Live vaccines are grown in a pharmacology laboratory to produce attenuated pathogens of a disease. These attenuated pathogens are injected into the human body, activating the immune system to respond.
What are live vaccines?
Live vaccines are grown in a pharmacology laboratory to produce attenuated pathogens of a disease. Live vaccines involve immunization by functional germs that are delivered to the organism. The germs are supplied in an attenuated form, but are able to multiply and thus prevent the outbreak of a disease. The attenuated form is also called attenuated. Live vaccines are administered as an injection (spray vaccination) or orally (oral vaccination). If the vaccine is used for a viral disease, for example, it is referred to as a live attenuated influenza virus vaccine (LAIV). The reason for this is that, by definition, viruses are not living organisms and cannot reproduce. Therefore, the term live vaccination is not correct with regard to viruses, but is nevertheless classified under it. A major advantage of live vaccination is that once immunized, the protection lasts for life and does not need to be refreshed regularly. However, vaccination with live vaccines is not suitable for people who have a weakened immune system. In principle, this form of vaccination can cause side effects similar to the actual clinical picture. As a rule, however, these subside after 3-4 days. The first pharmacologically developed vaccines often caused disease, but today these offer a high level of protection and significantly reduce the risk of falling ill.
Pharmacological action
The most important component of the immune system is antibodies. The main ones responsible are the so-called T lymphocytes and the B lymphocytes. These are components of leukocytes, the white blood cells. They attach to the pathogens and activate mechanisms to destroy the pathological agents. The pathogens of the live vaccines are grown under special pharmacological conditions so that they are so weakened that they cannot cause actual disease. When the live vaccine is injected into the body, the body is deliberately “infected.” Vaccines that have only individual characteristics of a pathogen are particularly suitable for this purpose. Often, these are genetically produced and the pathogen is thereby attenuated to a minimum. Despite the attenuated form, the pathogens are able to multiply in the organism. The multiplication prompts the immune system to become active. The immune system starts to fight the pathogens, although they are not harmful to the body due to their special cultivation. Thus, the immune system is in a training phase and picks up the characteristics of the pathogen to form suitable antibodies.
Medical application and use
Vaccination with a live vaccine is also known in medicine as active immunization. The body is stimulated to produce antibodies after the injection. The goal of such a vaccination is therefore not to support the immune system, but to strengthen the body’s own defense functions by suggesting pathogens. Typical examples of such vaccination are diseases such as:
- Rubella – an infectious disease caused by the rubella virus.
- Mumps – a viral disease caused by the mumps virus (paramyxovirus parotitidis).
- Smallpox – a viral disease caused by the pathogen orthopoxvirus variola.
- Chickenpox – an infectious disease caused by the varicella zoster virus.
- Yellow fever (Siamese disease) – an infectious disease caused by the yellow fever virus.
- Tuberculosis (TBC) – a bacterial infectious disease caused by Mycobacterium tuberculosis.
- Typhoid fever (typhoid fever) – an infectious disease caused by the bacterium Salmonella Typhi.
- Rotavirus infection – an infectious disease caused by the rotavirus.
- Flu (influenza) – a group of viral diseases caused by the influenza virus.
Live vaccines for different diseases can be injected simultaneously. If not injected simultaneously, there should be about 14 days between vaccinations. However, this applies only to live vaccines, not for dead vaccines.However, one disadvantage of vaccination with live vaccines is that it initially only stimulates the activity of the immune system and does not provide immediate protection. This occurs only after some time, when the body has successfully fought the injected disease. Immunization by death vaccines, in comparison, has an immediate effect (eg, rabies, tetanus).
Risks and side effects
Even today, many parents think that there is an increased risk of allergies, asthma or sudden infant death syndrome in a “fully vaccinated” infant. Through numerous studies over many years and also the further development of vaccines, however, it has been proven that this is not the case. However, acute skin irritation at the injection site, a general feeling of weakness, and headaches and pain in the limbs may occur. In this context, patients often report flu-like symptoms, which, however, quickly subside. In rare cases, a severe allergic reaction may occur. In individual cases, an outbreak of the disease may also occur due to the injection of the pathogens. In this case, however, the disease and its symptoms are significantly weakened. If the patient suffers from a functional disorder of the immune system, live vaccinations should generally be avoided. In general, it is important to take it easy after a vaccination and to support the body in fighting the injected pathogens.
