Vaccination today is one of the methods of protection against infectious and viral diseases, including those that lead to serious complications. Thanks to vaccination, the human body learns to respond quickly if it encounters a pathology. A vaccine is an immunobiological preparation, the action of which is aimed at the formation of immunity to diseases. It is made from weakened or dead microbes, their metabolic products, or from their antigens. What is a live attenuated vaccine? It’s worth understanding this question.
Description of the problem
An attenuated vaccine is a live vaccine that is made on the basis of weakened microbes that have persistent harmlessness. Once in the human body, microbes begin to multiply, which leads to a vaccine infectious process. In many vaccinated people, the infection proceeds without symptoms and leads to the formation of persistent immunity. An example is the attenuated vaccine against rubella, tuberculosis, measles or polio.
Possible complications
An attenuated vaccine is one that is made from apatogenic pathogens that are weakened and have lost their pathogenic properties, as well as the ability to provoke the development of a disease in a person, but they can multiply in the body.
The infection that occurs after the introduction of such a vaccine develops a certain period of time, but does not show any symptoms, but it stimulates the formation of immunity to pathogenic microbes. Thus, the infection proceeds in a mild form, it activates the body's defenses.
But in some cases, a live attenuated vaccine provokes the development of pathology. This usually occurs with reduced immunity in humans or with residual virulence of the strain.
Today, five attenuated vaccines are used in medicine, these are:
- BCG - against tuberculosis.
- Oral polio - against poliomyelitis (OPV).
- Rotavirus vaccine.
- Against yellow fever (VL).
- Attenuated measles vaccine.
All of them rarely can cause the development of adverse reactions:
- BCG - a fatal infection (extremely rare) is found in people with immunodeficiency, as well as bone damage that caused certain batches of the vaccine.
- OPV - paralytic polio (extremely rare).
- Measles - febrile convulsions (convulsions) are extremely rare in children under five years of age, as well as purple thrombocytopenia, an allergic reaction to vaccine components, anaphylaxis, which requires emergency medical attention.
- Rotavirus - there are no data on the development of adverse reactions.
- JL - encephalitis, vaccine-associated viscerotropic pathology (extremely rare) usually occurs in people of advanced age.
Security
An attenuated vaccine is one that activates all components of the immune system, which provides long-term protection against infectious diseases. Since it contains live microbes, there is a certain risk of developing pathologies. Of course, the risk of the emergence of the ability of microbes to return to a pathogenic form and provoke the development of the disease is quite small, but in extremely rare cases, such side effects may appear:
- VAPP or vaccine-associated paralytic polio.
- Poliovirus.
- Local lymphadenitis, disseminated BCG infection.
- Retrovirus.
People with HIV cannot adequately respond to vaccination; the risk of developing adverse reactions is high enough. It is not recommended to vaccinate women during the period of bearing a child.
An attenuated vaccine is one that has a high risk of vaccination errors. Some vaccines, for example, are presented in the form of a dry powder. They must be diluted with a special solvent before administration. In this case, doctors can make a mistake using the wrong solvent or medication. Many vaccines require that doctors pay special attention to maintaining the cold chain in order to maintain their activity.
Thus, the risk of developing pathologies is as follows:
- The ability of microbes to return to a pathogenic form.
- The possibility of applying time to people with HIV.
- The risk of developing infections.
- Procedural errors.
- The introduction of a vaccine during pregnancy.
Vaccine Use Restrictions
An attenuated vaccine is one that is contraindicated in such cases:
- The period of bearing a child.
- Acute diseases of an infectious and non-infectious nature.
- Exacerbation of chronic pathologies.
- Immunodeficiency conditions.
- Blood cancer, the appearance of malignant neoplasms.
- The passage of radiation therapy.
- Reception of immunosuppressants.
- Tendency to severe allergic reactions.
- The development of complications on the previous vaccination.
Conclusion
The fight against infectious diseases through vaccination is currently one of the greatest achievements of man in the field of medicine. Today, the prevention of infectious diseases is a powerful, safe and quite effective way to fight infections of different origins. In medicine, many vaccines are used, including live ones, which form a defense against many diseases, for example, measles, polio, rubella, etc.
Today, in medical practice, WHO recommended the use of five attenuated vaccines. These are BCG (tuberculosis), OPV (polio), VL (yellow fever), rotavirus and against measles. With proper conduct and compliance with all the recommendations of doctors, the risk of developing adverse reactions is minimized.