Vaccines are substances that aim to stimulate the immune system, so that when we have contact with a certain pathogen, O our body be prepared to protect us faster and more efficiently. Vaccines are made using antigens, which are molecules that react with a antibody. These antigens can be dead, attenuated infectious agents, or a part of these agents. Vaccines can be given orally or through injections.
Read more: History of the vaccine - began with the creation of the smallpox vaccine
What are vaccines and how are they made?
Vaccines are substances traditionally made usingif attenuated, dead disease-causing organisms or even some of their derivatives. These components of vaccines are known as antigens. In addition to antigens, vaccines have other components, which maintain their effectiveness, prevent the proliferation of microorganisms and preserve them.
Among the components that we can find in vaccines, we can mention saline, stabilizers, preservatives, egg protein (material used for the growth of the infectious agent), immune response enhancers (adjuvants), and antibiotics. It is important to know the composition of the vaccine, as some people have allergy to certain components.
How do vaccines work?
When applied, the vaccine makes our bodies work the same way as when we contract the disease. Our body recognizes the antigen and fights it through an immune response. Our immune system is responsible for producing proteins called antibodies, which act in the body's defense.
In addition, the immune system produces cells able to ensure that the body has a faster and more effective response, if the body is exposed again to that agent. As the vaccine is not capable of causing the disease, the immune system provides our protection without our body taking risks inherent to it.
Can vaccines be harmful to health?
First of all, it is important to emphasize that vaccines save many lives, preventing serious diseases from affecting our bodies and ensuring that epidemics are controlled. At vaccines currently available to the population are safe, and all passed rigorous testing before being released by regulatory agencies.
Many feel insecure about getting vaccinated due to reports that some people have experienced side effects. However, side effects are observed in the use of any medication., and serious complications are usually the exception. when it comes to vaccination. Among the main side effects seen in people after using vaccines are: pain, redness at the injection site and fever.
Some situations, however, deserve more attention. Immunosuppressed and pregnant women, for example, cannot receive any vaccine. So it's important to talk to the doctor on the relationship between risks and benefits of vaccination.
Read too: 5 myths about vaccines
What is the difference between serum and vaccine?
THE vaccine is considered a type of active immunization, as it stimulates our body to produce antibodies against a certain agent. Vaccines are used as a form of prevention. O serum, in turn, does not stimulate our immune system, being known as a passive immunization.
In the case of serums, the causative agent of the disease is inoculated into an animal, such as a horse, so that it produces antibodies. Afterwards, the blood is taken from that animal, and the antibodies are obtained from the plasma. When we receive serum, therefore, we are receiving ready-made antibodies. The serum is not used as a form of prevention, but as a treatment. To learn more about the characteristics and differences between these substances, read our text: Serum and vaccine.
What is the role of vaccines?
Vaccines are intended to induce an immune response of the organism. The purpose of inducing the immunity it is to guarantee protection against a certain disease or prevent it from developing in a severe way.
We cannot think, however, that the vaccine has only individual benefits. Vaccination protects the individual against a certain disease but also ensures that the circulation of a certain agent in the population decreases. If more people are protected, fewer cases of the disease are diagnosed, bringing benefits to the health system and even to the economy of a country.
In some cases it is It is possible to completely eliminate a disease with the application of vaccines. in the population. This is the case of smallpox, which was declared eradicated worldwide on May 8, 1980. In Brazil, as well as in various parts of the world, the polio it has also been eradicated thanks to major vaccination efforts. Brazil received the poliomyelitis elimination certificate in 1994. Worldwide, only Pakistan and Afghanistan still register cases of this disease.
Read too: The importance of vaccination
Some diseases for which vaccines already exist
The flu: is a disease that affects the respiratory system and is caused by virus influenza. There are four types of influenza viruses: A, B, C and D. Types A and B are responsible for seasonal epidemics. These viruses suffer constant mutations, and therefore, every year, the vaccine is reformulated. so it is important to get vaccinated annually against the flu.
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Covid-19: is an infectious disease caused by the Sars-CoV-2 virus. Among its main symptoms, we can mention fever, tiredness and dry cough. covid-19 had its first cases identified in 2019, and, in 2020, it was recognized as a pandemic.
Covid-19 was responsible for thousands of deaths worldwide, prompting laboratories in several countries to quickly begin the search for an effective vaccine. On January 17, 2021, Anvisa authorized in Brazil the emergency use of two vaccines against the covid-19, and the first person was vaccinated, marking the beginning of the population's vaccination against the disease.
Measles: it is a potentially fatal viral disease that presents symptoms such as fever, cough, eye irritation, malaise and body spots. The vaccines that protect against measles, according to the Ministry of Health, are the double viral, the triple viral and the tetra viral. The viral duo protects against measles and rubella. The triple protects against measles, mumps and rubella. Finally, tetra viral protects against measles, mumps, rubella and chickenpox.
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Tetanus: is a disease caused by bacteriumClostridium tetani. Accidental tetanus usually occurs when a person suffers skin damage from objects left in the environment and contaminated by the bacteria. Symptoms include muscle contraction, stiff limbs, and difficulty opening your mouth.
Neonatal tetanus, in turn, is contracted by contamination of the umbilical stump by bacterial spores which may be in instruments that are not properly sterilized or in products used in the dressing umbilical. In neonatal tetanus, symptoms include difficulty opening the mouth and suckling, excessive crying, muscle contraction, and irritability. Accidental tetanus is prevented through vaccination. In the case of neonatal tetanus, the newborn's immunity is achieved thanks to the adequate vaccination of the mother.
Yellow fever: is a disease caused by a virus and transmitted by mosquito vectors. Urban yellow fever has the mosquito as a vector Aedes aegypti, popularly known as dengue mosquito. This disease causes symptoms such as fever, chills, body aches, headache, nausea and vomiting. It can also cause jaundice in more severe cases. Jaundice can be defined as a yellowish discoloration of the skin and eyes.
Polio: also known as infantile paralysis, it is a disease caused by poliovirus. Transmission occurs mainly via the oral-faecal route. Polio can trigger paralysis and even death. In some situations, however, the disease may be asymptomatic. Although Brazil received the polio elimination certificate in 1994, vaccination is still important, as that the disease continues to occur in some parts of the world, and non-vaccination can cause it to return to our parents.
By Vanessa Sardinha dos Santos
Biology teacher
