There are also types that are applied in 2 or 3 doses at intervals of months (
HPV is one of them that is administered 3 times over 12 months).
This can happen for several reasons as the virus or bacteria can evolve very fast. Thus, it is necessary to receive another dose to complete the process of antibody formation.
Some of them vaccines are offered free of charge by the Unified Health System (SUS). Private laboratories also usually sell doses of vaccines.
Some dosages can be combined – for example, tri or tetravalent – and others are applied individually.
Regardless of age or region you are in, the most important thing is to get vaccinated!
What are vaccines for?
The main function of vaccines is to immunize the organism of the recipient and thus prevent the person from being affected by the invading microorganism (bacteria or virus) when there is contact with it.
Thus, when you get vaccinated, in addition to taking care of your health, you will also be helping to fight diseases that affect society in general, such as the flu.
This is because vaccine people are immune to infections, thereby reducing the circulation of viruses. In this way, those who get vaccinated also protect other people.
In fact, some diseases (such as
Diphtheria , Measles and Poliomyelitis , also known as infantile paralysis) are already considered “very rare” in Brazil, due to the vaccination of the population.
To help the inhabitants of the country to correctly take the doses of vaccines, the Ministry of Health created the National Vaccination Calendar. Find out more about it:
National vaccination schedule
The national vaccination calendar is valid for the entire Brazilian territory. It contains vaccines that are freely available in the Unified Health System (SUS).
It is enough for the person to go to a health unit with the documents and say that they want to be vaccinated.
If she does not remember which doses she took or lost the card with this record, it is possible to check this information in the system stored on computers.
The doses present in the national vaccination calendar are divided by age group (child, adolescent, adult and elderly). Check out:
How do vaccines work in the body?
Our body has its own defense system: the immune system, which produces cells that fight invading organisms. These cells are called antibodies, which are activated when something threatens the body.
However, depending on the type of infectious agent that invades the body, the immune system can take a long time to produce cells capable of fighting infection. That’s where vaccines come in.
As the body is exposed to the causes of the disease, only in a weakened or dead way, the immune system is able to recognize and create defense mechanisms. All of this, without the risk of developing the disease.
Thus, if the person comes into contact with the active virus or bacteria (capable of transmitting the disease), the immune system will already know how to fight that intruder.
Therefore, vaccines must be received
before a person can have contact with these invaders (this is one of the reasons why babies need to get so many different vaccines, for example).
What are the types of vaccine?
To produce the vaccine, it is necessary that the virus or bacteria be prevented from transmitting the disease.
Thus, scientists modify the microorganism in laboratories so that, when they come into contact with the person’s organism, they are not strong enough and are easily combated by antibodies.
There are basically 3 ways to do this: inactivate, fragment and attenuate the agent in the vaccine formula. Like this? Calm down, the next topics explain better:
The attenuated vaccine is when the virus or bacteria present is “alive”, but weakened. This means that the microorganism, as it is more debilitated, is
not able to completely attack the patient’s body.
This wear of the infectious agent is done in laboratories, placing it in cultures of stronger and more resistant cells.
Although they are safe and effective for most people, this type of vaccine can cause symptoms similar to the disease it prevents, although it is rare.
When this happens, these symptoms are milder and have a shorter duration.
But what was explained in the previous paragraphs is valid for those who are healthy.
So, here is the warning: as the microorganism is still active, these vaccines should be applied with caution in people with immunological problems (such as multiple sclerosis).
This is because the infectious agent, even when weakened, can be harmful to the health of these patients.
Examples of attenuated vaccines are those that fight Measles, Rubella, Chickenpox and Mumps.
The inactivated vaccine is very easy to understand: it is made with the virus or bacterium inactive. This means that the infectious agents are “dead” or fragmented (into small particles).
Even so, when it comes into contact with human beings, our organism considers this intruder as dangerous and develops the necessary antibodies to fight it, making the vaccine effective.
Another positive point for inactivated vaccines is that they take only 48 hours to start taking effect. This is because, when the virus or bacteria are already inactivated (dead), they cannot reproduce and are more easily fought by the immune system.
Vaccines that fight hepatitis A and B, HPV and
rabies are examples of inactivated doses.
The fragmented vaccine is made up of the divided virus or bacteria. huh? Like this?
Scientists who produce this type of drug have the mission to divide the infectious cell body until it is no longer able to transmit the disease.
When the laboratory is able to carry out this step, then a vaccine is formulated with only a “piece” (fragment) of that microorganism.
And even if it contains only small particles of the virus or bacteria, the vaccine fulfills its main function: to stimulate the production of antibodies.
An example of a fragmented vaccine is that of the “flu” (trivalent influenza) that is offered at health clinics every year.
How are vaccines made?
Vaccines are produced in laboratories. This means that, before being applied to the population, a research and testing process is necessary to prove that that formula is effective. This can take up to 15 years.
In general, the process involves the identification of the causative agent of the disease. Numerous tests are carried out to evaluate the best composition of the vaccine, which is still in the laboratory phase.
After many studies, after the vaccine’s laboratory safety has been validated, tests on animals are started. That is, the vaccine that was tested
in vitro now goes to the in vivo evaluation .
If there is proof of efficacy and safety, after analysis, testing on humans can be initiated.
This testing phase is usually done as follows:
The vaccine is tested in a small group of healthy people (between 20 and 80 volunteers);
The tests are extended to a larger and more diverse group of people (the volunteers are of different ages and ethnicities);
Here, the vaccine’s safety is verified in volunteers belonging to the target group.
After all this process, if the results are safe and satisfactory, a “process” is opened in Organs regulatory bodies. The largest of these is the World Health Organization (WHO).
It is also necessary to have the approval of a local authority to market and apply the vaccine. In Brazil, the National Health Surveillance Agency (ANVISA) is responsible for granting this license.
Once approved, the vaccine is distributed by the laboratory to vaccination clinics. Depending on the case, the government (whether federal, state or municipal) may also be able to buy these doses to do the “mass vaccination”.
After the regulation and distribution stage, the vaccine still continues to be monitored by the manufacturer’s laboratory to estimate new side effects and thus, improve the formula more and more.
Much has been said about the
coronavirus . Unfortunately, there is still no vaccine that can help prevent the COVID-19 disease that has been plaguing the world.
But several countries are investing in laboratory research to formulate a safe and effective vaccine.
According to estimates by the World Health Organization (WHO), at least 76 surveys are already underway on all continents.
Some of these tests, in fact, are already being done on animals, which are
in vivo tests . At this rate, it is believed that this new medicine will be available by the end of 2020.
Vaccines generally take time – up to 15 years – to be distributed to the population. However, in the case of coronavirus, the whole world is in a regime called
fast track .
The main objective of this fast pace is to allow the population to have access to vaccines or medicines, even if the research phases have not ended.
In this way, laboratories are giving priority to discoveries related to the coronavirus.
As soon as one of them proves to be effective, WHO will give priority to approve it as soon as possible and distribute it to the continents, starting with the countries that are most affected by the disease.