Vaccination helps to create active immunity against some serious diseases. Currently, this method is recognized as the most effective, allowing to prevent the development of various serious pathologies of an infectious, bacterial and viral nature. Live vaccine helps to create lasting immunity. This particular form of immunization medication has several advantages and disadvantages that everyone should be familiar with.
What are live vaccines?
To create live vaccines, weakened strains of pathogens are used, which begin to multiply at the injection site. Such agents fully retain their immunogenic properties. Immunization with live vaccines does not cause a clinical picture of the manifestation of the disease (in most cases). A vaccine infection leads to the formation of a fairly stable immunity: humoral, cellular and secretory.
Weakened (attenuated) strains can be obtained due to inactivation of the gene, which is responsible for the virulence of the microorganism. For inactivation, chemical and physical effects are used. Many live vaccines are dry. This allows you to extend their shelf life. Dry live vaccines can be stored for more than 12 months at a certain temperature (2-8 ° C). To create a stable immunity, it is sometimes enough to enter the drug once.
A variety of live vaccines are divergent vaccines. In their manufacture, microorganisms are used that are closely related to infectious agents, but are not able to cause disease. An example of such a vaccine is BCG, it is obtained from bovine tuberculosis mycobacteria.
Benefits
Compared with non-living vaccines, drugs with weakened strains of pathogenic bacteria have several advantages:
- The minimum dose of the drug.
- The rapid development of immunity.
- The presence of various methods of introduction into the body.
- The most natural immunogenicity.
- High efficiency (if used correctly).
- Low cost.
- Lack of preservatives.
- Activation of all types of immunity.
Disadvantages of Live Vaccines
According to experts, attenuated strains of pathogenic microorganisms used to create vaccines can cause the development of this disease (it happens extremely rarely). This is associated with the presence of a weakened immunity in the patient.
Live vaccine is very sensitive to temperature extremes. Therefore, a negative reaction of the body is almost inevitable if negligence was allowed regarding the proper storage or transportation of the drug. Also, a vaccine spoiled in this way can completely lose its ability and cause absolutely no reaction of the body.
Doctors recommend avoiding combining a live vaccine with other vaccination medications. Otherwise, negative reactions of the body may develop or the funds will lose their effectiveness.
Live polio vaccine
A serious infectious disease is polio, in which the brain and spinal cord are affected. Pathology leads to damage to the nervous system and paralysis. In the middle of the last century, scientists developed a live vaccine (OPV) that can protect humanity from this terrible disease.
The product is available in liquid form and is intended for oral use. It has a bitter-salty taste, and therefore, when instilling, it is recommended to avoid getting the drug on the tongue. The drug should fall on the tonsils (there are no taste buds), where the formation of stable immunity begins. Grafting a live vaccine is recommended after inactivated use.
According to immunologists, the vaccine contains all three types of polio, which helps protect the body from all known variations of this ailment. Complications of the drug are extremely rare. However, many parents try to avoid vaccinating their children with this vaccine.
How does it work?
Sabin vaccine (OPV) after ingestion is stored for a long time in the intestine and causes the formation of immunity, similar to that which would develop after a disease. The first vaccination is carried out at the age of 6 months. Pre-infants are vaccinated with an inactivated vaccine twice - at 3 and 4.5 months. As a result, antibodies should begin to be produced that can recognize and protect the body from the pathogenic pathogen. Live polio vaccine also stimulates the production of interferon, which also positively affects the state of the immune system.
Reviews
In the process of research, it was found that OPV is much more effective than inactivated vaccines. Doctors recommend that you go through the full polio vaccination schedule and be sure to use a live attenuated vaccine. At the same time, parents are in no hurry to agree to the use of such a drug. This is associated with a risk of side effects: vaccine-associated poliomyelitis, fever, stool disorder, loss of sensation in the extremities, impaired gait.
Of course, the use of live vaccines can provoke the appearance of a negative reaction of the body. However, such cases are recorded extremely rarely. Children born with immunodeficiency, congenital pathologies of the gastrointestinal tract or having a weakened protective system, for example, after suffering a serious illness, can suffer. In these cases, only an inactivated vaccine is allowed.
How to protect against measles?
Measles is a highly contagious infectious disease that can be infected by anyone, regardless of gender or age. In childhood, pathology is much easier to tolerate. A live measles vaccine will help build immunity . One-component vaccine is produced by a domestic manufacturer. An Indian-made vaccine is also considered effective.
The product is released in the form of a dry powder, which is diluted with a special solvent. The finished vaccination can be stored for no more than an hour. Immunization with a monovalent vaccine avoids infection with an illness or transfer it in a mild form.
Scheduled primary vaccination is indicated at the age of 12-14 months. Re-enter the vaccine is necessary at 6 years. There is the possibility of an individual schedule of vaccination, which should be drawn up by an immunologist.
Contraindications and complications
Frequent negative reactions of the body to the administration of a live measles vaccine are symptoms such as fever, skin rashes, inflammation of the lymph nodes, and coughing. Experts say that this is a completely normal reaction of the body.
In children, such symptoms rarely develop. Basically, the introduction of a live measles vaccine is well tolerated. Before vaccination, it is necessary that the doctor examined the child (adult patient) and exclude the presence of contraindications (permanent and temporary). It is important that the person is completely healthy. The vaccine is forbidden to be administered to women in a position, to people who have a history of tuberculosis and complications caused by previous vaccination.
Rubella vaccination
Rubella is another childhood ailment that adults can take quite hard. The vaccine (live) is considered the most effective means of preventing infection. Pathology is especially dangerous for pregnant women.
Live vaccine (single-component) is produced by Croatian, French and Indian specialists. According to reviews, side effects often develop in adults who have been vaccinated with a weakened vaccine. A slight increase in lymph nodes, general weakness, fever, skin rashes disappear on the second day.
Persons prone to severe allergic reactions, it is recommended to be under the supervision of specialists after administration of the drug.