Why vaccinate?

Vaccination is one of the most economical and effective methods to prevent and control infectious diseases. Vaccination can enhance the body’s immunity, improve its own resistance, resist the invasion of germs, and thus play a role in protecting the human body. Therefore, everyone will be vaccinated regularly after birth. Infectious diseases such as hepatitis B, measles, and polio are controlled through planned immunization.

Why can vaccinations prevent infectious diseases?

It turns out that the human body’s immune system has a memory function. Vaccines are also a pathogen, but they are less toxic to humans. After the human body is vaccinated, the immune system produces corresponding antibodies to fight against it, showing mild reactions, such as redness, swelling, and local ulceration. I believe people who have been vaccinated have experienced it. There are also some vaccines that hardly cause any adverse reactions after vaccination, or the reactions are too mild to be noticed.

When the immune response of the vaccine subsides, the specific antibody corresponding to the vaccine will stay in the human body for a long time, and another type of immune cell with memory function will record the information of this pathogen. When the human body encounters the same pathogen again, the existing corresponding antibodies are immediately mobilized to deal with the “enemies”, and the memory immune cells quickly call up the “files” of these “enemies” and immediately organize an effective defense response. As a result, these pathogens were controlled by the body’s defense system before the disturbance, and the disease was naturally prevented.

Egg injected with a virus for vaccine production

Inject viruses into eggs to produce vaccines

Medical vaccines and serums — Image by ? Ocean/Corbis

Vaccines and serum

Vaccines can be divided into live attenuated vaccines and inactivated vaccines according to different preparation processes. Live attenuated vaccines are prepared from non-toxic or weakly virulent strains or virus strains, such as measles vaccine. After being vaccinated with this vaccine, the attenuated strain survives and reproduces in the body, thereby stimulating the body’s immune response, which is equivalent to a natural infection process. This vaccine has a good immune effect and relatively small doses. Inactivated vaccines use artificial methods such as heating to kill pathogens, but retain their original characteristics that can cause an immune response, and can also trigger an immune response after inoculation to the human body, thereby protecting the body. With the continuous development and progress of biochemistry, molecular biology, and bioengineering technology, new vaccines are constantly emerging, such as multi-linked multivalent vaccines and DNA genetic vaccines. Multi-linked multivalent vaccines are made up of several vaccines or a mixture of vaccines and toxoids in a certain ratio. One shot can prevent multiple diseases at the same time, such as DPT vaccine and leprosy vaccine. The genetic vaccine is a vaccine prepared using DNA recombination technology, which directly integrates the pathogen’s DNA into a suitable carrier and then inoculates the human body to stimulate the human body’s immune response.

Vaccination is often called a vaccination, because injection is a common method of vaccination. But in fact, there are oral vaccination, aerosol inhalation and scratches. Different vaccination routes are not the same. If the vaccination route is not appropriate, it will not only affect the immune effect, but also may cause adverse reactions.

After vaccination, in addition to activating the body to produce the corresponding antibodies to protect its own health, sometimes it may also have an adverse effect on the body or cause allergic reactions due to the quality of the vaccine itself, which we call side effects of vaccination. Common side effects of vaccination include general reactions and abnormal reactions. General reactions are local or systemic allergic reactions caused by the characteristics of biological products, such as local redness, fever, nausea, vomiting, etc.; abnormal reactions refer to reactions that require medical treatment and treatment after vaccination.

In order to prevent the occurrence of abnormal reactions, the World Health Organization (WHO) has made regulations for immunization of certain populations or certain situations: patients with abnormal immune function (such as immunodeficiency, malignant diseases) cannot use live vaccines; immune preparations are being used Patients who are treated should not be vaccinated with live vaccines; children with obvious symptoms of general discomfort, such as fever, need to postpone their vaccination; vaccines that require continuous multiple doses of vaccination, if allergies or other serious adverse reactions occurred during the previous vaccination, the other should be cancelled Vaccination of shots; people with allergies should use the vaccine with caution.

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