WEEK 5: VACCINATION AND PUBLIC HEALTH Flashcards
What are vaccines?
Substances that resemble disease causing agents that triggers the immunity system to form antibodies against the disease, storing the response in memory cells and if infected in the future the immune system immediately mounts a response.
“Vaccines work by training and preparing the body’s natural defences – the immune system – to recognize and fight off viruses and bacteria. If the body is exposed to those disease-causing pathogens later, it will be ready to destroy them quickly – which prevents illness ‘’ — WHO
1st vaccine was discovered in the 18th century.
1796 –Who developed and documented the firstvaccineforsmallpox, “Father of Immunology’’?
What was his observation?
What did he name the procedure?
1st vaccine was discovered in the 18th century
1796 –Edward Jennerdevelops and documents firstvaccineforsmallpox
“Father of Immunology’’
Jenner made an observation that milkmaids were immune to smallpox after infection with cowpox.
He inoculated an 8-year-old boy James Phipps with cow pox pus then later with smallpox material and there was no infection.
He named the procedure Variolae vaccinae (“smallpox of the cow”) “vaccination.”
Live attenuated vaccine
Describe the 4 main types of vaccines.
- Live Attenuated vaccines- use a weakened (or attenuated) form of the germ that causes a disease.
- MMR, smallpox, yellow fever, rotavirus, chicken pox - Inactivated vaccines- use the killed version of the germ that causes a disease.
- hepatitis A, Flu Shot, Polio Shot, rabies, SINOVAC - Subunit, recombinant, polysaccharide, and conjugate vaccines use specific pieces of the germ—like its protein, sugar, or capsid.
- Hib, HepB, whooping cough, pneumo/meningo-mococcal, shingles, HPV - Toxoids use a toxin (harmful product) made by the germ that causes a disease.
- Diphtheria, Tetanus
Describe the MOA of DNA/ RNA vaccines.
DNA/RNA vaccines – contains DNA/RNA material that codes for the pathogen proteins (Antigens) that gives body cells instruction to produce the protein found in the pathogen triggering an immune response against the protein.
Clinical trials Influenza, Zika, CMV, PFIZER, MODERNA
Describe the MOA of Recombinant vector vaccines (platform-based virus).
Recombinant vector vaccines (platform-based virus)- another weak pathogen carries the genetic material of the target pathogen and gives the body cells instruction to make pathogen proteins that triggers the immune response against the protein. Clinical trials: Ebola, malaria, Zika, Influenza, JnJ, ASTRAZANECA, SPUTNIK
When did WHO initiative, the Expanded Program on Immunization (EPI) to ensure that infants/children and mothers have access to routinely recommended infant/childhood vaccines?
State the 6 vaccine-preventable diseases which were initially included in the EPI.
Outline the 3 components of EPI include:
A WHO initiative, the Expanded Program on Immunization (EPI) was established in 1976 to ensure that infants/children and mothers have access to routinely recommended infant/childhood vaccines.
Six vaccine-preventable diseases were initially included in the EPI: tuberculosis, poliomyelitis, diphtheria, tetanus, pertussis and measle.
More vaccines added as knowledge of vaccine preventable diseases increases and development of new vaccines.
Components of EPI include:
- routine immunization of children and other vulnerable groups
- Supplementary immunizations activities
- vaccine preventable disease surveillance
Nations adopt from EPI and create their own national immunizations policies and programs
Outline key issues to be considered when deciding on the introduction of a vaccine.
THE VACCINES
*Performance of the already available vaccine
*Economic and financial issues
*Availability of vaccine supply.
THE DISEASE
*Public health and political authorities’ alignment with the global and regional recommendations.
*Disease burden
*Status of other disease prevention measures.
STRENGTH OF THE IMMUNIZATION PROGRAMME AND HEALTH SYSTEM.
Describe the following 3 characteristics of the VACCINE.
- Vaccine safety
- Vaccine efficacy
- Vaccine effectiveness
State factors affecting vaccine effectiveness.
Vaccine safety- the type and likelihood of adverse events.
The safety of a new vaccine is assessed in clinical trials before it can be licensed.
Post-marketing surveillance may be needed to further establish the vaccine’s safety profile.
- Vaccine efficacy-
% reduction of the disease incidence in a vaccinated group compared to an unvaccinated group under optimal conditions- clinical trials.
- Vaccine effectiveness-
ability of the vaccine to prevent outcomes of interest in the ‘’real world’’.
Factors affecting VE: age, comorbidities, prior exposure, time since vaccination and immunization program performance.
Characteristics of available vaccine products
Programmatic and financial implications
Number of doses required, formulation, packaging and storage
Availability of vaccine supply: Global shortages and stock-outs of new vaccines. May need to delay introducing the vaccine or adopt a phased introduction strategy.
Disease the disease aspect that motivated the COVID 19 vaccine in Botswana.
The disease
- highly infections
- Public Health Emergency of National Concern, global & local Priority
- preventive and control measures behavior dependent
- Health and Economic impact
The vaccines
Undergone clinical trials, safety and efficacy
Disease the vaccine aspect that motivated the COVID 19 vaccine in Botswana.
The vaccines
Undergone clinical trials, safety and efficacy
Disease the health care system aspect that motivated the COVID 19 vaccine in Botswana.
The health system
An existing EPI program even in hard to reach areas
- Government funded
- cold chain management system
- A pool of HCW trained on EPI
- monitoring of Adverse Events Following Immunization (AEFI)
- surveillance of vaccine preventable diseases and immunization coverage
Phased introduction: vulnerable group- under 5s, elderly, comorbidity
What is herd immunity?
What is one of the aims with working towards herd immunity?
is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection.
Not recommended to achieve herd immunity through disease.
Herd immunity occurswhen a large portion of a community (the herd) becomes immune to a disease, making the spread of disease from person to person unlikely, breaking any chains of transmission.
Vaccines work effectively at a certain threshold of herd immunity
E.g. measles requires 95% of the population to be vaccinated
This guides vaccination
One of the aims with working towards herd immunity is to keepvulnerable groups who cannot get vaccinated(e.g. due to health conditions like allergic reactions to the vaccine/ immunocompromised) safeand protectedfrom the disease
State the vaccines given to children at birth.
*BCG
*Hepatitis B
