Control of viral diseases by immunization/vaccine Flashcards
What is a veccine ?
a preparation of suspensions of killed or attenuated microorganisms, or products or derivatives of microorganisms, that can be used safely to induce an immune response and confers prevention of infection, a reduction in disease severity or a decreased rate of hospitalization on subsequent exposure to a pathogen.
what is an antigenic ?
substances that cause the body’s immune system to react, especially causing it to produce antibodies
what are vaccines made of that make them procure immunity ?
they contain virus proteins with antigenic areas called epitopes
(viral epitopes induce both B-cell and T-cell immunity)
adjuvant:
substance that enhances the body’s immune system to an antigen
Immunoprophylaxis against viral illnesses
vaccines or antibodies-containing preparatons
Active Prophylaxis (Vaccines)
the normal vaccines to immunise people
Passive Prophylaxis (immunity)
antibodies from another host (majorly made of blood and contain antibodies), used when the person is diseased and cannot be protected by vaccination)
what generates the memory of antibodies ?
it’s the memory B cells
what happens if the incubation period is too short (of the pathogen)
the memory response may not be enough because memory cell B doesn’t have the time to make the antibodies reach the protection treshold and the pathogen has a rapid onset of symptoms (that means cell B don’t have time to re-produce antibodies after the 1st time)
but in some cases after the primary vaccination the antibodies remain above the protection treshold and provide lifelong immunity
Passive immunisation:
(immunoglobulin), it only stays for 4 months and then the antibodies decay), it’s just a partial protection
in some cases, it has an outward reaction and instead the antibodies help the virus spread (dengue)
prophylactic immunisation VS passive:
the prophylactic one is fully effective prior to exposure and can still be effective postexposure (at early point); on the other hand, the passive one when administered postexposure decreases its effectiveness once the disease progresses
viral vaccines function:
prevent infection by antigenic stimulation of the host and induction of memory T cells, resulting in the generation of neutralizing antibody and cytotoxic T cells.
Inactivated (killed) vaccines
consist of chemically inactivated whole virions (e.g. rabies, formalin-killed polio vaccine).
Non-living vaccines
prepared from fractionated virus containing immunogenic proteins, (e.g. ‘split’ influenza vaccine), or by recombinant DNA techniques (e.g. hepatitis B vaccine) or nucleic acid (SARS-CoV-2).
Live vaccines
prepared from viruses,which,by manipulation in the laboratory are no longer pathogenic but retain their immunogenicity (e.g. YF, oral polio, mumps, measles, rubella).
