Vaccines and Vaccination PDF

PID: VACCINES & VACCINATION PEDRO BITTENCOURT, DVM, MSC, PHD 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...

PID: VACCINES & VACCINATION PEDRO BITTENCOURT, DVM, MSC, PHD 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 HISTORY OF IMMUNIZATION 15th century China - Variolation Observed that individuals who recovered from smallpox never suffered from it a second time Deliberately infecting children by placing the dried scabs in a small incision in the arm, resulting in local disease (less severe and lower mortality) A The technique spread westward along the Silk Road until it eventually reached the Ottoman Empire—modern Turkey It was widely employed across the Middle East Reached England in the 1700’s EiEE HISTORY OF IMMUNIZATION set 1796 - Edward Jenner Milkmaids seemed to not fall ill from smallpox Infection with cowpox protected then against smallpox Pus from a lesion of cowpox injected into a boy named James Phipps Later, he infected James Phipps with smallpox The boy survived Vaccination ➡ Vacca means cow in Latin HISTORY OF IMMUNIZATION Louis Pasteur 1879 - Pasteurella multocida vaccine in chickens (attenuated bacteria) For many, the birth of Immunology 1881 - Anthrax vaccine in ruminants 1885 - Rabies vaccine 9y boy bitten by a rabid dog 12 consecutive injections The boy survived 1886 - Mortality dropped to 0.5% after vaccination TYPES OF IMMUNIZATION Passive vs Active PASSIVE IMMUNIZATION ACTIVE IMMUNIZATION ADMINISTRATION OF ANTIBODIES ADMINISTRATION OF ANTIGENS AQrreesffa.fi Natural: Artificial: Natural: Artificial: e.g., Colostrum e.g., Antivenom Infection Vaccination is at producingth respond body bodyis an toUspd bit producing your your showyou to thing imoneus pence  n TYPES OF IMMUNIZATION 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 adf.EE Induces an immune response and immunological memory Most common form of immunization Vaccines TYPES OF IMMUNIZATION Passive vs Active Booster actinteproduction to ofantibiotic Letmemyalls 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” SMALLPOX VACCINE IMPACT SMALLPOX ERADICATION 1.1959: WHO resolution on smallpox eradication 1 2 3 2.1967: start of intensified eradication program 3.1977: Last case of smallpox 1980: WHO officially declares smallpox eradicated RINDERPEST ERADICATION Middle East Africa Asia Europe VACCINE EFFICACY Vaccine Efficacy is generally expressed as a reduction in disease attack rate (AR) between the unvaccinated (ARU) and vaccinated (ARV) individuals: vaccintal ARU − ARV VE = × 100 ARU chucuttal 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 virus Component vaccines Recombinant subunit Toxoid vaccines Recombinant-vector EL vaccines Etaples Nucleic acid vaccines Virus-like particles Reverse vaccinology andunderstand tegenuPWA hook TYPES OF VACCINES  Live attenuated vaccine Att. Dead Killed/Inactivated Pathogen Pathogen vaccine Attenuation Inactivation Pathogen Subunit thevirus of Cloning Fractioning protein Proteon gene Subunit 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 Vacanti save thegreenone test The are attracan Dunt true in green 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? VACCINES & AUTISM Andrew Wakefield - Lancet, 1998 “Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children” Relation between the MMR (Measles, Mumps, Rubella) vaccine with autism and IBD Issues: No control group No statistical analysis Vague conclusions Misrepresentation of study subjects medical records VACCINES & AUTISM Failed to disclose financial interests Funded by lawyers who had been engaged by parents in lawsuits against vaccine manufacturers Had applied for a patent on a new vaccine against measles 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  Results: 1,258,712 vaccine doses 496,189 cats 2,560 VAAEs 92% in 0-3 days 51.6 VAAEs/10,000 cats 4 cats died within 48h 0.081 deaths/10,000 cats  Results: 1,226,159 dogs 496,189 cats 4,678 VAAEs 38.2 VAAEs/10,000 dogs 3 dogs died 0.024 deaths/10,000 dogs QUESTIONS? THANK YOU FOR ATTENDING! ©2021 Ross University School of Veterinary Medicine. All rights reserved.