Inici 8-12 years What is a vaccine?

What is a vaccine?

by escoles_admin

germenbo_cA vaccine is a preparation that causes your body to produce antibodies which will make you immune to a disease.

Antibodies? Immune? Maybe you don’t know what these words mean. Well, it’s easy. An antibody is a defensive substance created by the body when it comes across cells from a different body, and to be immune means to be free of something, to succeed in not letting it affect you.

To be vaccinated means “to take precautions” against a disease; in other words, to prepare our body so that it can stand up to infectious disease and overcome the viruses and bacteria that cause it.

Vaccines are made from germs that can cause the disease, and their job is to get our body’s natural defences working to protect us against the infection.

It’s as if you were training your body to always be on the alert against a particular disease.

Why do we have to be vaccinated?

Young babies and small children are more delicate than grown-ups and can fall ill more easily. That’s why they need to be vaccinated. Generally, by the time they are two years old, they’ve already been vaccinated against a number of diseases.

Being vaccinated has individual and social benefits, in other words it’s good for you, and it’s also good for everyone else around you and near you.

Origin of vaccines

On 14th May 1796, an English doctor called Edward Jenner was the first to inoculate (which means to introduce into the body by means of a syringe) a vaccine against smallpox. The patient was an eight-year-old boy called James Phipps..

The doctor took some infectious fluid from the wound of a milkmaid who had caught cowpox when milking a cow.
Two weeks later, he again inoculated James with some pus he had taken from a smallpox patient. The boy never showed any signs of smallpox infection, and this proved that inoculating the germ – or, in other words, vaccinating – provokes a defence reaction by the body.

Jenner Jenner did not have an easy time: many doctors thought his idea was no good, but they were later silenced by his results.
Of course, vaccines have changed over the years. Their side-effects have been mitigated and their doses reduced, but the basic idea behind them has not changed a bit.

Jenner vaccinated the poor people in his town, Berkeley, and the surrounding district, free of charge. Many of those he vaccinated had been staunch opponents of vaccination, but the local vicar advised everyone to go and see the doctor because he was fed up with holding funerals for people who, if only they’d been vaccinated, would not have died of smallpox.

Nowadays, this vaccine is regarded as just another discovery, but you should know that in those days, some 15,000 people a year were dying of smallpox in France; in Germany over 70,000 people were affected, and in Russia, smallpox killed 2 million people in just one year.

Diseases we need to be vaccinated against

The most important children’s diseases that can be avoided through vaccination are:

The polio virus causes severe muscular problems which can lead to muscle paralysis (the muscles stop working). Many polio sufferers used to end up in a wheelchair, or even die. Nowadays, extensive vaccination is responsible for preventing the few instances of this disease from spreading.

A disease characterised by the formation of plaques in the throat which make it difficult to swallow and breathe. It often causes heart and nerve problems. About 10% of those affected die, 20% in the case of children or elderly people. In some parts of the world, like Eastern Europe, there are still cases of diphtheria owing to insufficient vaccination.

Whooping cough
A disease affecting the respiratory tract, characterised by causing so much coughing that it is difficult to eat, drink or even breathe. The frequent vomiting leads to weight loss. In children the disease can also lead to pneumonia and brain disorders. Without vaccination, this disease would be a lot more prevalent.

A disease caused by a bacterium that enters the body via cuts and wounds and attacks the nervous system. It causes a very high fever and very painful muscle spasms. It is often a serious disease. The mortality rate for tetanus can reach over 50%. It’s a good idea to be vaccinated because the tetanus bacterium spreads easily in earth and dust.

This is a highly contagious disease. Its symptoms are: coughing, high fever, watery eyes, sneezing and a rash of small red spots all over the body. Between the 1950s and 60s, almost everyone had measles at some time or another. Over 20% were hospitalised, and 7% suffered complications such as pneumonia, diarrhoea or ear infections. Less frequently, there were also a few cases of encephalitis and death. As measles is highly contagious, without vaccination it would spread very rapidly.

This disease causes severe inflammation of the meninges, that is, the membranes sheathing the brain and the nerves.
Meningitis used to affect a large number of children and could have important sequelae such as encephalitis, paralysis and neuronal disorders. An effective vaccine was not available until recently. Now, however, the vaccine gives a great deal of protection, which is why it is now included in the vaccination calendar.

An infectious disease causing inflammation of the liver and lesions that increasingly impair its functioning. People with hepatitis B are at high risk of the infection becoming chronic and eventually causing cirrhosis and cancer of the liver. Vaccination is recommended and, at present, evidence suggests that the number of cases of this disease have diminished a great deal.

Rubella (German measles)
The rubella virus causes a rash of small red spots on the skin and palate. If a pregnant woman gets rubella during the first three months of her pregnancy, the baby may develop congenital rubella syndrome, involving heart lesions, cataracts, mental retardation and deafness. Now, however, thanks to extensive vaccination, there are hardly any cases of congenital rubella syndrome.

In this disease the parotid gland, the largest salivary gland in the body, located near the jaw, becomes inflamed and swollen. Before vaccination, this disease frequently caused deafness in children. It wasn’t usually a very serious disease but in some cases it could lead to nerve and brain problems, ending in paralysis. It also increased the possibility of miscarriage during the first three months of pregnancy. As it is a highly contagious disease, without vaccination it would very easily spread among those not vaccinated.

Another vaccine that is also used frequently for elderly people or people with respiratory problems, is the flu vaccine.
Other vaccines are necessary when you’re travelling to countries affected by endemic diseases that are not prevalent in Europe.

When you’re going to be vaccinated

When you’re going to be vaccinated, think of it as something that will prevent you from getting ill. Yes, the needle-jab might hurt a bit, but it’s only a second of pain, for a lifetime of health.

Did you know that there are lots of children in the world who cannot be vaccinated? Maybe you cut yourself one day and were told you had to have an anti-tet jab. Don’t worry, there’s no need to be scared!!

Other effects

Vaccination began over a century ago, and in many countries it has been almost obligatory for 60 years.

Some vaccines have side-effects.

Vaccines are safe, but sometimes they can be a bit painful at the jab site, or cause a mild fever or an allergic reaction.

However, these side-effects are always better than having the actual disease.

Some people think that vaccines are not necessary. They’re wrong. It’s very difficult for someone never to come into contact with any disease and, if they haven’t been vaccinated, they can get infected..

How many types of vaccine are there?

Research has made it possible to create combined vaccines, meaning that a single vaccine will vaccinate you against several different diseases

The advantage is that only one jab is needed.



In 1918, a flu epidemic – which was christened “Spanish flu“- caused the death of over 50 million people worldwide. Now, with the vaccine, this can be avoided.

Present day

At present, lots of scientists are trying to find a vaccine against diseases such as aids and malaria, which affect millions of people throughout the world and are endemic in many places in Africa.


Author: M. Pilar Gascón. Pharmacist.


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