Fever
What helps
- Dress your child in light, comfortable layers
- Offer plenty of feeds or fluids
- Check the temperature rather than guessing
Better to avoid
- Bundling a warm child in extra blankets
- Ice-cold sponging — lukewarm is gentler
💉 Vaccination · Parent's guide
Vaccine Side Effects in Babies & Children
A little fever, a sore leg, an unsettled night — mild reactions after vaccines are common, expected, and usually a sign the immune system is doing its job. These guides explain what's normal after each childhood vaccine, how to keep your little one comfortable at home, and exactly which warning signs mean it's time to call a doctor.
- ✓ Fact-checked against WHO, IAP, CDC & NHS
- ✓ Based on India's IAP/NIS schedule
- ✓ Emergency signs on every guide
- ✓ Updated July 2026
17
Vaccine guides
Birth–teen
Full schedule covered
IAP
India-first guidance
🚨
Emergency signs included
17 vaccine guides · India's IAP/NIS schedule · fact-checked against WHO, IAP, CDC & NHS guidance.
Birth Vaccines
At birth · 3 vaccinesBCG, OPV and Hepatitis B — the first vaccines, usually given before you leave the hospital.
At birth
BCG Vaccine
Sore spot · slow-healing scar
🟢 Usually mild⏱ Heals over 2–3 months
Learn moreBirth + 6–14 wks
Hepatitis B Vaccine
Sore thigh · brief low fever
🟢 Usually mild⏱ 1–2 days
Learn moreBirth + doses
Oral Polio Vaccine (OPV)
Usually none · brief fussiness
🟢 Usually mild⏱ Hours, if anything
Learn more6–14 Week Vaccines
6–14 weeks · 5 vaccinesThe primary series at 6, 10 and 14 weeks — pentavalent, DPT, polio, rotavirus and PCV doses.
6, 10 & 14 wks
Pentavalent Vaccine
Fever · sore thigh · fussiness
🟢 Usually mild⏱ 1–2 days
Learn more6 wks – 6 yrs
DPT Vaccine
Fever · swollen thigh/arm
🟢 Usually mild⏱ 1–3 days
Learn more6 & 14 wks
IPV (Injectable Polio Vaccine)
Brief soreness · small red spot
🟢 Usually mild⏱ 1–2 days
Learn more6 & 14 wks + booster
PCV (Pneumococcal Vaccine)
Sore thigh · fever · sleepiness
🟢 Usually mild⏱ 1–2 days
Learn more6, 10 & 14 wks
Rotavirus Vaccine
Mild fussiness · loose stools
🟢 Usually mild⏱ About a day
Learn more6–12 Month Vaccines
6–12 months · 4 vaccinesInfluenza, typhoid, MMR and Japanese encephalitis doses given in the second half of the first year.
9 mo, 15 mo, 4–6 yrs
MMR Vaccine
Delayed fever · faint rash
🟢 Usually mild⏱ 1–3 days (starts day 5–12)
Learn more6 mo+, yearly
Flu (Influenza) Vaccine
Sore arm · mild fever · aches
🟢 Usually mild⏱ 1–2 days
Learn more9 & 16–18 mo
Japanese Encephalitis Vaccine
Sore site · low fever
🟢 Usually mild⏱ 1–2 days
Learn more6–9 months
Typhoid Vaccine (TCV)
Sore arm · low fever · tiredness
🟢 Usually mild⏱ 1–3 days
Learn moreToddler Vaccines
12–24 months · 2 vaccinesHepatitis A, chickenpox (varicella) and booster doses given between 12 months and 2 years.
School-Age & Preteen Vaccines
4–16 years · 3 vaccinesBoosters and preteen vaccines — Tdap, HPV and COVID-19 doses for older children and teens.
The typical first 48 hours
For most injected baby vaccines, reactions follow a familiar arc — here is the pattern most parents see. Every child is different, and some vaccines have their own timeline.
Immediately
Brief crying at the injection; centres ask you to wait 15–30 minutes to watch for rare immediate reactions.
First 6 hours
The site may start to feel tender. Some babies get fussy, sleepy or feed a little less.
6–24 hours
This is when a mild fever most often appears. An unsettled night is common — comfort and feeds help.
24–48 hours
Fever and fussiness usually fade. Site soreness or a small firm lump can linger a little longer.
By day 2–3
Most babies are fully back to themselves. A painless lump at the site can take 1–2 weeks to vanish.
Recovered
Anything still worsening instead of settling — or any red-flag sign at any point — deserves a doctor's check.
The big exceptions: live vaccines react late. MMR and chickenpox (varicella) can cause a mild fever or faint rash 5–12 days after the shot, and the BCG sore evolves over weeks. Each vaccine guide below covers its own timeline.
How to keep your baby comfortable
Simple comfort measures cover almost every normal vaccine reaction. Each vaccine guide adds specifics, but these six basics rarely change:
Fluids & feeds
What helps
- Breastfeed or offer milk on demand — it soothes and hydrates
- Small, frequent feeds if appetite dips
Better to avoid
- Worrying over one smaller feed — watch wet nappies instead
- Forcing solids on an off-colour toddler
Rest & comfort
What helps
- Extra cuddles, skin-to-skin and a calm routine
- Let your child nap more than usual if they want to
Better to avoid
- A packed, stimulating day right after vaccines
- Waking a settled baby to check on them constantly
The sore spot
What helps
- A cool, clean, damp cloth held gently on the site
- Loose sleeves or nappies that don't rub the area
- Moving the leg or arm normally — it eases stiffness
Better to avoid
- Massaging, squeezing or applying pressure to the site
- Creams, ointments or home remedies unless your doctor advises
Medicines
What helps
- Paracetamol for a genuinely feverish, uncomfortable child — in the dose your doctor has advised for their weight
- Calling your doctor first for any baby under 3 months
Better to avoid
- Routine 'just in case' doses before symptoms appear
- Aspirin — never for children
Watching & recording
What helps
- Note the vaccine date — delayed reactions (MMR, chickenpox) appear days later
- Record the dose on your vaccination card or tracker
Better to avoid
- Comparing your child hour-by-hour with other babies
- Sitting on a worry — a quick call to your doctor is always fine
🖨️ After-Vaccination Care Checklist
A one-page printable to stick on the fridge — temperature log, medicine notes, feeding, the next due dose and your doctor's number.
When to seek urgent help — for any vaccine
Serious vaccine reactions are rare, but they need emergency care. Go to the nearest hospital or call your doctor immediately if your child has any of these after a vaccine:
- Difficulty breathing, noisy breathing, or swelling of the face, lips or tongue
- Widespread hives or sudden paleness, floppiness or unresponsiveness
- A fever of 40°C (104°F) or higher, or any fever in a baby under 3 months
- A seizure (fit), or unusual drowsiness where your child is hard to wake
- Inconsolable crying for more than 3 hours
- Anything that makes you feel your child is seriously unwell — trust your instinct
Call your doctor immediately — or go straight to the nearest emergency department.
🩺 Find a paediatricianSevere allergic reactions usually start within minutes of the injection — which is why vaccination centres ask you to wait 15–30 minutes before leaving.
All vaccines at a glance
A quick comparison of what each vaccine typically causes. Tap any vaccine for its full guide — including home care and every warning sign.
| Vaccine | Fever | Rash | Site swelling | Usually settles | See a doctor for |
|---|---|---|---|---|---|
| BCG | Uncommon | No | Sore → boil → scar | 2–3 months (scar forms) | Large abscess, big armpit lump |
| Hep B | Occasional, first 24 h | No | Small red spot common | 1–2 days | Any fever under 3 months old |
| OPV | Rare | No | None (oral drops) | Usually none | Allergic reaction, limb weakness |
| DPT | Common (DTwP more) | No | Common; larger after boosters | 1–3 days | Fever ≥40°C, seizure, floppiness |
| IPV | Occasional, low-grade | No | Small red spot possible | 1–2 days | Allergic reaction, high fever |
| PCV | Fairly common | No | Common at site | 1–2 days | Fever ≥40°C, inconsolable crying |
| Pentavalent | Common, first 24–48 h | No | Common, can look dramatic | 1–2 days | Fever ≥40°C, seizure, 3 h+ crying |
| Rotavirus | Occasional, mild | No | None (oral drops) | About a day | Tummy-pain spasms, blood in stool |
| Flu | Common, mild | No | Common at site | 1–2 days | Breathing trouble, high fever |
| JE | Common, low-grade | No | Common at site | 1–2 days | Confusion, stiff neck, fever |
| MMR | Delayed: day 5–12 | Faint, day 5–12 | Mild soreness | 1–3 days once it starts | Seizure, high fever |
| Typhoid | Occasional, low-grade | No | Common at site | 1–3 days | High fever, child seems unwell |
| Varicella | Occasional, can be delayed | Few spots, day 5–26 | Mild at site | 1–2 days | Widespread rash, high fever |
| Hep A | Occasional, low-grade | No | Common at site | 1–2 days | High fever, child seems unwell |
| COVID-19 | Common, brief | No | Common at site | 1–2 days | Chest pain, breathlessness |
| HPV | Occasional, mild | No | Very common at site | 1–2 days | Fainting with injury, allergy |
| Tdap | Occasional, mild | No | Common; can be large | 1–3 days | Whole-arm swelling, high fever |
Typical patterns only — every child is different, and this table is not a diagnostic tool. Severe allergic reactions (breathing difficulty, facial swelling) after any vaccine always need emergency care.
Your next steps
Track your baby's vaccines
Enter your baby's birth date to get a personalised vaccine timeline with reminders, so no dose slips.
Open Vaccination TrackerVaccination schedule India
The full IAP-style immunisation chart from birth to the teen years, explained in plain language.
See the full scheduleFind a paediatrician
Worried about a reaction, or due for the next dose? Find a trusted paediatrician near you.
Find a pediatricianFrequently asked questions
Are vaccine side effects a sign that something is wrong?
Usually the opposite — mild fever, fussiness or a sore injection spot show the immune system is responding and building protection. Most reactions are mild and settle within a day or two. Each vaccine guide on this page explains what's typical for that specific vaccine.
How long do vaccine side effects usually last in babies?
Most common reactions — soreness, low-grade fever, sleepiness, fussiness — settle within 24 to 48 hours. A few vaccines have their own timelines: the BCG sore evolves over weeks, and live vaccines like MMR and chickenpox can cause a mild delayed fever or rash 5–12 days later.
Can I give paracetamol after vaccination?
Paracetamol can help a genuinely feverish or uncomfortable child, in the dose your paediatrician has advised for your child's weight. It isn't recommended routinely 'just in case' before symptoms appear. For babies under 3 months, always check with your doctor first — and never give aspirin to children.
When should I take my child to a doctor after a vaccine?
Seek urgent care for trouble breathing, swelling of the face or lips, widespread hives, a fever of 40°C or higher, a seizure, unusual floppiness or unresponsiveness, or inconsolable crying for more than three hours. For anything milder that isn't settling — or any change that worries you — call your paediatrician. Trust your instinct.
Should I delay the next vaccine if my baby had side effects?
Common reactions like fever or a sore leg are not a reason to skip or delay future doses — but always tell your paediatrician what happened. Only a small number of specific, serious reactions change the plan, and your doctor will advise if that applies.
Continue on ParentVibes
This library is educational information, not medical advice, and is not a substitute for consulting your paediatrician. Every child is different — always follow your own doctor's guidance. Read our Medical Disclaimer.
Never miss another vaccine.
ParentVibes keeps the whole journey in one calm place — what's due, what to expect after, and what happened when.
- Personalised vaccine reminders before every due date
- Your baby's full vaccination timeline from their birth date
- Side-effect guidance linked to each dose
- Records and certificates in one private place
Create free accountOpen Vaccination Tracker
Free forever · private & secure · built for Indian families