Although the term vaccine (vaccine) is widely used, everyone has been vaccinated, but there are still quite a lot of people who misunderstand about vaccines, thinking that vaccines are used to treat diseases, when in fact this is a preparation. used to prevent disease in healthy people.
Vaccine (also known as vaccine) is an antigenic preparation derived from pathogenic microorganisms or microorganisms with antigenic structure similar to pathogenic microorganisms, which have been prepared to ensure safety. absolutely necessary, used to enter the body of a healthy person and cause the body to create a specific and active immune state against pathogens.
Vaccines contain weakened versions of the virus or a close virus-like version, usually live attenuated, or killed, viruses or bacteria, called antigens . Antigens cannot cause signs or symptoms of disease, and when introduced into the body, the body will recognize it as a “foreign object”, stimulating the immune system to produce antibodies that neutralize the effect. pathogens, just like natural infections. The process of making antibodies usually takes a few weeks, can cause some mild symptoms such as fever. But this is a normal expression and is considered a sign of the body’s immune response. After this “mimicking” infection process ends, the body will produce lymphocytes with immune memory, ready to respond quickly when encountering pathogens again in the future, helping the body may actively prepare against the pathogen upon exposure to future viruses.
To make a vaccine, it usually takes a lot of research and testing time.
It can be said that the invention of the vaccine by scientist Enner in 1796 is a great medical achievement of mankind. Since the birth of the vaccine, mankind has really acquired a super weapon, the sharpest and most effective to actively prevent dangerous infectious diseases.
To make a vaccine, it usually takes a lot of research and testing time. When a new vaccine is developed, it needs to go through animal trials, then to a small group of people, and then it can be used in the public. These testing steps help to ensure the safety of the vaccine as well as make sure it works. Human trials of vaccines are often expensive, and research institutions will need to recruit volunteers to participate in the trials.
Vaccines help improve the body’s resistance to disease. When immunizing, the body’s immune system recognizes the vaccine as a foreign object and destroys and remembers them, thereby creating an immune memory. Later, after the real pathogen enters the body, the immune system will attack the pathogen quickly and effectively to protect the body against that disease.
Thanks to vaccines, millions of children do not die from infectious diseases. Vaccinated people will not get disease or sequelae caused by the disease.
When vaccination programs work well, most people get vaccinated against a disease, sometimes that disease disappears completely from the community and the vaccination program can stop. For example smallpox. However, some diseases such as measles, if the vaccination program is stopped, the vaccination rate will decrease very quickly.
Vaccines include many components, but in general, the main components are antigens, excipients and preservatives.
Some vaccines come in reusable tubes.
Antigen is the most important component, helping the body recognize this as an invader. Depending on the vaccine, the antigen can be a molecule from the virus such as a DNA sequence or a protein, or it can be a live weakened virus. For example, the measles vaccine contains the measles virus that has been manipulated to reduce virulence.
When the body is vaccinated with measles vaccine, the immune system recognizes the protein sequence of the measles virus and tries to create antibodies to eliminate it.
Excipients are substances that amplify the immune response to antigens. Vaccines may or may not have adjuvants, depending on the type of vaccine.
Some vaccines are contained in tubes that can be used many times, so a preservative must be included to ensure that they can be kept for a long time without fear of bacteria entering. One of the most popular preservatives is thimerosal, because it contains the mercury compound ethylmercury. According to the CDC website, the mercury compounds in thimerosal are not harmful to the body.
However, the use of disposable vaccine tubes is increasingly common. These tubes will not need preservatives like thimerosal.
The vaccine development process can be divided into six phases:
Normally, it can take more than 10 years to create a vaccine. Once the licensing process is complete, the pharmaceutical company can mass produce the vaccine.
Previously, vaccines were divided into three types: antitoxin vaccines, dead vaccines, and live attenuated vaccines. Today, with the advancement of biotechnology, we have two more types: isolated vaccines and recombinant vaccines.
Produced from bacterial exotoxins by losing virulence but retaining antigenic properties. When the immune system receives the antitoxin vaccine, it learns to fight the toxin naturally. The immune system produces antibodies that neutralize the toxin
For example: diphtheria vaccine, tetanus vaccine…
Produced from dead pathogenic microorganisms. These vaccines are safer and more stable than live vaccines, dead pathogenic microorganisms cannot mutate again. Antigens primarily stimulate the immune response.
However, a dead vaccine has a weaker immune response than a live vaccine, so it should be given in multiple doses or as a booster to maintain immunity. This can be limited for people living in areas where regular medical care is not available and cannot be re-vaccinated on time.
For example: pertussis vaccine, typhoid vaccine, cholera vaccine, Salk vaccine (prevents polio), Japanese encephalitis vaccine…
Produced from pathogenic microorganisms or microorganisms similar to pathogenic microorganisms have been reduced virulence no longer capable of causing disease. Because live, attenuated vaccines closely mimic the response to natural infection, they induce a strong immune response and antibody production, often conferring lasting immunity with only 1 or 2 doses.
For example: live BCG vaccine, typhoid vaccine, Sabin vaccine (polio prevention), measles vaccine…
When using, it is necessary to pay special attention to the safety of live vaccines, to ensure that they are no longer capable of causing disease or only cause mild disease, and the microorganism must have stable genetics and do not return to virulence. initial.
Antigens are isolated from microorganisms.
For example: polysaccharide antigen of meningococcus, polysaccharide of pneumococcus…
By modern biotechnology, genes coding for microbial antigens required to make vaccines are isolated and recombined into E. coli or a suitable cell line.
For example: cholera vaccine, typhoid vaccine…
Scientists are working on recombinant vaccines both on bacteria and viruses for HIV, rabies and measles.
Children should be widely vaccinated.
People who are at high risk of infection with pathogenic microorganisms do not have immunity. Children should be vaccinated widely, and adults should only vaccinate high-risk groups.
Immunization must reach more than 80% of the subjects without immunity to be able to prevent epidemics. Expanded immunization is universal vaccination for most children, so its protection area is very large, making an important contribution to the development of human resources of each country.
Immunization before the epidemic season is enough for the body to have time to form immunity
The vaccines that create basic immunity must be vaccinated many times, there should be a reasonable interval between vaccinations suitable for each type of vaccine.
The duration of booster vaccination depends on how long the protective immunity of each vaccine is maintained.
Depends on the type of vaccine and the way it is introduced into the body. Doses that are too low will not be able to stimulate an immune response. Excessively large doses lead to specific tolerability.
The vaccine is well preserved from the time it is manufactured until it is injected into the human body. Routine storage of vaccines is not the same, but all need to be stored in dry, dark and cold conditions.
Heat and light destroy all vaccines, especially live vaccines, freezing rapidly destroys antitoxin vaccines.
The essence of vaccination is to use a vaccine to stimulate the body to produce specific active immunity against an infectious disease. Up to now, there have been about 30 infectious diseases with vaccines to prevent diseases and about 190 countries and territories have put vaccines into universal use for people, and vaccination really plays a huge role in the whole society. .
Vaccines and vaccinations are the most effective preventive measures to reduce the morbidity and mortality from infectious diseases of mankind. About 85% – 95% of people who are vaccinated will generate specific immunity to protect the body from disease and of course will not die or have sequelae caused by the disease. Thanks to vaccines every year around the world, about 2.5 million children are saved from dying from infectious diseases. Vaccines and immunizations play an important role in achieving the United Nations Millennium Development Goal of reducing under-five mortality worldwide.
Vaccines are mostly safe. Any licensed vaccine is rigorously tested through several stages of testing before it is approved for use and is regularly re-evaluated as it becomes available on the market.
Most vaccine reactions are usually minor and temporary, such as arm pain, low-grade fever, or a lump at the injection site. The rate of severe, life-threatening reactions requiring hospitalization is usually very low, rarely occurring. The benefits of vaccination far outweigh the risks and many illnesses and deaths would occur without a vaccine.