immunity and vaccinations 3.1.7

• antibodies recognise specific antigens and are made by lymphocytes
• lymphocytes are found as B cells for antibodies and T cells for antitoxins
• phagocytes engulf pathogens and are non specific so they engulf any pathogen they come across
• memory cells are specific to a particular pathogen and 'remember' the pathogen should you be infected again and this means you have a much quicker and greater immune response
• 1. every bacteria and virus has different antigens on its surface. these are recognised by antibodies, which are made by B lymphocytes
• 2) the antibodies bind to the antigens
• 3) bacteria are clumped together by antibodies to stop the bacteria causing as much damage and makes them easier to destroy
• 4) the antibody-coated bacteria are engulfed by phagocytes by phagocytosis
• the primary immune response is short lived lymphocytes and antibodies
• the secondary immune response is memory cells and long lived lymphocytes
• when bacteria release toxins in the body, instead of using an antibody from a B cell lymphocyte, the body uses an antitoxin from a T cell lymphocyte
• vaccinations consist of an injection of a weakened or dead pathogen - sometimes just antigens. they provide immunity against a specific disease for different periods of time, depending on the vaccination
• 1. a person is injected with a specific pathogen for weakened measle virus
• 2) the measles antibodies bind with the weakened measle pathogens
• 3) the measles virus begins spreading through the population and both vaccinated and unvaccinated people are exposed
• 4) the person who was not immune to measles catches measles and becomes ill, whereas the vaccinated person was fine
• herd immunity is when enough people have had the vaccine so the vaccinated people reduce the spread of the virus and can protect the unvaccinated
• the method of prevention of dead pathogens involves dead pathogens that still have the antigens
• for dead pathogens, your immune system makes antibodies against a specific antigen
• the advantages of dead pathogens are that memory cells are created so there is long term immunity
• the disadvantages of dead pathogens is that people may suffer some mild symptoms of the disease or side effects
• the method of immunity of weakened pathogens involves live pathogens with antigens that cannot cause any disease
• for weakened pathogens, your immune system makes antibodies against a specific antigen
• the advantages of weakened pathogens are that memory cells are created so there is long term immunity
• the disadvantages of weakened pathogens is that people may suffer some mild symptoms of the disease or side effects
• the method of prevention of using similar but less harmful pathogens involves using a pathogen with similar shaped antigens that wont cause a serious illness
• for similar pathogens, your immune system makes antibodies against a specific antigen
• the advantages of similar pathogens are that memory cells are created so there is long term immunity
• the disadvantages of similar pathogens is that people may suffer some mild symptoms of the disease or side effects
• the method of prevention of using mono-colonial antibodies involves injecting a rodent with the pathogen or toxin and then removing the immune cells from the animal which are used to produce antibodies, which are injected into the person
• for mono-clonal antibodies your body doesnt make the antibodies itself
• the advantages of mono-colonial antibodies is that there is immediate protection against a disease that may kill you before your immune system has a chance to make antibodies
• the disadvantages of mono-clonal antibodies is that there is no long term immunity
• the MMR vaccine is a vaccine against measles, mumps and rubella that is usually given at 12 months
• andrew wakefield published a paper, creating a link between MMR vaccine and autism in children and people believed it and stopped vaccinating their children
• however epidemiological studies were conducted and refuted the concerns of the link and Andrews medical title was removed
• Andrew was paid money if he found a link between MMR and autism