1. Basic concepts: active vs passive immunization, types of vaccines, herd immunity, cold chain.
2. National Immunization Schedule: birth through adolescence, including catch-up vaccination.
3. Individual vaccines: BCG, hepatitis B, OPV/IPV, DPT-containing vaccines, Hib, rotavirus, pneumococcal, measles-rubella/MMR, Japanese encephalitis, HPV, typhoid, influenza, and others.
4. Practical administration: dose, route, site, spacing, simultaneous administration, documentation.
5. Contraindications and precautions: true contraindications versus common myths.
6. Adverse events following immunization: expected minor reactions, serious events, initial management and reporting.
7. Special situations: preterm infants, malnutrition, missed doses, immunocompromised children, travel, pregnancy in household contacts.
8. Vaccine storage and cold chain.
9. Communication with parents: vaccine hesitancy and counseling.

1. Full National Immunization Schedule
2. All vaccines with dose-route-site-age
3. Contraindications, AEFI, and cold chain
4. Special situations and catch-up vaccination

1. Principles of immunization
   • Active and passive immunization
   • Live and inactivated vaccines
   • Herd immunity, vaccine efficacy/effectiveness
   • Combination vaccines and simultaneous administration
2. India National Immunization Schedule
   • Birth to 16 years
   • Age, dose, route, site, and disease prevented
   • UIP vaccines and commonly recommended optional vaccines
3. Individual vaccine notes
   • BCG, hepatitis B, OPV, IPV, pentavalent/DPT, Hib
   • Rotavirus, PCV, MR/MMR, JE
   • Typhoid, hepatitis A, influenza, HPV, varicella, rabies, meningococcal vaccines
4. Catch-up immunization
   • Missed doses
   • Minimum ages and minimum intervals
   • Rules for interrupted schedules
5. Contraindications and precautions
   • True contraindications
   • False contraindications, such as mild fever, cough/cold, malnutrition, breastfeeding, and antibiotic use
6. AEFI
   • Expected local/systemic reactions
   • Anaphylaxis and emergency management
   • Reporting and observation after vaccination
7. Cold chain and vaccine handling
   • Temperature requirements
   • Vaccine vial monitor
   • Open-vial policy
   • Freeze-sensitive vaccines and shake test
8. Special situations
   • Preterm and low-birth-weight infants
   • Immunodeficiency/HIV
   • Children on steroids, chemotherapy, or biological agents
   • Household contacts of immunocompromised children
   • Travel immunization

Immunization in Children: Principles and Individual Vaccines

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1. Basic principles of immunization

Definition

• Park’s Textbook of Preventive and Social Medicine, chapter on Vaccines.

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2. Types of immunization

A. Active immunization

• Protection develops after a lag period, usually days to weeks.
• Produces immunological memory.
• Usually long-lasting.
• Booster doses may be needed.
• Given by vaccines or following natural infection.

• BCG
• Hepatitis B vaccine
• DPT/pentavalent vaccine
• MR/MMR
• IPV
• PCV
• HPV vaccine

B. Passive immunization

• Protection is immediate.
• Protection is temporary because no immune memory develops.
• Used for post-exposure prophylaxis, toxin neutralization, or in immunodeficiency.

1. Human normal immunoglobulin
2. Specific/hyperimmune immunoglobulin
   • Hepatitis B immunoglobulin (HBIG)
   • Rabies immunoglobulin (RIG)
   • Tetanus immunoglobulin (TIG)
   • Varicella-zoster immunoglobulin
3. Antisera/antitoxins
   • Diphtheria antitoxin
   • Botulinum antitoxin
   • Snake antivenom
4. Maternal antibody transfer
   • IgG through placenta
   • Secretory IgA in breast milk

C. Combined active and passive immunization

• Rabies exposure: rabies vaccine + RIG for category III exposure
• Tetanus-prone wound in inadequately immunized child: tetanus vaccine-containing preparation + TIG when indicated
• Infant born to an HBsAg-positive mother: hepatitis B vaccine + HBIG

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3. Classification of vaccines

• The Harriet Lane Handbook, “Immunoprophylaxis.”
• Park’s Textbook of Preventive and Social Medicine, chapter on Vaccines.

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4. Herd immunity

Importance

• Protects infants too young to receive vaccines.
• Protects people with severe immunodeficiency who cannot receive live vaccines.
• Protects those in whom vaccination did not produce adequate immunity.
• Helps eliminate or eradicate diseases.

Factors affecting herd immunity

• Vaccine effectiveness
• Vaccine coverage
• Infectiousness of disease, expressed as the basic reproduction number, R₀
• Duration of immunity
• Population movement and clustering of unvaccinated individuals

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5. General rules of vaccination

Simultaneous administration

• Multiple vaccines due at one visit should be given on the same day.
• Use separate syringes and separate sites.
• Do not mix vaccines in the same syringe unless supplied as a licensed combination product.
• This improves completion of the schedule and does not overload the immune system.

Spacing live vaccines

• Two injectable/nasal live vaccines should be given:
  • on the same day, or
  • separated by at least 4 weeks if not given together.

Interrupted schedules

• Never restart a vaccine series because of delay.
• Give the missed dose as soon as possible, observing the required minimum interval.

Mild illness is not a contraindication

• Mild fever
• Common cold/cough
• Diarrhea without severe dehydration
• Malnutrition
• Breastfeeding
• Stable neurological disease
• Treatment with antibiotics
• Prematurity

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6. Individual vaccines

A. BCG vaccine

Adverse effects

• Local papule, ulcer, and scar are expected.
• Regional axillary lymphadenitis may occur.
• Rare: suppurative lymphadenitis, osteitis, disseminated BCG infection.

Contraindications

• Severe primary immunodeficiency
• Severe cellular immunodeficiency
• Child on significant immunosuppressive therapy
• Symptomatic HIV infection or known severe immunosuppression, according to national guidance

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B. Hepatitis B vaccine

Important points

• The birth dose is particularly important for prevention of mother-to-child transmission.
• Preterm and low-birth-weight babies should receive the birth dose according to national policy.
• If mother is HBsAg-positive, give hepatitis B vaccine plus HBIG as soon as possible, ideally within 12 hours, at different sites.

Adverse effects

• Mild pain, redness, fever
• Anaphylaxis is extremely rare.

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C. Poliovirus vaccines

1. Oral polio vaccine (OPV)

2. Inactivated polio vaccine (IPV/fIPV)

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D. DPT-containing vaccines and pentavalent vaccine

Components

• D: Diphtheria toxoid
• P: Pertussis vaccine, whole-cell or acellular
• T: Tetanus toxoid

• DPT
• Hepatitis B
• Hib

Diseases prevented

• Diphtheria
• Pertussis
• Tetanus
• Hepatitis B
• Invasive Hib disease

Expected adverse effects

• Pain, redness, swelling
• Fever, irritability
• Persistent crying may occur, especially with whole-cell pertussis vaccine.

Important precautions

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E. Haemophilus influenzae type b vaccine (Hib)

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F. Rotavirus vaccine (RVV)

Key points

• Give orally. If the child spits out or regurgitates the dose, do not repeat it.
• Do not delay unnecessarily because rotavirus products have upper age limits.
• Contraindications include severe combined immunodeficiency and past intussusception.
• A small increased risk of intussusception has been reported after some rotavirus vaccines, but the benefits in preventing severe diarrheal disease are far greater.

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G. Pneumococcal conjugate vaccine (PCV)

High-risk children

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H. Measles-rubella vaccine (MR)

Importance

• Measles can cause pneumonia, diarrhea, encephalitis, malnutrition, blindness, and death.
• Rubella infection during pregnancy can lead to congenital rubella syndrome. Childhood vaccination helps prevent this.

Adverse effects

• Fever, mild rash, transient lymphadenopathy
• Febrile seizures may occur rarely.
• Thrombocytopenia is rare.

Contraindications

• Pregnancy
• Severe immunodeficiency
• Previous anaphylaxis to a vaccine component
• Defer after some immunoglobulin or blood-product exposures, because passively acquired antibody can reduce response.

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I. MMR vaccine

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J. Japanese encephalitis vaccine

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K. DPT booster and Td vaccine

DPT booster

Td vaccine

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7. Additional commonly recommended vaccines

A. Hepatitis A vaccine

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B. Typhoid conjugate vaccine (TCV)

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C. Influenza vaccine

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D. Varicella vaccine

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E. Human papillomavirus vaccine (HPV)

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F. Meningococcal vaccine

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G. Rabies vaccine

After animal bite/exposure

• Immediate and thorough wound washing with soap and running water for at least 15 minutes.
• Prompt medical assessment.
• Rabies vaccine for category II and III exposures.
• Rabies immunoglobulin for category III exposure, infiltrated into/around wounds whenever anatomically feasible.

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8. True contraindications versus false contraindications

Important true contraindications

Conditions that are usually not contraindications

• Mild fever or common cold
• Mild diarrhea
• Antibiotic use
• Breastfeeding
• Prematurity
• Low birth weight
• Malnutrition
• Family history of seizures
• Stable neurological disorder
• Controlled asthma or allergy
• Non-anaphylactic egg allergy for most routinely used vaccines

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9. Key counseling points for parents

1. Vaccines are given according to age because young children are at greatest risk of severe infection.
2. Mild fever, pain, irritability, and swelling after vaccination are common and usually settle within 1-2 days.
3. Bring the immunization card to every health visit.
4. If doses were missed, return promptly. The schedule can be continued; it usually does not need restarting.
5. Seek urgent care for breathing difficulty, facial swelling, persistent lethargy, seizures, persistent inconsolable crying, high fever, or signs of anaphylaxis after vaccination.
6. Continue breastfeeding and normal feeding after vaccination.
7. Oral polio drops should still be taken during Pulse Polio rounds even if the child has received routine OPV/IPV doses.