Vaccine and Immunization in Pediatrics

1. Basic Concepts

Definition and Purpose

• Red Book 2021, p 128

Types of Vaccines

2. Immunization Schedule

Age Indications - Key Principles

• Vaccines are given at the youngest safe age at which the child is at risk and can respond
• For parenterally-administered live vaccines in infants, residual maternal antibody determines optimal age (e.g., MMR given at 9-12 months because transplacentally acquired maternal antibody interferes with seroconversion before this age)
• Red Book 2021, p 128

US Recommended Schedule (ACIP / AAP / AAFP)

• Red Book 2021, Recommended Child and Adolescent Immunization Schedule for Ages ≤18 Years

National Immunization Schedule - India (IAP Recommended)

• Park's Textbook, Table 43

WHO EPI Schedule

3. Multiple Doses and Combination Vaccines

• Some vaccines require a series because no single dose gives full protection - e.g., one dose of MMR is 93% effective against measles and 78% against mumps; the second dose raises mumps protection to ~88%
• Protection from some vaccines (e.g., tetanus, diphtheria toxoids) wanes over time, requiring booster doses
• For a multidose series, recommended intervals optimize immunologic response and minimize adverse reactions (e.g., increased local reactions with DT/TT given too close together)
• Different vaccines given at the same visit are generally safe and effective and reduce the number of clinic visits. More than 1 live-virus vaccine (e.g., MMR and varicella) may be given simultaneously
• If 2 parenterally-administered live vaccines are not given simultaneously, they must be separated by ≥28 days to avoid immune interference
• Red Book 2021, pp 128-131

4. Lapsed Immunizations and Catch-Up

• A lapsed series does NOT require restarting - administer the missed dose at the next opportunity and continue the series from where it left off
• Rotavirus is the exception: series cannot start at or after 15 weeks, 0 days; final dose must not be given after 8 months, 0 days
• Children aged 6 months-8 years receiving influenza vaccine for the first time should receive 2 doses ≥4 weeks apart
• Unknown immunization status: treat as susceptible and begin age-appropriate schedule without delay. Serologic testing is an alternative for some antigens
• Red Book 2021, pp 138-139

5. Cold Chain

• Most vaccines: +2°C to +8°C
• Freeze-dried vaccines: may be stored frozen initially; rapidly lose potency after reconstitution

• Cholera, DPT/DTaP, Hepatitis B, Hib (liquid), HPV, IPV, Influenza, Pneumococcal, Tetanus/DT/Td

• Opened multi-dose vials without preservative must be kept at 2-8°C during the session or discarded within 4 hours after opening

• Park's Textbook, Cold Chain section

Open Vial Policy

1. The expiry date has not passed
2. Vaccines are stored under appropriate temperature throughout
3. Aseptic technique was maintained

6. Contraindications and Precautions

Contraindication

• Universal contraindication (all vaccines): History of anaphylaxis to a previous dose or to a vaccine component (unless desensitization has been performed)
• Severe allergic reaction (e.g., anaphylaxis) to any component of DTaP/Tdap is a contraindication to all diphtheria/tetanus-containing vaccines
• Red Book 2021, Guide to Contraindications and Precautions

Precaution

Specific Contraindications

• Live vaccines (MMR, Varicella, LAIV, etc.): contraindicated in severely immunocompromised patients (see below)
• MMR: moderate-severe febrile illness, recent blood product/IVIG administration (varies by product - check timing table), pregnancy
• Pertussis vaccine: history of encephalopathy within 7 days of prior dose (without other identifiable cause) is a contraindication to further pertussis antigen doses
• Inadvertent administration of Tdap instead of DTaP in a child <7 years: does NOT count as a valid dose 1, 2, or 3; but can be counted as valid dose 4 or 5

7. Vaccine Safety and Adverse Events

Classification of Adverse Events (Evidence of Causality)

• Red Book 2021, pp 143-147

Vaccine Adverse Event Reporting System (VAERS)

• A national passive surveillance system co-administered by CDC and FDA
• Reports suspected adverse events occurring in temporal association with vaccine administration
• Limitations: underreporting, stimulated reporting, no denominator data, no unvaccinated comparison group - cannot determine causality from VAERS alone
• The National Childhood Vaccine Injury Act (1986) requires health care providers to maintain permanent vaccination records and report listed events

National Childhood Immunization Schedule Safety

8. Immunization in Special Populations

Immunocompromised Children

• Generally contraindicated in severely immunocompromised children - vaccine strains can cause disease
• Exceptions exist for specific immune deficiency disorders where benefits outweigh risks (see Red Book Table 1.17)

• Do NOT convey substantial increased risk vs. immunocompetent children
• However, inactivated vaccines given during immunosuppression are generally not counted as valid doses
• Annual inactivated influenza vaccine (IIV) is recommended for all immunocompromised patients ≥6 months
• Special indications in immunocompromised: PCV13 → PPSV23, MenACWY (from infancy), MenB (from age 10), Hib (even after age 5)

• Timing of live vaccine resumption varies: as early as 3 months after stopping chemotherapy for acute leukemia, up to 24+ months after HSCT
• Rituximab (anti-CD20): prolonged immunodeficiency; vaccine response unlikely for at least 6 months
• Red Book 2021, pp 195-196

Children in Childcare/School Settings

• US relies on child care and school entry vaccine requirements to sustain high coverage
• All states require immunization for school entry
• AAP views non-medical exemptions as inappropriate for individual, public health, and ethical reasons

Immunization in Pregnancy (Maternal Vaccines)

• Recommended each season: Inactivated influenza vaccine
• Tdap: Recommended in each pregnancy (27-36 weeks) to protect newborn via maternal antibodies
• Contraindicated in pregnancy: Live vaccines (MMR, Varicella, LAIV, yellow fever - unless high-risk exposure)
• Note: Live oral/intranasal vaccines (LAIV, RV, Ty21A typhoid) do not need deferral after parenteral antibody products (IVIG/blood products), as antibodies do not reach mucosal surfaces in significant concentrations

9. Immune Globulin and Vaccine Timing

• Blood products/IVIG can interfere with the immune response to parenterally administered live vaccines (especially MMR, varicella)
• Required delay between blood product and live vaccine: varies by product and dose (range: 3-11 months for IVIG)
• Estimated antibody half-life ~30 days
• Live mucosal vaccines (LAIV, OPV, oral typhoid) are not affected and do not need deferral after blood products

10. Key Vaccines - Individual Summary

11. Monitoring and Documentation

• Permanent vaccination records are legally required under the National Childhood Vaccine Injury Act
• State-based immunization information systems (IIS) track vaccination history
• Unknown vaccination history: start age-appropriate schedule without delay
• Only written/electronic, dated, authentic records should be accepted as evidence of prior vaccination; parent recall is not sufficient

• Red Book 2021: Report of the Committee on Infectious Diseases, AAP (26th edition), pp 128-149, 195-196
• Park's Textbook of Preventive and Social Medicine, Tables 43-44 (National Immunization Schedule), Cold Chain section

National Health Programmes - India (Immunization & Child Health Focus)

1. Historical Milestones in India's Immunization Programme

2. Expanded Programme on Immunization (EPI) - 1978

• Launched by Government of India in 1978
• Objective: reduce mortality and morbidity from vaccine-preventable childhood diseases
• Original vaccines: BCG, DPT, OPV, Typhoid (urban areas)
• "Expanded" meant: adding more disease-controlling antigens, extending geographic coverage, and reaching less privileged sectors

3. Universal Immunization Programme (UIP) - 1985

Launch and Background

• UNICEF renamed EPI as "Universal Child Immunization (UCI)" in 1985
• India's version - the Universal Immunization Programme - launched 19 November 1985
• Goal: achieve universal immunization coverage of the eligible population by 1990
• EPI is regarded as the instrument of UCI

Target

1. Immunization of pregnant women against tetanus
2. Immunization of children in their first year of life

Programme Evolution

• 1992: UIP became part of CSSM
• 1997: UIP became part of RCH Programme
• Currently: UIP is a component of the National Health Mission (NHM)

National Immunization Schedule (UIP)

Pentavalent vaccine has replaced separate DPT, Hepatitis B, and Hib conjugate vaccines in the National Immunization Schedule - do not give these separately if pentavalent is being used.

4. Mission Indradhanush - 2014

• Launched: December 2014 by Ministry of Health & Family Welfare
• Named after the 7 colours of the rainbow (depicting 7 vaccines originally targeted)
• Goal: Fully immunize 90% of children who are either unvaccinated or partially vaccinated - those missed during routine immunization rounds - originally by 2020, target preponed to 2018

Target Beneficiaries

• Children who missed routine immunization
• Unvaccinated/partially vaccinated children
• Children in difficult-to-reach areas

Achievements (up to 6 phases, April 2015 - Dec 2018)

• Covered 681 districts
• 3.39 crore children reached
• 81.79 lakh children immunized
• 87.18 lakh pregnant women immunized
• First two phases: 6.7% increase in full immunization coverage in one year (vs. only 1% previously)
• Increase was more in rural areas (7.9%) than urban areas (3.1%)

Intensified Mission Indradhanush (IMI)

• 190 districts/urban areas across 24 states identified for intensification
• Special focus on urban areas after analysis showed lag there

5. Introduction of New Vaccines Under UIP

Japanese Encephalitis (JE) Vaccine - 2006

• Programme introduced to cover 104 endemic districts in phased manner
• Vaccine: SA 14-14-2 strain (imported from China)
• Initially: single dose to all children 1-15 years through campaigns
• Later integrated into routine immunization: 2 doses at 9-12 months and 16-24 months
• 21 high-burden districts in Assam, UP, and West Bengal identified for adult JE vaccination (15-65 years)

Rotavirus Vaccine - 2016

• Introduced in Odisha, Himachal Pradesh, Haryana, and Andhra Pradesh in 2016; later expanded
• Given under UIP as 3-dose vaccine alongside pentavalent 1st, 2nd, and 3rd doses

Rubella/MR Vaccine

• Initiated as Measles-Rubella (MR) campaign targeting age 9 months to 15 years in phased manner over 3 years
• Subsequently, MR vaccine introduced as 2 doses in place of measles-only vaccine at 9-12 months and 16-24 months (per NTAGI recommendations)

Pneumococcal Conjugate Vaccine (PCV)

• Introduced phased into routine immunization schedule

6. Child Survival and Safe Motherhood Programme (CSSM) - 1992

• Launched 1992
• Integrated UIP, oral rehydration therapy, and safe motherhood interventions
• Major components:
  • Child survival: immunization, Vitamin A, ORT, prevention of pneumonia deaths
  • Safe motherhood: ANC, TT immunization, safe delivery, anaemia control

7. Reproductive and Child Health (RCH) Programme - 1997

RCH Phase I - 1997 (formally launched 15 October 1997)

• Incorporated child survival and safe motherhood components
• Added STD and RTI components
• Differential approach: districts categorized A (58 districts), B (184 districts), C (265 districts) based on crude birth rate and female literacy rate
• Universal interventions:
  • Immunization, Vitamin A, ORT, pneumonia prevention
  • Antenatal care, TT immunization, safe delivery, anaemia control
  • Target Free Approach
  • RCH package for urban slums and tribal areas
  • RTI/STD clinics at district hospitals

RCH Phase II - 2005

• Integrated into NRHM
• Public-Private Partnership (PPP) to make programme more effective

8. National Rural Health Mission (NRHM) - 2005

• Launched: 5 April 2005 for 7 years (2005-2012), later extended to 2017
• Goal: improve rural health care delivery and bridge the gap through community-level workers

Focus States (18 states)

• 8 Empowered Action Group (EAG) states: Bihar, Jharkhand, Madhya Pradesh, Chhattisgarh, UP, Uttarakhand, Odisha, Rajasthan
• 8 North-East states: Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura
• Himachal Pradesh and Jammu & Kashmir

Core Strategy

• Accessible, affordable, accountable, effective, reliable primary health care
• Creation of ASHA (Accredited Social Health Activist) cadre - the cornerstone of NRHM
• Integration of multiple vertical programmes at district level
• Synergistic approach linking health with nutrition, sanitation, hygiene, and safe drinking water
• Mainstream integration of AYUSH (Ayurveda, Yoga, Unani, Siddha, Homeopathy)

Programmes Integrated into NRHM

1. RCH II
2. National Vector Borne Disease Control Programme (malaria, filaria, kala-azar, dengue, JE)
3. National Leprosy Eradication Programme
4. Revised National TB Control Programme (RNTCP)
5. National Programme for Control of Blindness
6. Iodine Deficiency Disorder Control Programme
7. Integrated Disease Surveillance Project (IDSP)

Key Initiatives Under NRHM

• Janani Suraksha Yojana (JSY): conditional cash transfer for institutional delivery
• Janani Shishu Suraksha Karyakram (JSSK): free delivery (including C-section) at public facilities - free drugs, diagnostics, blood, diet, referral transport
• Strengthening sub-centres with untied funds (Rs. 10,000/year for 18 focus states)
• Name-based web-enabled tracking of pregnant women
• Village Health and Nutrition Days (VHNDs) as outreach
• Mother and Child Protection (MCP) card

ASHA Role (Key Under NRHM)

• Community health activist between community and health system
• Promotes institutional delivery, immunization, ORS use
• Receives performance-based incentives

9. National Health Mission (NHM) - 2013

• Approved: May 2013
• Overarching umbrella combining:
  • NRHM (National Rural Health Mission)
  • NUHM (National Urban Health Mission)

Three Programmatic Components

1. Health system strengthening in rural and urban areas
2. RMNCH+A: Reproductive, Maternal, Newborn, Child and Adolescent Health Strategy
3. Control of communicable and non-communicable diseases

Key Achievement

• Reduction in out-of-pocket health expenses from 72% to 60%

RMNCH+A Strategy (2013)

• Integrates care across the life-cycle continuum
• R: Reproductive health
• M: Maternal health
• N: Newborn health
• C: Child health
• H: Adolescent health
• +A: Adolescent health specifically targeted

10. National Urban Health Mission (NUHM) - 2013

• U-PHC (Urban Primary Health Centre): 1 per 50,000 population
• U-CHC (Urban Community Health Centre): 1 per 5 lakh population (100 beds) for metro cities

11. Ayushman Bharat Programme - 2018

Component 1: Health and Wellness Centres (HWCs)

• 1.5 lakh HWCs to bring healthcare closer to communities
• Comprehensive health care: maternal & child health, communicable diseases, NCD management
• NCDs initially: hypertension, diabetes, 3 common cancers (oral, breast, cervix)
• Incrementally adding: mental health, ENT, ophthalmology, oral health, geriatric/palliative, trauma care, Yoga
• Free essential drugs and diagnostic services
• Headed by Community Health Officer (CHO) - BSc/GNM nurse or Ayurveda practitioner with 6-month certificate in community health
• First HWC inaugurated: 14 April 2018, Bijapur district, Chhattisgarh

Component 2: Pradhan Mantri Jan Arogya Yojana (AB-PMJAY)

• Health coverage: up to Rs. 5 lakh per family per year
• Beneficiaries: 10.74 crore poor and vulnerable families
• Based on Socio-Economic Caste Census (SECC) data
• Provides secondary and tertiary hospital care

12. India Newborn Action Plan (INAP) - 2014

• Launched 2014 to address neonatal mortality
• Builds on NRHM and RMNCH+A Strategy
• Focuses on: skilled birth attendance, essential newborn care, management of sick newborns, prevention and treatment of neonatal sepsis

Summary: Key National Immunization-Specific Programmes