How do vaccines work?

June 2023

How do meningitis vaccines work?

Meningitis vaccines have helped to save millions of lives worldwide by working with our bodies natural defences to develop protection against the most common causes of the disease.

So, what causes us to become ill and how exactly do meningitis vaccines work?

Germs can be found everywhere. At any time, there are trillions of bacteria and viruses both on and inside the body. Not all cause disease and most won’t make us ill because our immune systems are designed to protect us.

How? Over time, as we grow, our bodies learn to recognise bugs that cause disease (such as bacteria, viruses, fungi or parasites) by using the antigens on the surfaces of the cell (which consists of largely proteins and sugars) to recognise if germs pose a threat. 

Any harmful bugs that are detected trigger the body’s immune system. The body responds by producing antibodies. These provide protection for the body by sticking to harmful bugs, killing and disabling them.

Why are the bacteria that cause meningitis and septicaemia so dangerous?

The bacteria that cause diseases like meningitis and septicaemia, are particularly dangerous – because of the speed in which they can kill. When they invade the body, they can multiply rapidly. This leaves the immune system very little time to produce the protective antibodies it needs. If the immune response is too slow it could potentially be fatal.

Vaccines are important because they play a critical role in the bodies response to the bacteria by working with the body’s natural defences to speed up our natural immune response.

How exactly do meningitis vaccines work?

Meningitis immunisations work by introducing antigens: small, harmless amounts or fragments from the bugs that cause disease which are dead, weakened or inactive, into your system. Our immune system uses the antigens on the cell’s surface to remember the bugs and develop protective antibodies against them. 

How does this help? If you’ve been vaccinated, and your body meets the same bugs that can cause meningitis, which were in your vaccine, your immune system can react immediately, as it will already have the antibodies it needs to destroy the bacteria before they can make you unwell.

Vaccination schedules are designed so that we get vaccinated at times in life when we are more likely to be exposed to the harmful bacteria that can cause meningitis. So it’s vital to ensure that you and your family take up the immunisations available to you at the right time without delay.

Are meningitis vaccines safe?

Yes. Vaccines are thoroughly tested and are the safest way to develop protection against some of the most common causes of deadly diseases like meningitis.

As with all medication, vaccines can cause some side effects, such as soreness/redness for some people around the area of injection, but any vaccine that is given to a child or adult is rigorously tested and monitored for safety, to ensure that the benefits outweigh any risk.

The overwhelming evidence shows that vaccinating is safer than not vaccinating. For example, between 2000 and 2023 Hib and pneumococcal vaccines have been estimated to have saved nearly 4 million lives across 112 low and middle income countries. The monitoring of vaccine safety alongside the administration of millions of doses of these vaccines worldwide has generated lots of evidence about how safe these vaccines are.

Can vaccines protect against all causes of meningitis?

There are safe and effective vaccines available that protect against the most common causes of life-threatening bacterial meningitis and septicaemia - meningococcal, pneumococcal and Hib. These are routinely available in many different parts of the world and have saved millions of lives

However, there are many different causes of meningitis and septicaemia and not all are vaccine preventable. That is why it’s always important to remain aware of the signs and symptoms – even if you have had all the vaccines available to you.

Why don’t some people get vaccinated?

Despite their safety and their success, some people don’t always get the vaccines that are available to them.

This could be for several reasons, such as access to vaccines, which is not equal across the world, with meningitis disproportionally affecting the poorest communities in the world.

Other reasons include misunderstanding around the safety of vaccines, the inconvenience of getting to a medical centre or appointment, or a lack of awareness of the disease. Vaccines have been so successful in reducing disease to such low levels that some causes of meningitis, such as Hib and MenC, are rarely seen in some parts of the world. It’s critical to get the vaccines that are available to you on time so you can protect yourself and everyone you care about against deadly infections like meningitis.

Questions?

Questions?

If you have questions or concerns about vaccines, our support team can help.
Since the charity was founded in 1989, we have awarded 161 research grants. The total value of our investment in vital scientific research is over £19.1 million (€24.7 million).
You don’t need to face meningitis and sepsis alone
A global vision for meningitis by 2030 and an action plan to get there.