Vaccination PDF

Vaccination From a textbook-based study of immunology Saif A. Mohammed, MSc Middle Technical University November, 2021  Adaptive immunity Adaptive immunity can be further classified into two subgroups: active immunity and passive imm...

Vaccination From a textbook-based study of immunology Saif A. Mohammed, MSc Middle Technical University November, 2021  Adaptive immunity Adaptive immunity can be further classified into two subgroups: active immunity and passive immunity. A. Active immunity : - in which the host develops an adaptive immunological response and produces the cells and factors responsible for the immunity. Active immunity can persist for a long time in the host.. Active immunity can be acquired through natural immunity or vaccine-induced immunity.  Classification of Active immunity Active immunity can be acquired through natural immunity or vaccine- induced immunity. 1. Natural immunity is acquired from exposure to the disease organism through infection with the actual disease. 2. Vaccine-induced immunity is acquired through the introduction of a killed or weakened form of the disease organism through vaccination.  Passive Immunity Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system. For example, passive immunity occurs when a baby receives a mother's antibodies through the placenta or breast milk. It can also occur when a person receives an injection of antibodies to protect against the effects of a toxin such as snake venom. Vaccination: The act of introducing a vaccine into the body to produce protection from a specific disease. Immunization: A process by which a person becomes protected against a disease through vaccination. This term is often used interchangeably with vaccination or inoculation. Vaccine : - A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.  Classification of Vaccines The main types of vaccines that act in different ways are:  Live-attenuated vaccines  Inactivated vaccines  Subunit, recombinant, conjugate, and polysaccharide vaccines  Toxoid vaccines  mRNA vaccines  Viral vector vaccines  Live-attenuated vaccines Live-attenuated vaccines inject a live version of the germ or virus that causes a disease into the body. Although the germ is a live specimen, it is a weakened version that does not cause any symptoms of infection as it is unable to reproduce once it is in the body.  Live-attenuated vaccines can be made to create immunity against viruses or bacteria, but they are more commonly used for viruses. The types of live-attenuated vaccines The types of diseases that live-attenuated vaccines are used for include:  Measles, mumps, and rubella (MMR combined vaccine)  Rotavirus  Smallpox  Chickenpox  Yellow fever  Inactivated vaccines An inactivated vaccine uses a strain of a bacteria or virus that has been killed with heat or chemicals. This dead version of the virus or bacteria is then injected into the body. The types of diseases that inactivated vaccines are used for include:  Hepatitis A  Flu  Polio  Rabies  Subunit, recombinant, conjugate, and polysaccharide vaccines Subunit, recombinant, conjugate, and polysaccharide vaccines use particular parts of the germ or virus. They can trigger very strong immune responses in the body because they use a specific part of the germ These types of vaccines are used to create immunity against the following diseases:  Hib (Hemophilus influenza type b)  Hepatitis B  Human papillomavirus (HPV)  Pneumococcal disease  Meningococcal disease  Shingles  Toxoid vaccines Toxoid vaccines use toxins created by the bacteria or virus to create immunity to the specific parts of the bacteria or virus that cause disease, and not the entire bacteria or virus. The immune response is focused on this specific toxin.  Toxoid vaccines do not offer lifelong immunity and need to be topped up over time.  Toxoid vaccines are used to create immunity against diphtheria and tetanus.  mRNA vaccines This technology has been in development for decades. mRNA vaccines have benefits such as short manufacturing times and low manufacturing costs. However, they have to be kept at low temperatures due to the fragility of the mRNA.  mRNA vaccines work by triggering an immune response from proteins they synthesize. They induce both cellular and humoral immunity.  The first mRNA vaccine was approved this year for COVID-19. There is some misinformation that mRNA vaccines can alter a person’s DNA. However, they are not able to do this.  Bibliography  U.S. government Vaccine Research Center: Information regarding preventive vaccine research studies  CDC.gov – 'Mercury and Vaccines (Thimerosal)', US Centers for Disease Control  Immunizations, vaccines and biologicals: World Health Organization (WHO's global vaccination campaign website)  U.S. Department of Health and Human Services (HHS)