen again, you can fight it off.

The main cells that protect against specific antigens and maintain this memory are B cells and T cells. B cells produce proteins called antibodies that attack the virus particles themselves. T cells attack the cells of our body that have already been infected.

How vaccines work

Generally speaking, vaccines work by helping our bodies develop immunity without being infected.

Vaccines mimic an infection. This stimulates your immune system to recognise and make a memory for the harmful antigens, without making you sick.

Sometimes after a vaccine, you may have short-lived symptoms such as a fever. This doesn’t mean you have the infection. It’s a sign that your immune system is releasing chemicals to prepare itself for what it thinks is an infection. So it’s a sign that your immune system is working.

The COVID-19 vaccine types currently approved for use in the UK

There are many different vaccines and vaccine types being produced and researched. We’ve taken a closer look at the ones currently approved for use in the UK.

1. Genetic vaccine/nucleic acid vaccine (e.g. the Spikevax (Moderna) and Pfizer/BioNtech vaccines)

    These vaccines contain genetic material - either RNA or DNA - to give your own cells instructions to make the antigen, or part of it. For COVID-19 vaccines, this is often the spike protein, which is on the surface of the virus.

    Once the RNA or DNA gets into the cell, your cells’ protein factories make the antigen that will trigger an immune response.

    The injected RNA or DNA doesn’t stay in your cells. Your cells break it down.

    T and B cells build an immunity to the newly created COVID-19 antigen. Since your own cells make the antigen, in large quantities, the immune reaction is strong.

    Both the Spikevax (Moderna) and Pfizer/BioNtech vaccines use mRNA to deliver the instructions for the COVID-19 antigen.

    The limitation of this is that mRNA is unstable and needs very cold temperatures to keep the vaccine viable.

    2. Viral Vector vaccines (e.g. the Oxford-AstraZeneca and Janssen vaccines)

    These vaccines contain a weakened version of a live, unrelated virus, called a viral vector. The vector delivers part of the target virus’s genetic material. For COVID-19, this genetic material codes for the spike protein. This is not enough of the virus to make you sick.

    Then, just as with a natural infection, your cells use the genetic code of the virus spike to make many copies of the spike protein. Your B and T cells can then mount an immune response against these.

    If you later come across the real COVID-19 virus, your immune system recognises the spike protein and is ready to fight it off.

    It’s important that the viral vector is one that not a lot of people would have been previously exposed to. If we had already been exposed to it, our immune system would attack the vaccine vector before the vaccine could work.

    In the Oxford-AstraZeneca COVID-19 vaccine, the viral vector is a version of a chimpanzee adenovirus (known as ChAdOx1).

    Viral vector vaccination mimics a real infection. But the important difference is that the target virus can’t replicate.

    Scientists have used this type of technology before in humans, such as for the Ebola vaccine.

    The vaccine is more stable than genetic vaccines, and can be stored at less extreme temperatures.

    Summary of vaccines currently approved for use in the UK


    Name: BNT162b2

    Type of vaccine: mRNA

    Number of shots: 2 doses, a minimum of 21 days apart

    How well it works: 95% effective at preventing lab-confirmed COVID-19 illness in people without evidence of previous infection.


    Name: ChAdOx1 nCoV-19 or AXD1222

    Type of vaccine: viral vector vaccine

    Number of shots: 2 shots, between 3 and 12 weeks apart

    How well it works: In analysis of over 11,000 patients in the phase 3 study, overall vaccine efficacy against symptomatic disease was 70·4%

    Spikevax (Moderna)3,4

    Name: mRNA-1273

    Type of vaccine: mRNA

    Number of shots: 2 shots, a minimum of 28 days apart

    How well it works: 94.1% effective at preventing lab-confirmed COVID-19 illness in people who received two doses who had no evidence of being previously infected.


    Name: JNJ-78436735

    Type of vaccine: Viral vector

    Number of shots: 1 shot

    How well it works: In phase 3 clinical trials with over 40,000 participants the overall vaccine efficacy against symptomatic disease was 66.3%.

    Why COVID-19 vaccination is important

    COVID-19 vaccines are approved after a team of scientific and medical experts have looked at all the trial data. This must show that the vaccines are safe and effective at preventing COVID-19. Then it can be mass-produced and distributed for external use.

    Getting vaccinated not only protects you, but also the people around you. This is particularly important for people at high risk of severe illness.

    Scientists are doing more research into the effect of vaccination on severity of illness from COVID-19. They are also researching how well it keeps people from spreading the virus to others.

    For more information on the vaccines in development, visit the WHO COVID-19 vaccine landscape.

    We’ve also answered some COVID-19 vaccine myths over on our COVID-19 vaccine myth-busting page.