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6–14 Week Vaccines

DPT Vaccine Side Effects in Babies & Children

Fever and a sore leg are the usual DPT reactions in babies; boosters in older children can swell the whole arm, which looks worse than it is.

🟢 Usually mild💉 Given: 6, 10 & 14 weeks + boosters (16–24 months, 4–6 years)⏳ Settles: 1–3 days⏱️ 7 min read🗓️ Updated 6 July 2026✅ 7 sources🩺 Medical review pending

Written and fact-checked by the ParentVibes editorial team against WHO, IAP, CDC and NHS immunisation guidance. Not yet reviewed by a named clinician.

Quick facts

Infant doses
6, 10 & 14 weeks (thigh)
Boosters
16–24 months & 4–6 years
Protects against
Diphtheria, pertussis, tetanus
Typical reaction
Fever + sore, swollen injection site
Usually settles in
2–3 days

DPT — the 'triple vaccine' — has protected children against diphtheria, whooping cough and tetanus for generations. In India it is given as three infant doses at 6, 10 and 14 weeks (often inside the pentavalent combination) and then as booster doses at 16–24 months and again at 4–6 years to top up waning immunity as your child grows.

DPT is one of the more reactive vaccines on the schedule, so a fever and a sore injection site are common and expected. What surprises many parents is the booster stage: the toddler and pre-school doses can cause a whole-limb swelling that looks dramatic. It is a well-recognised, self-limiting reaction — this guide explains what is normal at each age and the small number of signs that mean 'call now'.

What the DPT vaccine is

DPT is an inactivated vaccine that combines diphtheria and tetanus toxoids with a pertussis (whooping cough) component. It comes in two main forms. DTwP uses whole-cell pertussis — it gives strong protection and is widely used in India, but causes more fever and local soreness. DTaP uses acellular pertussis, which is gentler with fewer fever reactions and is often chosen for booster doses or for children who reacted strongly to DTwP.

Infant doses are given into the thigh; boosters in older children are usually given into the upper arm. Your paediatrician chooses the form and site based on your child's age and history.

DTwP vs DTaP in plain terms

Think of DTwP as the 'stronger reaction, robust protection' version and DTaP as the 'gentler' one. Both protect well — if your baby had a big reaction to a DTwP dose, ask your doctor whether DTaP suits the next one.

Common DPT side effects

Reactions usually begin within hours and settle over a few days. They tend to be more noticeable with the whole-cell (DTwP) form and at booster age.

Fever

A raised temperature within the first day is one of the most common DPT reactions, especially with the whole-cell form. It is usually mild to moderate and eases within a day or two.

A sore, red injection site

The thigh (in babies) or upper arm (in older children) becomes tender, red and warm. Your child may limp, favour the arm, or protest when the area is touched.

Swelling of the injection site — larger with boosters

Local swelling is common. At the toddler and 4–6 year booster doses, it can extend to involve much of the upper arm or thigh — a striking but recognised reaction that typically settles in a few days.

Irritability and fussiness

Babies are often cranky and clingy; older children may be out of sorts or reluctant to use the sore limb for a day or so.

Reduced feeding or appetite

A temporary dip in feeding (babies) or appetite (children) is common on the day of the shot and settles quickly.

Tiredness or extra sleepiness

Feeling drowsy and needing more rest for a day after the vaccine is a normal part of the immune response.

Fever relief the safe way

If your doctor advises it, give paracetamol in the dose matched to your child's weight. Never give aspirin to a child, and do not give ibuprofen to a baby under 3 months.

What's usually normal after DPT

The reaction differs a little by age, but these are all normal:

  • A mild to moderate fever in the first 24 hours, settling within a day or two.
  • A red, warm, tender injection site — the thigh in babies, the upper arm in older children.
  • Larger swelling of much of the limb after a booster dose, which looks alarming but usually settles in a few days.
  • A cranky, clingy baby, or an older child who limps or guards the sore arm briefly.
  • Extra tiredness, longer naps and a short-lived dip in feeding or appetite.
  • A small firm lump at the site that slowly fades over a week or two.
DoseWhat parents most often notice
6/10/14 weeksFever, sore thigh, fussiness, sleepiness
16–24 month boosterBigger local swelling, sore leg or arm, fever
4–6 year boosterWhole-arm swelling, soreness, tiredness

How long DPT side effects last

  • Fever: usually within the first 24 hours, settling over 1–2 days.
  • Soreness and redness at the site: typically ease over 2–3 days.
  • Larger booster-dose limb swelling: usually peaks within a day or two and settles within about 3–5 days.
  • Fussiness, tiredness and reduced appetite: normally gone by the second day.
  • A small firm lump at the site: can take 1–2 weeks to fully disappear.

Big booster swelling is usually benign

Extensive swelling of the arm or thigh after a booster is a known reaction that settles on its own. Get it checked, though, if the skin is hot and spreading, very painful, or your child is unwell with it.

Home care after the DPT vaccine

Comfort, gentle movement and simple fever care cover most of what's needed.

Fever & general comfort

  • Keep your child in light clothing and offer fluids often — feeds for babies, water or milk for older children.
  • If your doctor advises it, use paracetamol in the weight-appropriate dose; never aspirin, and no ibuprofen under 3 months.
  • Plenty of rest, cuddles and reassurance help a grumbly, feverish child feel better.
  • Keep the vaccination card updated so booster doses are given on time.

The sore limb

  • A clean, cool damp cloth on the site for a few minutes can ease soreness and swelling.
  • Encourage gentle, normal use of the arm or leg — keeping it moving helps, and rest is fine too.
  • Avoid pressing, massaging or applying balms and oils to the swollen area unless your doctor advises it.
  • For older children, a loose sleeve avoids rubbing the tender arm.

Warning signs — see a doctor urgently

Ordinary fever and soreness are expected. These signs need urgent medical review:

Seek urgent medical care if your child has

  • A very high fever of 40°C (104°F) or above.
  • A seizure (fit) — convulsing, stiffening or a blank, unresponsive spell.
  • Inconsolable, high-pitched crying that lasts more than 3 hours despite comforting.
  • A floppy, pale, limp and unresponsive episode, or a child who is very difficult to rouse.
  • Signs of a severe allergic reaction — trouble breathing, swelling of the face or lips, or hives all over — usually within minutes to an hour.
  • Injection-site swelling that spreads fast, is very hot and hard, or begins to drain pus.

Call your doctor immediately — or go straight to the nearest emergency department.

🩺 Find a paediatrician

Any seizure, breathing difficulty or floppy, unresponsive episode is an emergency — go to the nearest hospital straight away.

When to call your paediatrician

Not an emergency, but worth checking:

  • Fever that lasts beyond 48 hours or returns after settling.
  • Limb swelling that keeps growing after 2–3 days, stays hot, or is increasingly painful.
  • Your child won't use the arm or leg at all, or is in obvious ongoing pain.
  • Feeding or drinking stays poor, with fewer wet nappies than usual.
  • You want advice on whether the next dose should be DTaP after a strong DTwP reaction.

Frequently asked questions

What is the difference between DTwP and DTaP?

Both protect against diphtheria, tetanus and whooping cough. DTwP uses whole-cell pertussis — strong protection but more fever and soreness. DTaP uses acellular pertussis and is gentler. If your baby reacted strongly to DTwP, ask your paediatrician whether DTaP would suit the next dose.

My child's whole arm is swollen after the DPT booster. Is that dangerous?

Extensive swelling of the upper arm (or thigh) after a booster is a recognised reaction that looks alarming but usually settles within a few days. Get it checked if the skin is hot and spreading quickly, very painful, oozing, or your child seems unwell.

How can I bring down a fever after the DPT vaccine?

Keep your child lightly dressed, offer plenty of fluids, and give paracetamol in the weight-appropriate dose only if your doctor has advised it. Never give aspirin to a child, and do not give ibuprofen to a baby under 3 months.

Does the DPT reaction get stronger with each dose?

Local swelling and soreness can be more noticeable at the booster doses (16–24 months and 4–6 years) than in early infancy. This is expected and self-limiting, and it is not a reason to skip the booster — completing the schedule keeps protection topped up.

My baby was very unsettled and cried for hours after DPT. What should I do?

Some crying and crankiness is expected. But if the crying is high-pitched and inconsolable for more than 3 hours, or your baby has a fit, a floppy episode or a very high fever, seek medical care and tell your doctor — it may affect how the next dose is planned.

Can DPT be given if my child has a mild cough or cold?

A minor cough or cold without a significant fever is usually not a reason to delay the vaccine. Let the vaccinator know how your child is, and they will decide whether to proceed or postpone.

Your next steps

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Vaccination schedule India

The full IAP-style immunisation chart from birth to the teen years, explained in plain language.

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Find a paediatrician

Worried about a reaction, or due for the next dose? Find a trusted paediatrician near you.

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Related vaccine guides

Pentavalent Vaccine side effectsTdap Vaccine side effectsIPV (Injectable Polio Vaccine) side effectsPCV (Pneumococcal Vaccine) side effects

→ See side effects for all childhood vaccines

Sources

  1. WHO — Vaccine safety and side effects
  2. Indian Academy of Pediatrics (IAP) — Immunization guidelines
  3. CDC — Possible side effects from vaccines
  4. NHS — NHS vaccinations and when to have them
  5. WHO — Diphtheria vaccine position paper
  6. WHO — Tetanus vaccines position paper
  7. NHS — 6-in-1 vaccine side effects

Next review due: 6 January 2027.

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Medical disclaimer

This page is educational information about common vaccine reactions and is not a substitute for medical advice, diagnosis or treatment. Every child is different — always follow the guidance of your paediatrician or vaccination centre. If your child has trouble breathing, swelling of the face or throat, a fast heartbeat, hives all over, dizziness or weakness soon after a vaccine, or seems seriously unwell at any point, seek emergency medical care immediately. When in doubt, always get your child checked — it is never a waste of anyone's time.

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