General Practice 2022

Vaccines: what they are, types and what they are for

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Vaccines: what they are, types and what they are for
Vaccines: what they are, types and what they are for

Vaccines are substances produced in the laboratory whose main function is to train the immune system against different types of infections, as they stimulate the production of antibodies, which are substances produced by the body to fight invading microorganisms. Thus, the body develops antibodies before coming into contact with the microorganism, leaving it ready to act more quickly when that happens.

Although most vaccines need to be given by injection, there are also vaccines that can be given orally, such as OPV, which is the oral polio vaccine.

In addition to preparing the body to respond to an infection, vaccination also reduces the intensity of symptoms and protects everyone in the community, as it reduces the risk of disease transmission. Check out 6 good reasons to vaccinate and keep your booklet up to date.

Types of vaccine

Vaccines can be classified into two main types, depending on their composition:

  • Attenuated microorganism vaccines: the microorganism responsible for the disease undergoes a series of procedures in the laboratory that decrease its activity. Thus, when the vaccine is administered, an immune response against this microorganism is stimulated, but the disease does not develop, as the microorganism is weakened. Examples of these vaccines are the BCG, MMR and chickenpox vaccine;
  • Vaccines with inactivated or dead microorganisms: contain microorganisms, or fragments of these microorganisms, that are not alive stimulating the body's response, as is the case with the vaccine for hepatitis and meningococcal vaccine.

From the moment the vaccine is administered, the immune system acts directly on the microorganism, or its fragments, promoting the production of specific antibodies.If in the future the person comes into contact with the infectious agent, the immune system can already fight and prevent the development of the disease.

How vaccines are made

Producing vaccines and making them available to the entire population is a complex process that involves a series of steps, so the manufacture of vaccines can take between months to several years.

The most important phases of the vaccine creation process are:

Phase 1

An experimental vaccine is created and tested with fragments of the killed, inactivated or attenuated microorganism or infectious agent in a small number of people and then the body's reaction is observed after the vaccine is administered and development of side effects.

This first phase lasts an average of 2 years and if there are satisfactory results, the vaccine moves on to the 2nd phase.

Phase 2

The same vaccine is tested on a larger number of people, for example 1000 people, and in addition to observing how your body reacts and the side effects that occur, we try to find out if different doses are effective, the in order to find the right dose, which has the least harmful effects, but which is able to protect all people, all over the world.

Phase 3:

Assuming that the same vaccine has been successful until phase 2, it moves on to the third phase which consists of applying this vaccine to a greater number of people, for example 5000, and observing if they are really protected or not.

However, even with the vaccine in the last phase of testing, it is important that the person adopts the same precautions related to protection against contamination by the infectious agent responsible for the disease in question. Thus, if the vaccine being tested is against HIV, for example, it is important that the person continues to use condoms and avoid sharing syringes.

National vaccination schedule

There are vaccines that are part of the national vaccination plan, which are administered free of charge, and others that can be administered on medical advice or if the person travels to places where there is a risk of contracting an infectious disease.

Vaccines that are part of the national vaccination plan and that can be administered free of charge include:

1. Babies up to 9 months

In babies up to 9 months of age, the main vaccines in the vaccination plan are:

At birth 2 months 3 months 4 months 5 months 6 months 9 months



Single dose
Hepatitis B 1st dose 2nd dose 3rd dose

Pentavalent (DTPa)

Diphtheria, tetanus, whooping cough, Hepatitis B and Haemophilus influenzae meningitis b

1st Dose 2nd Dose 3rd Dose



1st Dose (with VIP) 2nd Dose (with VIP) 3rd Dose (with VIP)

Pneumococcal 10V

Invasive diseases and acute otitis media caused by Streptococcus pneumoniae

1st Dose 2nd Dose



1st Dose 2nd Dose

Meningococcal C

Meningococcal infection, including meningitis

1st Dose 2nd Dose
Yellow Fever 1st dose
Haemophilus influenzae b 1st dose 2nd dose 3rd dose

2. Children between 1 and 9 years old

In children between 1 and 9 years old, the main vaccines indicated in the vaccination plan are:

12 months 15 months 4 years - 5 years 9 years

Triple bacterial (DTPa)

Diphtheria, tetanus and whooping cough

1st Booster (with DTP) 2nd Boost (with DTP)



1st Booster (with VOP) 2nd Boost (with VOP)

Pneumococcal 10V

Invasive diseases and acute otitis media caused by Streptococcus pneumoniae


Meningococcal C

Meningococcal infection, including meningitis

1st Reinforcement 2nd booster

Triplice viral

Measles, mumps, rubella

1st dose
Chickenpox 2nd Dose
Hepatitis A Single dose

Viral tetra

Measles, Mumps, Rubella and Chickenpox

Single dose


Human papilloma virus

2 servings (9-14 year olds)
Yellow Fever Reinforcement 1 Dose (for non-vaccinated)
Haemophilus influenzae b Reinforcement

3. Adults and children from 10 years old

In adolescents, adults, elderly and pregnant women, vaccines are usually indicated when the vaccination schedule was not followed during childhood. Thus, the main vaccines indicated during this period are:

10 at 19 years Adults (20 to 59 years old) Elderly (> 60 years old) Pregnant

Hepatitis B

Indicated when there was no vaccination between 0 and 6 months

3 doses 3 doses (depending on vaccination status) 3 doses 3 doses

Meningococcal ACWY

Neisseria meningitidis

1 Dose (11 to 12 years)
Yellow Fever 1 Dose (for non-vaccinated) 1 dose

Triplice viral

Measles, mumps, rubella

Indicated when there was no vaccination up to 15 months

2 Servings (up to 29 years old) 2 doses (up to 29 years old) or 1 dose (between 30 and 59 years old)

Adult duo

Diphtheria and tetanus

3 doses (and booster every 10 years) Reinforcement every 10 years Reinforcement every 10 years 2 Servings


Human papilloma virus

2 Servings

dTpa adult

Diphtheria, tetanus and whooping cough

1 Dose He althcare professionals (1 dose + booster every 10 years) Single dose in each pregnancy

Watch the following video and understand why vaccination is so important:

Frequently asked questions about vaccines

1. Does vaccine protection last a lifetime?

In some cases, the immunological memory lasts a lifetime, however, in others, it is necessary to have a booster of the vaccine, as is the case of meningococcal disease, diphtheria or tetanus, for example.

It is also important to know that the vaccine takes some time to take effect and, therefore, if the person is infected shortly after taking it, the vaccine may not be effective and the person may develop the disease.

2. Can vaccines be used in pregnancy?

Yes. As they are a risk group, pregnant women should take some vaccines, such as the flu, hepatitis B, diphtheria, tetanus and whooping cough vaccine, which are used to protect the pregnant woman and the baby. Administration of other vaccines should be evaluated on a case-by-case basis and prescribed by the physician. See which vaccines are recommended during pregnancy.

3. Do vaccines cause some people to faint?

No. Generally, people who pass out after receiving a vaccine are because they are afraid of the needle, because they feel pain and panic.

4. Can breastfeeding women be vaccinated?

Yes. Vaccines can be given to lactating women, in order to prevent the mother from transmitting viruses or bacteria to the baby, however it is important that the woman has the guidance of the doctor. The only vaccines contraindicated for women who are breastfeeding are yellow fever and dengue.

5. Can more than one vaccine be taken at the same time?

Yes. The administration of more than one vaccine at the same time does not harm he alth.

6. What are combination vaccines?

Combined vaccines are those that protect the person from more than one disease and in which only one injection is required, as is the case of the triple viral, tetraviral or bacterial penta, for example.

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