A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response. These molecules are called antigens, and they are present on all viruses and bacteria. By injecting these antigens into the body, the immune system can safely learn to recognize them as hostile invaders, produce antibodies, and remember them for the future. If the bacteria or virus reappears, the immune system will recognize the antigens immediately and attack aggressively well before the pathogen can spread and cause sickness. Vaccine Types Live-attenuated vaccines Live vaccines use a weakened (or attenuated) form of the germ that causes a disease. Because these vaccines are so similar to the natural infection that they help prevent, they create a strong and long-lasting immune response. Just 1 or 2 doses of most live vaccines can give you a lifetime of protection against a germ and the disease it causes. live vaccines are not suitable for people whose immune system does not work, either due to drug treatment or underlying illness. This is because the weakened viruses or bacteria can multiply too much and might cause disease in these people.
• Measles
• Mumps
• Rubella (MMR combined vaccine)
• OPV consists of a mixture of live attenuated poliovirus strains of each of the three serotypes, selected by their ability to mimic the immune response following infection with wild polioviruses, but with a significantly reduced incidence of spreading to the central nervous system. Inactivated vaccines Inactivated vaccines use the killed version of the germ that causes a disease. Because inactivated vaccines do not contain any live bacteria or viruses, they cannot cause the diseases against which they protect, even in people with severely weakened immune systems. However, inactivated vaccines do not always create such a strong or long-lasting immune response as live vaccines. So you may need several doses over time (booster shots) in order to get ongoing immunity against diseases.
• Polio (IPV)
• Hepatitis A
• Rabies Subunit, recombinant, polysaccharide, and conjugate vaccines Subunit, recombinant, polysaccharide, and conjugate vaccines use specific pieces of the germ — like its protein, sugar, or capsid (a casing around the germ). Because these vaccines use only specific pieces of the germ, they give a very strong immune response that’s targeted to key parts of the germ. They can also be used on almost everyone who needs them, including people with weakened immune systems and long-term health problems. Disadvantages: Identifying the best antigens in the pathogen for training the immune system and then separating them is not always possible. Only certain vaccines can be produced in this way.
• Hepatitis B
• Influenza
• Haemophilus Influenzae Type B (Hib) DNA vaccines are easy and inexpensive to make — and they produce strong, long-term immunity.
DNA Vaccines:
Still in experimental stages, DNA vaccines would dispense with all unnecessary parts of a bacterium or virus and instead contain just an injection of a few parts of the pathogen's DNA. These DNA strands would instruct the immune system to produce antigens for combating the pathogen all by itself. As a result, these vaccines would be very efficient immune system trainers. They are also cheap and easy to produce. #TypesOfVaccines #Vaccine

свернуть