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What is a vaccine?

Justin Hayde-West
Pharmaceutical Manager at Bupa UK
27 January 2021
Next review due January 2024
Many of us will have childhood memories of leaving the nurse’s office with a plaster on one arm and a sticker on the other following vaccinations. But what exactly is a vaccine? And how do they help to protect you from disease? Here I’ll explain. This article is about vaccine in general, but also includes some information about the COVID-19 vaccines.

What is a vaccine?

A vaccine is a medicine that aims to prevent disease. Vaccines teach your body’s immune system to recognise and fight off harmful diseases that it hasn’t come into contact with before. They’re usually given by an injection, or sometimes by mouth or a nasal spray. You might also sometimes hear injections referred to as ‘jabs’.

Is there a vaccine for COVID-19?

Yes, there are currently three vaccines for COVID-19 that have been approved for use in the UK – Oxford-AstraZeneca, Pfizer-BioNTech and Moderna.

Millions of people in the UK have received a dose of a COVID-19 vaccine since the vaccination programme began.

Who will get the COVID-19 vaccine first?

The vaccine programme is being managed through the NHS, with a set priority list to reach the most vulnerable people first. The GOV.UK website has a list of the high-priority groups.

These are thought to make up between 90-99 percent of people at risk of dying from COVID-19.

The vaccination programme will then move to the rest of the UK population, who have a lower risk of becoming ill with COVID-19.

How do vaccines work?

Vaccines help our bodies to develop immunity to the bacteria or virus that causes the disease.

When your immune system comes into contact with the weakened version of the disease, it produces antibodies in response to it. Antibodies are proteins that fight disease. If you come into contact with the disease again in future, your immune system will remember it. It will also be prepared to fight it off and protect you. This means you have developed immunity to the disease.

For example, the COVID-19 vaccines work by giving your body a set of instructions to create the antibodies and cells needed to fight off COVID-19.

Some vaccines contain a number of different germs or viruses in a single injection, so you can be vaccinated against several diseases at once. This is known as a combined vaccination. Some will require more than one dose to build immunity, while others may need a booster to bring immunity levels back up after several years. It’s safe to receive more than one vaccine at a time as your body is used to coming into contact with hundreds of germs every day. It will also reduce how many appointments you need to have.

You might experience some mild side-effects after having a vaccination. For example, your arm might feel sore if you’ve had an injection, or you might have a slight temperature. This is nothing to worry about, as your body is learning to fight the disease, and you should feel better within a few days.

Who should get a vaccine?

There are lots of different vaccines which can help protect you and those around you against many different diseases. In the UK, you’ll usually have a series of vaccinations for common diseases when you’re a baby and throughout childhood as part of the NHS childhood immunisation programme.

Other vaccinations are offered to certain groups of at-risk people as you get older. For example, the flu vaccine is recommended each year for pregnant women and people with long-term health conditions. Anyone with a weakened immune system or aged 65 or over also gets the flu vaccine.

There are some circumstances where it might not be suitable for you to have a vaccine. For example, if you’ve had an allergic reaction to one in the past – although this is rare. Your doctor or nurse will be able to let you know which vaccines are recommended for you personally.

And if you’ve missed a vaccination – it’s not too late to have one – contact your GP surgery to book an appointment.

If you’re planning a trip overseas, you might also need travel vaccinations before you go to protect you from any diseases that may be common in that country. This will depend on where you’re travelling to. Contact your travel nurse for more advice at least eight weeks before you plan to leave.

Are vaccines safe?

Vaccines are a safe and effective way to protect yourself from disease. You may have heard in the media or online that vaccines are unsafe. For example, there have been claims that the MMR vaccine is linked to Autism in children. But the evidence has shown that this isn’t the case, and the MMR vaccine does not cause Autism.

Vaccines go through extensive clinical trials and rigorous safety testing before they’re approved and made available to the public. Even then, they’re continuously monitored and reassessed by healthcare professionals to ensure they’re still safe to use.

Why are vaccinations important?

The World Health Organization (WHO) estimates that around two to three million lives are saved every year due to vaccines. If you don’t get vaccinated, you’re at a much higher risk of becoming ill with a disease – and passing it to others – if you come into contact with it. Some of these can even be fatal.

It’s especially important for babies and young children to be vaccinated early because they’re exposed to many different germs every day, but their immune systems aren’t fully developed yet.

Justin Hayde-West
Justin Hayde-West
Pharmaceutical Manager at Bupa UK

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