How Do Vaccines Work? – A Detailed Guide

How do vaccines work? In a world dealing with infectious diseases, this question is crucial for our health. Vaccines, seen as modern medical marvels, play a big role in keeping us safe from viruses and bacteria.

Here’s the brief: Vaccines are one of the most important tools we have to protect ourselves and our communities from infectious diseases. They work by teaching our immune system how to recognise and fight off specific viruses or bacteria without us actually having to get sick.

In this blog, we will delve into the intricacies of how vaccines work, their importance, and safety measures.

What is a Vaccine?

So, let’s first define vaccination. Imagine your body is like a castle, and germs are like invaders trying to get in and make you sick. A vaccine is like a training exercise for your body’s defence system (your immune system).

The vaccine shows your immune system a weakened or harmless version of the germ, like a training dummy for the real invader. This way, your immune system can learn to recognise and fight off the real germ if you ever come across it.

Think of it like showing a picture of a robber to your castle guards. They’ll learn what the robber looks like and be ready to stop them if they ever try to break in. Vaccines work in a similar way, but instead of pictures, they use a weakened version of the germ itself to train your immune system.

How Are Vaccines Made?

To create vaccines, the initial step involves generating the organism, known as the pathogen, responsible for causing the disease. This pathogen can be a virus or bacterium, and they are cultivated in large quantities within a laboratory by infecting cells in tissue culture.

The next crucial step is modifying the pathogen to ensure it doesn’t trigger the disease itself. This modification can be achieved through the following methods:

• Weakening or “attenuating” the pathogen by growing it repeatedly, selecting a less dangerous strain. For instance, MMR vaccines employ this weakened form.
• Extracting the part of the pathogen that causes the immune response and incorporating it into the vaccine. The Hib vaccine is produced using this method.
• Inactivating the toxin produced by the pathogen. This is how the tetanus vaccine is manufactured.

The treated pathogen is then combined with additional ingredients, such as stabilisers and preservatives, to formulate a vaccine dose. This carefully crafted process ensures that the vaccine stimulates the immune system to fight the disease without causing illness.

Importance of Vaccination

So, what do vaccines do? Vaccination is super important for keeping us and our kids healthy. It stops dangerous diseases that used to hurt or kill many people, like smallpox and polio. Thanks to vaccines, these diseases are rare now. But if we stop getting vaccines, these sicknesses can come back fast. The World Health Organization says that not wanting vaccines (vaccine hesitancy) is a big problem for everyone’s health.

In England, we’re seeing measles and mumps again, even though the MMR vaccine is the best protection. Measles can be really serious, causing meningitis, and mumps can make you lose your hearing.

Here’s a key thing: if 95% of kids get the MMR vaccine, we can stop measles from spreading completely. But if less than 90% of people get vaccinated, measles, mumps, and rubella can quickly come back.

As of February 1, 2024, according to a news report, more people are getting sick with norovirus and flu in winter, putting extra pressure on the NHS. This emphasises how important it is to get vaccinated against flu and COVID-19 to help ease the strain on healthcare.

So, it’s important for everyone to get their routine vaccinations to stay protected. Vaccines not only keep us safe but also help our whole community. When many people get vaccinated, it’s tough for diseases to spread, especially to those who can’t get vaccines because they’re sick or have a weak immune system. It’s like creating a shield for everyone!

The Role of Vaccines in Disease Reduction

Vaccines undergo meticulous safety testing before introduction, ensuring they are both effective and safe. The elimination or reduction of diseases, like measles and diphtheria, has been directly linked to widespread vaccination. This preventative measure not only shields individuals but also contributes to the concept of herd immunity, protecting those who cannot receive vaccines.

How Do Vaccines Work?

Here’s a breakdown of how vaccines work:

Mimicking an Infection

Vaccines contain a weakened or inactive form of a virus or bacteria, or a small part of it, called an antigen. When we receive a vaccine, our immune system sees the antigen as a foreign invader and triggers an immune response.

Immune response

Our body’s white blood cells recognise the antigen and produce antibodies, which are proteins specifically designed to fight that particular antigen. These antibodies circulate in our bloodstream, ready to attack the virus or bacteria if we encounter it in the future.

Long-term protection

Once our immune system has produced antibodies and “learned” to fight the antigen, it remembers the specific characteristics of that virus or bacteria. This creates long-term immunity, meaning that if we come into contact with a real virus or bacteria in the future, our immune system can quickly respond and destroy it before we get sick.

Newborn babies are born with some protection against diseases like measles, mumps, and rubella. This protection comes from their moms through a special connection called the placenta. It’s like a shield, but it only lasts a short time, maybe a few weeks or months. For measles, mumps, and rubella, this shield might stay for about a year. That’s why babies get the MMR shot when they turn one – to keep them safe!

Types of Vaccines

There are different types of vaccines, but they all work on the same principle of stimulating the immune system to produce antibodies. Here are some common types:

Inactivated Vaccines

• These vaccines contain a dead version of the germ that causes a disease.
• They might need multiple doses over time to give ongoing protection.
• Examples: Hepatitis A, Flu, Polio, Rabies.

Live-Attenuated Vaccines

• These types of vaccines contain a weakened form of the germ, causing the disease.
• They create a strong and long-lasting immune response.
• Limitations include precautions for people with weakened immune systems.
• Examples: Measles, Mumps, Rubella (MMR), Rotavirus, Smallpox, Chickenpox, Yellow fever.

mRNA Vaccines

• These vaccines, like some COVID-19 vaccines, use mRNA to trigger an immune response.
• They have benefits such as shorter manufacturing times and no risk of causing the disease.
• Example: COVID-19.

Subunit, Recombinant, Polysaccharide, and Conjugate Vaccines

• These vaccines use specific components of the germ, like proteins or sugars, to create a strong and targeted immune response.
• They are suitable for a broad range of people, including those with weakened immune systems.
• Booster vaccine shots may be needed for ongoing protection.
• Examples: Hib disease, Hepatitis B, HPV, Whooping cough, etc.

Toxoid Vaccines

• These vaccines use a toxin produced by the germ, causing the disease.
• They create immunity to the harmful parts of the germ rather than the germ itself.
• Booster vaccine shots may be required for continuous protection.
• Examples: Diphtheria, Tetanus.

Viral Vector Vaccines

• These vaccines use a modified version of a different virus to deliver protection.
• Viruses like influenza, measles, or adenovirus (common cold virus) act as vectors.
• Examples: COVID-19 (some vaccines studied in clinical trials).

Vaccine Safety

Contrary to misconceptions, vaccines undergo rigorous testing over several years before approval for public use. Once a vaccine is being used in the UK, it’s watched closely for any uncommon side effects by a group called the Medicines and Healthcare Products Regulatory Agency (MHRA). They also keep a close eye on whether the vaccine still does its job properly. The little discomfort or a sore arm after a shot is nothing compared to getting really sick from preventable diseases.

Who Can Not Have Vaccines

Not many people can’t get vaccines – it’s usually those who have had a bad allergic reaction before or are allergic to vaccine ingredients. Also, if your immune system is not strong, like during cancer treatment, some vaccines might not be suitable.

If you’re unsure whether you or your child can get a vaccine, ask your doctor, nurse, or pharmacist.

Side Effects of Vaccination

Now, let’s talk about side effects – most are mild and don’t last long. The common ones are a bit of redness and swelling where the needle went in, feeling a bit unwell, or having a high temperature for a day or two. Some older kids or adults might feel a bit dizzy or tired and get a headache, mild fever, or flu-like symptoms.

And hey, it’s okay if a child cries after a shot – it’s normal, and they’ll feel better with a little cuddle. Serious allergic reactions are super rare, and if they happen, the person giving the shot knows how to handle it and will treat it right away. So, you or your child will recover well with quick treatment!

FAQs

What does a vaccine contain?

Vaccines hold weakened or inactive parts of a germ (antigen), leading the body to respond. Newer vaccines carry instructions for creating antigens, not the actual germ components.

Are vaccines safe?

Vaccines are safe, but, like any medicine, they may have some side effects. These are typically minor and short-lived, like a sore arm or mild fever. Serious side effects are rare but possible.

What happens if you get 4 doses of Covid vaccine?

Getting a fourth dose of a COVID vaccine, specifically an mRNA vaccine, is safe and increases antibody levels, surpassing those achieved with a third dose, according to the latest vaccine news from the COV-BOOST trial led by University Hospital Southampton. The results are published in The Lancet Infectious Diseases.

Do I need Covid vaccine to travel?

Yes, if you are travelling to a country that requires proof of COVID-19 vaccination or mandates quarantine for individuals not fully vaccinated, it is advisable to contact your local healthcare provider to ensure you meet the travel vaccination requirements.

How to get vaccinated in the UK?

To get vaccinated in the UK, contact your local GP or vaccination centre or use the National Booking Service to schedule an appointment for your vaccination. Walk-in options may also be available at certain locations.

Can you overload a child’s immune system?

No, vaccines don’t overload a child’s immune system; studies confirm they strengthen it. Babies naturally encounter more germs daily, and the weakened viruses in vaccines are minimal compared to natural exposure.

How long does a vaccination last?

The duration of vaccination protection varies; MMR can offer 90% protection after one dose, while some, like the typhoid vaccine, provide around 70% protection over three years.

Wrapping Up

To sum it up, learning “How Do Vaccines Work?” reveals the amazing protection they provide against illnesses. Vaccines, a marvel of modern medicine, help our immune system protect people and communities, stressing their crucial role in maintaining worldwide health.