The Paediatric Immunisation Schedule: The Evidence Behind the Scheduler

It is a busy Tuesday immunisation session at a primary health centre near Kaup. A mother hands you her daughter’s card. The child is seven months old. The card shows the birth doses and the 6-week doses, and then nothing: the family moved for work and the visits stopped. The staff nurse asks, “Doctor, should we start the course again?” This is an illustrative case, not a real child.

By the end of this article you will know how to answer her, which vaccines the child can and cannot still have, where each injection goes, and what the five diseases in the first injection look like when the schedule fails.

1. Never Start Again

The answer to the nurse is no. Never restart a delayed vaccine series. Immunological memory does not lapse. The doses this child received at 6 weeks still count. So we pick the schedule up where it stopped, and we keep the standard minimum intervals between the doses that remain.

“Then can we give all the missing doses today, to catch up quickly?” Not all of them. The minimum interval between primary Pentavalent, OPV and rotavirus doses is strictly 4 weeks. A dose given earlier than that is invalid: it does not count, and the child is no better protected. So the next dose of each goes today, and the one after it no sooner than 4 weeks later. The scheduler lays out the dates for you from the child’s date of birth.

2. The One Vaccine With an Age Limit

Rotavirus vaccine is the exception that catches people out. The first dose must not be started after 14 weeks 6 days of age, and the series must be completed by 1 year. Our child had her first rotavirus dose at 6 weeks, so she may complete the series, provided it finishes before her first birthday.

A common mistake: treating rotavirus like every other missed vaccine and giving a first dose to a five-month-old who never had one. It is easy to see why: the interruption rule says never start again, and catching up feels right. But the age limit is a separate rule, and it wins. A child who has passed 14 weeks 6 days without a first dose does not get one.

3. The Five Diseases in One Injection

The liquid Pentavalent vaccine (DTwP-HepB-Hib) covers five diseases in one injection. Each of them still kills children in India, and each is preventable. Why learn what each one looks like? Because the child who arrives with one of them is usually a child the schedule missed, and recognising it early is the next best thing to having prevented it.

Notice two things. Pertussis in a neonate may not present with a cough at all: apnoea is the primary presentation. And “eliminated” for neonatal tetanus is a statement about mothers and newborns, not about an unvaccinated adult with a dirty wound.

4. Where Each Injection Goes

Now the nurse draws up the injections. The route decides the site, and the site is not a matter of habit.

• Intradermal (BCG, fIPV): BCG in the left upper arm, fIPV in the right upper arm, at 15° with the bevel up, producing a distinct pale wheal.
• Intramuscular (Pentavalent, PCV, HepB, the DPT boosters, Td, Tdap, TCV, IPV, HPV): the anterolateral mid-thigh in infants and toddlers, the deltoid after 3 years, at 90°, deep into the muscle.
• Subcutaneous (MR or MMR, JE, varicella): MR in the right upper arm and JE in the left, at 45° into pinched tissue.
• Oral (OPV, rotavirus vaccine, vitamin A, albendazole): if an infant regurgitates the OPV or rotavirus dose immediately, repeat it after 5 minutes.

“Why not the buttock? It is a big muscle.” In an infant the gluteal region is mostly fat, so absorption is erratic, and the sciatic nerve lies close. That is why the anterolateral mid-thigh is the only acceptable intramuscular site under 3 years. You will still see the buttock used, usually by staff who were taught it that way. Teach them kindly; the thigh is the safe place.

5. The Cold Chain, and Why Freezing Matters

Vaccines that freeze are ruined, and nothing about the vial will tell you by looking. The tool’s mnemonic is “Never Freeze P-H-D”: Pentavalent, PCV and polio (IPV or fIPV); Hepatitis B and Hib; DPT, DTaP and Td. Pentavalent, HepB, Td, DPT, PCV and IPV are adsorbed on aluminium adjuvants, and freezing destroys the adjuvant lattice irreversibly. If you suspect a vial has frozen, perform the shake test against a known frozen control.

Opened multi-dose liquid vaccines (OPV, HepB, DPT, Td, Pentavalent, PCV) can be used for up to 28 days if stored at +2 to +8 °C with the vaccine vial monitor intact. Reconstituted lyophilised vaccines (BCG, MR, JE) must be discarded within 4 hours.

Two more rules sit beside these. The live vaccines (BCG, rotavirus, OPV, measles, MR, MMR, mumps and varicella, and the live JE vaccine) are avoided in severe immunocompromise; and two injectable live vaccines are given either on the same day or at least 4 weeks apart. The birth doses (BCG, OPV-0 and the hepatitis B birth dose) belong in the first 24 hours: hepatitis B given later protects much less well against transmission from the mother.

6. Two Schedules, Neither Wrong

The mother asks whether her daughter should also have “the private vaccines” her sister’s child received. Here you need to know that India has two schedules. The National Immunization Schedule (NIS) is the government schedule under the Universal Immunization Programme: free, in the public sector, and built to protect a population. The Indian Academy of Pediatrics (IAP) schedule is written for private practice and adds vaccines the NIS does not carry: typhoid conjugate vaccine, influenza, hepatitis A and varicella, with MMR in place of MR.

Neither is a corrected version of the other. Record which one you have used, because it decides what counts as a complete schedule. The scheduler prints both side by side.

“Is the painless DPT better, then?” DTaP, the acellular vaccine, is marketed as painless and causes fewer reactions. The whole-cell DTwP in the Pentavalent confers more durable immunity. DTaP is acceptable, but not automatically superior; counsel the family objectively, and choose combinations on what the family can afford, not on marketing. And there is no evidence for annual typhoid “boosters”: a single dose of TCV protects for at least 5 years.

7. After the Injection

Most reactions are minor and expected: local pain or swelling, a low-grade fever under 38.5°C, irritability for 24 to 48 hours. Reassure the parents, give paracetamol 10 to 15 mg/kg as needed, and remember that a minor reaction is not a contraindication to the next dose. A high fever above 39°C, crying for more than 3 hours or a local reaction over 5 cm is documented and managed symptomatically; if the whole-cell vaccine caused it, consider DTaP for the future DPT doses.

A serious event is different: anaphylaxis within 30 minutes, a hypotonic-hyporesponsive episode, intussusception after rotavirus vaccine, or BCG-osis. Manage anaphylaxis with intramuscular adrenaline 0.01 ml/kg of 1:1000, admit the child, and report every serious AEFI within 24 hours to the District Immunization Officer. Never dismiss a parent’s worry about a reaction; document it in full.

Back to Our Patient

Nobody restarts anything. The child gets the next due dose of each primary series today, in the right sites, and the following doses are booked no sooner than 4 weeks later. Her rotavirus series continues, because she started it in time, and it must be finished before her first birthday. Her mother is told what to expect tonight and when to come back. And the card says which schedule was followed.

Try This

A boy of 16 weeks comes for his first immunisation visit since birth. He had BCG, OPV-0 and the hepatitis B birth dose, and nothing since. The intern plans the full set of 6-week vaccines, including rotavirus. What would you change? Illustrative case.

Answer. Leave out rotavirus. The first dose must not be started after 14 weeks 6 days, and he is past it. Everything else goes ahead from where he stopped, with the minimum interval of 4 weeks between primary doses from here on. His birth doses still count.

Take-Home Points

• Never restart a delayed series: pick up where it stopped, with at least 4 weeks between primary doses.
• Rotavirus has its own limits: no first dose after 14 weeks 6 days, and the series done by 1 year.
• Under 3 years, intramuscular vaccines go into the anterolateral mid-thigh, never the buttock.
• Never freeze P-H-D; discard reconstituted BCG, MR and JE within 4 hours.
• Report every serious AEFI within 24 hours, and record which schedule, NIS or IAP, you followed.

For the questions families ask about vaccine safety, see Doctor, Are Vaccines Really Safe? and Strategies for Combating the Anti-Vax Challenge. For vaccines in pregnancy and the antenatal visits, see Pregnancy Dating and the Antenatal Schedule: The Evidence Behind the Tool; for HPV and the cervix, Cervical Screening and the Abnormal Pap: The Evidence Behind the Pathway.

Declaration: the author built and maintains the tool. It is free to use. The figures in this article are those the tool carried in its Evidence tab on 5 November 2026, each from the source the tool names. The illustrative cases follow the tool’s rules; check the tool’s schedule for a real child.

References

1. Ministry of Health and Family Welfare, Government of India. Universal Immunization Programme: National Immunization Schedule. Immunization Division, MoHFW; 2024.
2. Indian Academy of Pediatrics, Advisory Committee on Vaccines and Immunization Practices (ACVIP). IAP Guidebook on Immunization 2023-2025. Eds: Kasi SG, et al. New Delhi: Jaypee Brothers; 2024.
3. Ministry of Health and Family Welfare. Immunization Handbook for Medical Officers. Government of India; 2017 (updated 2022).
4. World Health Organization. WHO Recommendations for Routine Immunization - Summary Tables. Geneva: WHO; 2024.
5. National Technical Advisory Group on Immunization (NTAGI), India. Recommendations on PCV and HPV Introduction in UIP. MoHFW; 2023.