Vaccines and Immunization Overview

Vaccines

• Vaccines are actions to prevent diseases.
• Actions aim to eradicate or minimize disease and disability impact, or retard progress.
• Primary prevention stops disease development.
• Secondary prevention identifies people with disease onset but no symptoms.
• Tertiary prevention prevents complications in diagnosed individuals.

Edward Jenner

• In 1796, Jenner inserted cowpox into a boy to prevent smallpox.
• The boy became immune to smallpox.
• Jenner called this new method "vaccination."

Immunization

• Immunization makes a person immune to infectious diseases.
• Active immunization uses vaccines to stimulate immune responses.
• Passive immunization uses antibodies to create temporary immunity.
• Immunoglobulin is a fraction of human blood plasma with antibodies.
• Antitoxin is a solution of antibodies to specific antigens.
• Toxoids are modified toxins, non-toxic but stimulate antitoxin formation.
• Vaccines are preparations to create disease immunity by stimulating antibody production.

Vaccine Types

• There are various vaccine types, each designed to teach the immune system to fight germs.
• Scientists consider immune system response, targeted individuals, and best technology when creating vaccines.
• Four main vaccine types: live-attenuated, inactivated, subunit/recombinant/polysaccharide/conjugate, and toxoid.

Live-Attenuated Vaccines

• Contain weakened live bacteria or viruses replicating in the body.
• Examples include BCG, oral polio, and MMR.
• Create strong, long-lasting immunity.
• Usually require only 1 or 2 doses for lifetime protection.
• Limitations include weakened immune systems, long-term health problems, or organ transplants.
• Used to protect against measles, mumps, rubella, rotavirus, smallpox, chickenpox, yellow fever, and oral polio.

Inactivated Vaccines

• Use killed versions of disease-causing germs.
• Usually do not provide as strong immunity as live vaccines, needing boosters.
• Examples include hepatitis A, flu, polio (injectable type), and rabies.

Subunit, Recombinant, Polysaccharide, and Conjugate Vaccines

• Use specific pieces of the germ (protein, sugar, capsid).
• Produce strong, targeted immune responses.
• Effective for most people including those with compromised immune systems.
• May need boosters for ongoing protection.
• Used to protect against Hib, Hepatitis B, HPV, whooping cough, pneumococcal disease, and shingles.

Toxoid Vaccines

• Use toxins (harmful products) made by disease-causing germs.
• Target the toxin, not the whole germ.
• Create immunity against the toxin, not the whole disease.
• Require boosters like other types to maintain ongoing protection.
• Examples: diphtheria and tetanus.

Vaccine Administration

• Different routes of vaccine administration exist; the optimal route depends on the vaccine type.
• Key vaccine administration sites include deltoid muscle, vastus lateralis muscle, and other injection sites.

Vaccine Safety and Quality

• Vaccines are sensitive to heat and freezing.
• Vaccine storage and transport require the cold-chain system.
• VVM monitoring is vital for the cold-chain.

Storing Vaccines

• WHO recommends specific temperature ranges for storage and transport based on manufacturer data.
• All vaccines can be stored at positive temperatures (2°C to 8°C).
• Some vaccines can be stored at negative temperatures (-15°C to -25°C).

Vaccine Monitoring

• Daily and monthly vaccine checking and recording are essential.
• Cold box monitoring is essential for quality vaccine storage.

Vaccine Vial Monitors (VVMs)

• VVM are chemical indicators attached to vaccine vials, ampoules, and droppers
• VVMs track heat exposure.
• VVM coloration changes as heat exposure increases.
• A lighter square indicates safe temperatures; a darker square indicates discard.

Iraq Data

• Iraq's immunization program (EPI) began in 1985.

• The program targets specific groups.

• The long-term vision is complete, high-quality services for all.

• Iraq has diverse demographic data including population totals, children, infants, and pregnant women in 2024

• Data for various vaccines (polio and measles) over time is recorded to show the changes.

• Various milestones like the launch of EPI, establishment of cold chain, introductions of MMR and new vaccines, and using PCV13 were covered

• Vaccination schedules vary depending on the year.

• Common vaccines were highlighted including bOPV, HepB, BCG, DPT, OPV, MCV, TT, MMR, Rotavirus, IPV, and others.