Vaccines and Vaccination PDF

LEARNING OBJECTIVES Define passive and active immunization Recognize the different types of vaccines and understand their advantages and disadvantages Understand the concept of vaccine efficacy Understand the role of adjuvants Understand vaccine adverse events TYPES OF IMMUNIZATION Pas...

LEARNING OBJECTIVES Define passive and active immunization Recognize the different types of vaccines and understand their advantages and disadvantages Understand the concept of vaccine efficacy Understand the role of adjuvants Understand vaccine adverse events TYPES OF IMMUNIZATION Passive vs Active PASSIVE IMMUNIZATION ACTIVE IMMUNIZATION ADMINISTRATION OF ANTIBODIES ADMINISTRATION OF ANTIGENS Natural: Artificial: Natural: Artificial: e.g., Colostrum e.g., Antivenom Infection Vaccination TYPES OF IMMUNIZATION rememberyourimmunesystemisn't producingantibodies Passive Immunization Preformed antibodies specific to a particular antigen Immediate/short-lived protection No immunological memory Less used in veterinary medicine TYPES OF IMMUNIZATION Active Immunization Antigen is administered Induces an immune response and immunological memory Most common form of immunization Vaccines TYPES OF IMMUNIZATION Passive vs Active DO VACCINES REALLY WORK? Vaccination is the most efficient and effective method of controlling infectious diseases ever developed. Eradication of infectious diseases are great examples: Smallpox Rinderpest - “Cattle plague” VACCINE EFFICACY Vaccine Efficacy is generally expressed as a reduction in disease attack rate (AR) between the unvaccinated (ARU) and vaccinated (ARV) individuals: ARU − ARV VE = × 100 ARU Attack rate in this case may refer to different outcomes: Death; Severe Disease; Clinical Disease; Infection, and etc… The same vaccine may different efficacies for each outcome TYPES OF VACCINES HOW IT STARTED: HOW IT’S GOING: Live-attenuated Molecular based technologies Killed/inactivated vaccines Chimeric organisms Component vaccines Recombinant subunit Toxoid vaccines Recombinant-vector vaccines Nucleic acid vaccines Virus-like particles Reverse vaccinology TYPES OF VACCINES  Live attenuated vaccine Att. Dead Killed/Inactivated Pathogen Pathogen vaccine Attenuation Inactivation Pathogen Subunit Cloning Fractioning protein gene Nucleic acid Subcloning vaccine Expression Non Subunit vaccine pathogenic MO Live vector Recombinant vaccine subunit vaccine TYPES OF VACCINES DIVA vaccines Differentiate Infected from Vaccinated Animals NUCLEIC ACID VACCINES DNA vaccines Plasmid containing gene for the target antigen DNA in the cell generates mRNA from which the antigenic protein can be expressed Antigen presented by dendritic cells to lymphocytes NUCLEIC ACID VACCINES DNA vaccines NUCLEIC ACID VACCINES mRNA vaccines RECOMBINANT ORGANISM VACCINES Clone the gene that codes the immunogenic protein Insert it into a vector A virus incapable of causing disease in the host A vaccinated host will be infected with the vector Induces an immune response RECOMBINANT ORGANISM VACCINES Clone the gene that codes the immunogenic protein Insert it into a vector (virus incapable of causing disease in the host) A vaccinated host will be infected with the vector Induces an immune response ADJUVANTS Substances that facilitates or enhances immune response to an antigen with which it is combined ADJUVANTS ARE VACCINES DANGEROUS? VACCINE ADVERSE EVENTS As with any medication, the use of vaccines is not free of risks Adverse events should be recorded and reported Basic principles to identify a VAE 1. Consistency: repeatable in different groups receiving the vaccine 2. Specific: linked specifically to the vaccine concerned 3. Temporal relationship: vaccination should precede the event