Immunisation Schedule & Vaccines

Immunisation is the single most cost-effective public-health intervention, and the Universal Immunisation Programme (UIP) is among the largest in the world. NEET PG loves precise recall here — exact ages of each antigen, cold-chain temperatures, the difference between Sabin and Salk, and contraindications. This chapter packages all of it.

Classification of vaccines

Vaccines are first divided by the nature of the immunising agent. This classification predicts storage, contraindications, and the cold chain.

Type	Examples (Indian programme & common)	Key behaviour
Live attenuated	BCG, OPV, Measles, MR/MMR, Rotavirus, JE (live SA-14-14-2), Yellow fever, Varicella, Typhoid (oral Ty21a)	Single dose often enough; contraindicated in pregnancy & immunocompromise; heat-sensitive
Killed / inactivated (whole organism)	IPV (Salk), Whole-cell Pertussis, Cholera, Rabies, JE (Vero-cell inactivated), Hepatitis A	Need multiple doses + adjuvant/booster
Toxoid	Diphtheria toxoid, Tetanus toxoid	Most heat-stable; aluminium-adjuvanted
Subunit / polysaccharide / conjugate	Hepatitis B (recombinant), PCV, Hib, Typhoid Vi, HPV, acellular Pertussis	Conjugation (to carrier protein) gives T-cell memory in <2 yrs

High-yield: Live vaccines that can usually be given together on the same day; if not given together, separate live parenteral vaccines by at least 4 weeks. OPV (live oral) can be given any time relative to other live vaccines.

A second useful split:

• First-generation: whole organism (live or killed).
• Second-generation: subunit, toxoid, polysaccharide, conjugate, recombinant (Hep B).
• Third-generation: DNA/mRNA and recombinant-vector vaccines.

National Immunisation Schedule (UIP) — ages for each antigen

This is the most frequently asked table. Learn it cold.

Age	Vaccines
Birth	BCG, OPV-0 (zero dose), Hepatitis B birth dose
6 weeks	OPV-1, Pentavalent-1 (DPT+HepB+Hib), Rotavirus-1, fIPV-1, PCV-1
10 weeks	OPV-2, Pentavalent-2, Rotavirus-2
14 weeks	OPV-3, Pentavalent-3, Rotavirus-3, fIPV-2, PCV-2
9–12 months	MR-1 (measles-rubella), JE-1*, PCV-booster, Vitamin A 1st dose
16–24 months	MR-2, JE-2*, DPT-booster-1, OPV-booster
5–6 years	DPT-booster-2
10 years	Td (tetanus + reduced diphtheria)
16 years	Td
Pregnancy	Td-1, Td-2 (or a Td booster if previously immunised)

*JE only in endemic districts. Note that DPT has replaced "TT" with "Td" at 10 and 16 years and in pregnancy (a reduced-diphtheria toxoid is now used to maintain diphtheria immunity).

High-yield: BCG, OPV-0 and Hep-B birth dose are the three birth vaccines. If BCG is missed it can be given up to 1 year of age (after that, the tuberculin reaction is unpredictable — give without testing up to 5 yrs in many guidelines, but classically "up to 1 year" is the UIP answer).

High-yield: Fractional IPV (fIPV) is given intradermally (0.1 mL) at 6 and 14 weeks; full IPV is 0.5 mL intramuscular. India switched from tOPV to bivalent OPV (type 1 & 3) in April 2016 after global withdrawal of type-2 component, and added IPV to cover poliovirus type 2.

Vitamin A schedule (linked to immunisation contacts): 1st dose 1 lakh IU at 9 months with MR-1, then 2 lakh IU every 6 months up to 5 years (total 9 doses).

Cold chain — temperatures & equipment

The cold chain is the system of storing and transporting vaccines within a safe temperature range from manufacturer to beneficiary.

Level	Equipment	Temperature
Primary/regional store	Walk-in cooler (WIC)	+2 to +8 °C
Regional store (freezing)	Walk-in freezer (WIF)	−15 to −25 °C
PHC / district	ILR (Ice-Lined Refrigerator)	+2 to +8 °C
PHC / district	Deep freezer (DF)	−18 to −20 °C (≈ −15 to −25)
Field / transport	Cold box, vaccine carrier (with ice packs)	+2 to +8 °C

High-yield: ILR keeps OPV-type heat-sensitive vaccines and refrigerated items at +2 to +8 °C; the deep freezer (−18 to −20 °C) is used to make ice packs and to store OPV at the higher levels. At PHC level OPV is kept in the deep freezer; at the sub-centre/field it is in the vaccine carrier.

Order of heat sensitivity (most → least): OPV > Measles/MR > BCG (reconstituted) > DPT/Hep B/TT > diluents.

Order of freeze sensitivity (must NOT be frozen): DPT, Pentavalent, Hep B, IPV, PCV, TT/Td — these are aluminium-adjuvanted and are destroyed by freezing.

High-yield: The "shake test" detects a freeze-damaged adsorbed vaccine (DPT/Hep B/TT): a frozen-and-thawed vial sediments faster and shows flakes, compared with a smooth never-frozen vial.

Vaccine Vial Monitor (VVM)

A heat-sensitive square inside a circle on the label. As long as the inner square is lighter than the outer ring, the vaccine is usable. When the square matches or is darker than the ring, discard. The VVM is present mainly on OPV (most heat-labile).

Open Vial Policy (multi-dose)

Reconstituted BCG and Measles/MR must be discarded after 4 hours. Liquid vaccines without preservative issues (OPV, DPT, TT/Td, Hep B, Pentavalent) opened in a session can be used in subsequent sessions up to 4 weeks if conditions are met (VVM ok, stored at 2–8 °C, not expired, not contaminated).

OPV vs IPV — Sabin vs Salk

A perennial favourite.

Feature	OPV (Sabin)	IPV (Salk)
Nature	Live attenuated	Killed / inactivated
Route	Oral	Intramuscular / intradermal (fIPV)
Immunity	Both intestinal (mucosal IgA) + humoral	Mainly humoral (IgG), poor gut immunity
Herd immunity	Yes (secondary spread of vaccine virus)	No
VAPP / VDPV	Yes — risk of vaccine-associated paralytic polio & circulating vaccine-derived poliovirus	No risk
Use in immunocompromised	Contraindicated	Safe
Cost / storage	Cheap, but very heat-labile	Costlier, more stable
Suited for	Mass campaigns, eradication	Routine where wild virus eliminated

High-yield: VAPP occurs roughly 1 per 2.4–2.7 million doses (highest with the first dose). The eventual global aim is to phase out OPV entirely (because OPV is now the only source of paralytic polio in many regions) and shift to IPV-only schedules.

Pulse Polio Immunisation (PPI) — rationale

India was certified polio-free in March 2014 (last wild case Jan 2011, Howrah). Pulse Polio strategy underpinned this.

Why pulse, not just routine? Routine OPV alone left pockets of susceptible children. PPI gives two national immunisation days (NIDs) per year to all children <5 years, regardless of prior immunisation status, to:

1. Rapidly flood the community with vaccine virus so it out-competes any circulating wild poliovirus.
2. Interrupt transmission by simultaneously immunising the whole susceptible cohort in a short window.
3. Boost both individual and herd intestinal immunity.

Stepwise eradication logic: High routine OPV coverage → supplementary PPI rounds → AFP (acute flaccid paralysis) surveillance with stool testing → mopping-up rounds in residual transmission areas → zero wild virus → certification.

High-yield: Any case of acute flaccid paralysis in a child <15 years must be reported and investigated — two stool samples within 14 days are collected for poliovirus isolation. The target non-polio AFP rate (a sensitivity indicator) is ≥2 per 100,000 children under 15.

Contraindications (vaccine-specific)

Most contraindications are over-stated in practice. Know the true ones.

Vaccine	True contraindication / caution
All live vaccines	Pregnancy, immunodeficiency/immunosuppression, high-dose steroids, recent IVIG/blood (defer live vaccine)
BCG	Symptomatic HIV/AIDS, generalised eczema, immunodeficiency
OPV	Immunodeficiency in child or household contact (use IPV)
DPT (whole-cell)	Encephalopathy within 7 days of prior dose; progressive neurological disease — switch to DT/DPaT (omit pertussis)
Measles/MR	Severe egg allergy (caution, not absolute), anaphylaxis to neomycin
Influenza/Yellow fever	Severe egg allergy
Any vaccine	Anaphylaxis to a previous dose or a vaccine component

Not contraindications (myths): minor illness with low-grade fever, mild diarrhoea, current antibiotic use, breastfeeding, prematurity, malnutrition, family history of convulsions, or a local reaction to a previous dose.

High-yield: In HIV-infected children, BCG is contraindicated if symptomatic; OPV is replaced by IPV; measles vaccine is given (and even an extra dose at 6 months) because measles is dangerous in HIV.

Newer UIP additions (recent expansions)

Examiners track these because the schedule keeps evolving.

• Hepatitis B — integrated into Pentavalent; birth dose to prevent perinatal transmission.
• Pentavalent (DPT + HepB + Hib) — Hib protects against Haemophilus influenzae type b meningitis/pneumonia.
• IPV / fIPV — added for poliovirus type-2 cover after bOPV switch.
• Rotavirus vaccine (RVV) — 3 oral doses at 6, 10, 14 weeks; prevents severe rotaviral gastroenteritis.
• PCV (Pneumococcal Conjugate Vaccine) — 6 wk, 14 wk + 9-month booster (2p+1 schedule); against Streptococcus pneumoniae.
• Measles–Rubella (MR) replaced standalone measles; goal of measles elimination and rubella/CRS control.
• JE vaccine — live SA-14-14-2 in endemic districts at 9 m & 16–24 m.
• Td replaced TT to sustain diphtheria immunity in adolescents and pregnant women.
• Rotavirus and PCV national roll-out, and adult/adolescent vaccines (e.g., HPV being introduced in phases) are the newest frontier.

High-yield: Mission Indradhanush (2014) and Intensified Mission Indradhanush (IMI) target full immunisation in low-coverage districts — aim ≥90% full immunisation coverage. "Full immunisation" classically = a child who has received BCG + 3 DPT + 3 OPV + measles by 1 year of age.

Tetanus prophylaxis in wound management

A classic clinical-prevention crossover question.

Approach: Assess (a) immunisation status and (b) wound type (clean-minor vs tetanus-prone).

1. Fully immunised, last booster <5 yrs ago → nothing needed.
2. Fully immunised, last booster 5–10 yrs → Td booster only if tetanus-prone wound.
3. Fully immunised, >10 yrs since booster → Td booster for any wound.
4. Incomplete / unknown status → complete Td series + give Tetanus Immunoglobulin (TIG, human) for tetanus-prone wounds.

High-yield: Human TIG dose = 250 IU IM (500 IU if delay >24 h, heavy contamination, or burns/heavy wounds). Always give active (toxoid) and passive (TIG) immunisation at different sites with different syringes.

Eponyms, named items & cut-offs to memorise

• Sabin = oral live polio (Albert Sabin); Salk = injectable killed polio (Jonas Salk).
• BCG = Bacille Calmette–Guérin (live attenuated M. bovis); dose 0.05 mL (newborn) / 0.1 mL intradermal over left deltoid; correct technique → wheal then a papule/scar in 6 weeks.
• Lübeck disaster — historic BCG contamination tragedy.
• Edmonston-Zagreb / Schwarz strains — measles vaccine strains.
• SA-14-14-2 — live JE vaccine strain.
• VVM, OVP, shake test — cold-chain QA tools (above).

Mnemonics

• Birth vaccines "BOH": BCG, OPV-0, Hep-B.
• Freeze-sensitive adjuvanted "PHD-TIP": Pentavalent, Hep B, DPT, TT/Td, IPV, PCV — never freeze these.
• Heat order "OM-BD": OPV > Measles > BCG(reconstituted) > DPT/TT.
• Live vaccine spacing: "live + live → same day or 4 weeks apart."

Recently asked / exam angle

• "Ice-Lined Refrigerator maintains what temperature?" → +2 to +8 °C (deep freezer −18 to −20 °C). Direct one-liner.
• "Which vaccine is given intradermally?" → BCG (and fIPV); the only routine ID injection in UIP is BCG.
• "Vaccine most sensitive to heat in cold chain?" → OPV.
• "Vaccine destroyed by freezing?" → adsorbed/adjuvanted ones — DPT, Hep B, TT/Td, IPV, PCV.
• "Age of first measles/MR dose?" → 9–12 months (second dose 16–24 months).
• "Sabin vs Salk" — live oral vs killed parenteral; herd immunity & VAPP only with Sabin.
• "Open vial policy — reconstituted BCG/measles discard time?" → 4 hours.
• "Td has replaced TT — why?" → to maintain diphtheria immunity in adolescents/pregnancy.
• "VVM usable when?" → inner square lighter than outer ring.
• "Non-polio AFP surveillance target rate?" → ≥2/100,000 <15 yrs.
• "Number of Vit A doses by 5 years?" → 9 doses (1 lakh IU first, then 2 lakh IU 6-monthly).
• Statement/assertion-reason questions on why pulse polio and on contraindications myths (mild fever is NOT a contraindication).

Rapid revision

1. Birth dose = BCG + OPV-0 + Hep-B (mnemonic BOH); BCG is intradermal 0.1 mL left deltoid.
2. 6, 10, 14 weeks = primary series: OPV + Pentavalent + Rotavirus (PCV & fIPV at 6 & 14 wk only).
3. MR-1 at 9 months, MR-2 at 16–24 months; measles vaccine is the second most heat-labile after OPV.
4. ILR = +2 to +8 °C; Deep Freezer = −18 to −20 °C. OPV is the most heat-sensitive vaccine.
5. Never freeze DPT, Hep B, TT/Td, IPV, PCV (adjuvanted) — detected by the shake test.
6. VVM on OPV: usable while inner square is lighter than outer ring.
7. Open-vial policy: reconstituted BCG & measles discarded in 4 hours; liquid multi-dose vaccines up to 4 weeks.
8. OPV (Sabin, live, oral) gives gut immunity + herd effect but causes VAPP/VDPV; IPV (Salk, killed, IM) is safe in immunocompromised, no herd immunity.
9. India is polio-free since 2014; Pulse Polio floods susceptibles to interrupt transmission; report all AFP <15 yrs with 2 stool samples in 14 days.
10. Td replaced TT at 10 yr, 16 yr & pregnancy to preserve diphtheria immunity.
11. In HIV: avoid symptomatic-stage BCG, replace OPV with IPV, but do give measles vaccine.
12. Human TIG 250 IU IM for tetanus-prone wounds in incomplete/unknown immunisation; mild fever/minor illness is never a contraindication to vaccination.