What is a vaccine (vaccine)? Why is the vaccine not used to treat illness but to prevent it?

Although the term vaccine (vaccine) is widely used, everyone has been vaccinated, but there are still many people misunderstand about the vaccine, saying that the vaccine is used to treat diseases, when in fact this is a preparation Used to prevent disease for healthy people.

What is a vaccine?

Vaccine (also called a vaccine) is an antigen-derived preparation derived from a pathogenic microorganism or an organism with an antigen-like structure similar to a pathogenic microorganism, which has been formulated to ensure safety. It is absolutely necessary for the use of a healthy human body and to create a specific immune status that actively proactively fights off the pathogen.

Vaccines contain weakened or virus-like versions of the virus, usually those living or attenuated or killed, called antigens . Antigens are unable to produce signs or symptoms of the disease. When introduced into the body, the body recognizes it as a "foreign object", stimulating the immune system to produce neutralizing antibodies. The cause of the disease, like a natural infection. The process of making antibodies usually takes a few weeks, which can cause mild symptoms such as fever. But this is a normal manifestation and is considered a sign of the body's immune response. After this "mimic" infection process is finished, the body will produce lymphocytes with immune memory, ready to respond quickly when meeting pathogens in the following times, helping muscles. Be proactive against the pathogen when exposed to future viruses.

Vaccines often take a long time to research and test.

It can be said that the invention of the enner scientist in 1796 was a great medical achievement for mankind. Since the inception of the vaccine, mankind has truly had the highest, sharpest and most effective weapon to actively prevent dangerous infectious diseases.

Vaccines often take a long time to research and test. When a new vaccine is developed, it is necessary to undergo animal testing, then a small group of people and then it can be used in the community. These test steps help ensure the safety and ensure the vaccine's effectiveness. Human-based vaccine testing is often quite expensive and research units will need to recruit volunteers to participate in the trial.

The use of vaccines

Vaccines help improve the body's resistance to diseases. When vaccinated, the body's immune system recognizes vaccines as foreign objects that destroy and remember them, thereby creating immune memory. Later, when a true pathogen enters the body, the immune system will attack the pathogen quickly and effectively to protect the body against the disease.

Thanks to the vaccine millions of children do not die from infectious diseases. People who have been vaccinated will not get the disease or sequelae caused by the disease.

When the vaccination program is working well, most people are vaccinated against a disease, sometimes the disease can disappear completely from the community and the vaccination program may stop. For example smallpox. However, for some diseases such as measles, if the program is stopped, the rate of immunization will be reduced very quickly.

Classification of vaccines

Previously vaccines were divided into 3 types: detoxification vaccines, dead vaccines, live attenuated vaccines. Today with the advancement of biotechnology we have two more types: extraction vaccines and recombinant vaccines.

Vaccine detoxifies

Produced from foreign toxin of bacteria by losing toxicity but still retaining antigen. When the immune system receives the detoxification vaccine, they learn to fight the natural toxin. The immune system produces antibodies that neutralize toxins

For example: diphtheria vaccine, tetanus vaccine .

Inactivated vaccine (dead)

Produced from dead pathogenic microorganisms. These vaccines are safer and more stable than live vaccines, the dead pathogenic microorganisms cannot mutate again. The antigens primarily stimulate the immune response.

However, a dead vaccine with a weaker immune response than a live vaccine should be given in multiple doses or repeated injections to maintain immunity. This may limit people living in areas without regular medical care, unable to repeat the schedule.

For example: pertussis vaccine, typhoid vaccine, cholera vaccine, Salk vaccine (polio vaccine), Japanese encephalitis vaccine .

Live vaccine reduces virulence

Produced from pathogenic microorganisms or microorganisms identical to pathogenic microorganisms which have been reduced virulence no longer capable of causing disease. Because live, attenuated vaccines are almost the same as responses to natural infections, they produce a strong immune response and antibody production, often causing long-term immunity with just one or two doses.

For example: live BCG vaccine, typhoid vaccine, Sabin vaccine (polio vaccine), measles vaccine .

Special care must be taken to ensure the safety of a live vaccine, to ensure that it is no longer capable of causing disease or only cause a mild illness, and that the microorganism must have a stable genetic ability without returning virulence. original.

Extraction vaccine

Antigen is extracted from microorganisms.

For example: polysaccharide antigen of meningococcal bacteria, polysaccharide of pneumococcus .

Recombinant vaccine

Using state-of-the-art biotechnology, the gene coding for the microbial antigen required to make a vaccine is isolated and recombined into E. coli or an appropriate cell line.

For example: cholera vaccine, typhoid vaccine .

Scientists are studying recombinant vaccines on both bacteria and viruses for HIV, rabies and measles.

Issues to note

Subject was vaccinated

Children should be vaccinated extensively.

People at high risk for infection with pathogenic microorganisms without immunity. Children should be vaccinated widely, for adults who only vaccinate those at high risk.

Immunization must reach over 80% of people who are not immune to be capable of preventing outbreaks. Expanded immunization is the universal vaccination for most children, so its protection is very important, contributing significantly to the development of human resources of each country.

Subjects must never be vaccinated:

1. People who are suffering from high fever
2. There are signs of allergy
3. Live attenuated vaccines should not be administered to immunocompromised individuals or those currently taking immunosuppressant drugs, malignant patients, and pregnant women.

Vaccination time

Vaccinations before the epidemic season, enough to give the body time to form immunity

Basic immunity-producing vaccines must be vaccinated multiple times, with a reasonable distance between vaccinations suitable for each vaccine.

The duration of repeated vaccinations depends on how long the immune system is maintained and the protection of each vaccine remains effective.

Amount

Depending on the vaccine and the way it is administered. Too low doses will not afford to stimulate the immune response. Too large doses will lead to specific tolerances.

Injection

1. Strains: the classic street, now rarely used.
2. Injections: depending on the type of vaccine can be injected in the skin, under the skin, intramuscularly.
3. Oral administration: stimulates intestinal immunity rather than injections

Unwanted effects

1. Some vaccines can cause mild, temporary side effects such as fever, soreness, and swelling at the injection site. If vaccination is not guaranteed sterility can cause infection.
2. Convulsions, anaphylaxis have been encountered, but at a very low rate.

Standards of the vaccine

1. Safe: sterile, pure, non-toxic.
2. Effect: causing high immunity and long lasting.

Preserving the vaccine

The vaccine is well preserved from the time of manufacture until it is injected into the human body. The vaccines are usually not the same for storage, but they should be stored in dry, dark and cold conditions.

Heat and light destroy all vaccines, especially live, frozen vaccines that quickly destroy toxin vaccines.

Vaccinate to protect the health of yourself and those around you

The essence of vaccination is the use of a vaccine to stimulate the body to produce specific active immunity against a certain infectious disease. Up to now, there are about 30 infectious diseases with preventive vaccines and about 190 countries and territories have put vaccines into universal use for people and vaccination really plays a huge role for the whole society. .

Vaccines and vaccinations are the most effective preventive measures to reduce the morbidity and mortality rates of human infectious diseases. About 85% - 95% of vaccinated people will produce specific immunity to protect the body from disease and of course will not die or sequelae caused by the disease. Thanks to the worldwide annual vaccine, about 2.5 million children have been saved from death due to infectious diseases. Vaccines and immunizations play an important role in achieving the UN's millennium goal of reducing mortality for children under 5 years old worldwide.

Is the vaccine safe?

The vaccine is most safe. Any licensed vaccine is strictly tested through several stages of testing before it is approved for use and is regularly reassessed when it is available on the market.

Most vaccine reactions are usually minor and temporary, such as arm pain, mild fever or a injection site lump. The rate of severe reactions, which are life-threatening, requiring hospitalization is often very low, rarely occurring. The benefits of vaccination far outweigh the risks and many diseases, deaths, and deaths would occur without the vaccine.

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2. The only injection that integrates all types of baby vaccines