Quick Answer: Most post-vaccination symptoms are mild and usually settle on their own — they often show that your baby’s immune system is responding. In babies 3 months and older, a mild low-grade fever (up to about 100.4–101°F / 38–38.3°C) that settles in 1–2 days, fussiness, and soreness at the injection site are common and usually resolve within 1-3 days. In any baby UNDER 3 months, a temperature of 100.4°F (38°C) or higher needs same-day medical review regardless of recent vaccination — do not assume it is just the vaccine. These temporary discomforts are a small price for protecting your baby from serious diseases. You’re doing a great job, mummy-papa!
Why Do Reactions Happen After Vaccination?
Vaccines work by teaching your baby’s immune system to recognize and fight diseases. When the immune system “wakes up” to learn, it sometimes causes mild, temporary side effects.
Think of it this way: Just like how your body might feel tired after a workout, your baby’s immune system is “working out” after a vaccine!
Reassurance: These reactions are signs that the vaccine is working and your baby’s body is building protection.
Common Mild Symptoms (Normal - Don’t Worry!)
These symptoms are expected and usually last 1-3 days:
At the Injection Site (Teeka Ki Jagah Par)
| Symptom | What You’ll See | Duration |
|---|---|---|
| Redness | Pink or red patch around injection | 1-3 days |
| Swelling | Slight puffiness | 1-3 days |
| Tenderness | Baby cries when touched there | 1-2 days |
| Small lump | Painless, hard nodule | May last weeks - this is okay! |
General Symptoms
| Symptom | What’s Normal | Duration |
|---|---|---|
| Low fever (babies ≥3 months) | Up to about 100.4–101°F (38–38.3°C) | 1-2 days |
| Fussiness | More crying/clingy than usual | 1-2 days |
| Sleepiness | Sleeping more than usual | 24-48 hours |
| Less appetite | Not feeding as much | 1-2 days |
| Mild rash | After MMR vaccine (7-10 days later) | Fades on its own |
Note on timing: Most reactions occur within 24-48 hours of vaccination. MMR vaccine may cause mild rash 7-10 days later.
How to Comfort Your Baby After Vaccination
For Local Soreness (Injection Site Pain)
What helps:
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Apply clean, cool, damp cloth gently on the sore area
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Avoid pressing or massaging the area
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Allow gentle movement of the limb
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Dress baby in loose, soft clothing
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Don’t apply any creams unless doctor advises What to avoid:
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Don’t apply ice directly
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Don’t massage vigorously
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Don’t apply home remedies (turmeric paste, etc.) on injection site
For Mild Fever and Discomfort
⚠️ In a baby under 3 months, ANY fever of 100.4°F (38°C) or higher is a medical emergency — see a doctor the same day, even at night. Do not give paracetamol and wait. This applies even after a vaccine.
Step 1: Check with your pediatrician about paracetamol
- Don’t give any medicine without doctor’s advice
- If advised, use infant paracetamol syrup (Crocin, Calpol, etc.)
- Follow dosage based on baby’s WEIGHT, not age
- Use the measuring cup provided - not household spoons!
Paracetamol is dosed by your baby’s weight, not age: 15 mg/kg per dose, no more often than every 4–6 hours, maximum 4 doses (60 mg/kg) in 24 hours. Syrup strengths differ — Calpol/Crocin come as 120 mg/5 ml and 250 mg/5 ml, so always check the bottle. Do not give to a baby under 3 months without a doctor seeing them first. Confirm the exact mL with your pediatrician. Step 2: Keep baby hydrated
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Offer more breastfeeds (maa ka doodh is the best medicine!)
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Formula-fed babies: offer small, frequent feeds
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Older babies: offer water sips Step 3: Dress lightly
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Light cotton clothes
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Don’t overdress even with fever
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Keep room comfortably cool Step 4: Extra love and comfort
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More cuddles and skin-to-skin contact
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Gentle rocking or swaddling
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Quiet, calm environment
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Nursing on demand
For Fussy Baby
- Offer the breast or pacifier
- Gentle rocking in your arms
- Soft singing or white noise
- Skin-to-skin contact (kangaroo care)
- Be patient - this phase passes quickly!
Which Vaccines Cause Which Reactions?
| Vaccine | Common Reactions | Timing |
|---|---|---|
| DTaP/DPT | Fever, fussiness, soreness | 24-48 hours |
| Polio (IPV) | Usually none, mild soreness | 24 hours |
| Hepatitis B | Mild soreness | 24-48 hours |
| BCG | Small lump that may ulcerate - usually expected | 2-6 weeks |
| MMR | Mild fever, rash | 7-10 days later |
| Rotavirus (oral) | Mild diarrhea, fussiness | 1-2 days |
| Pneumococcal (PCV) | Fever, irritability | 24-48 hours |
BCG special note: The BCG vaccine (given at birth) causes a small lump that may form a pustule and even a small scar over 2–6 weeks. This is usually expected. BUT if the swelling is larger than ~1 cm, spreads, the armpit gland swells, or there is increasing redness or discharge, show your pediatrician — this can be a BCG abscess or gland infection that needs review.
When to Call the Doctor (Warning Signs)
Seek IMMEDIATE Medical Care If:
These symptoms are rare but need urgent attention:
High fever:
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ANY fever of 100.4°F (38°C) or higher in a baby under 3 months — go now, do not wait, do not give paracetamol first
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Temperature above 102°F (39°C)
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Fever lasting more than 3 days Severe reactions:
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Inconsolable crying for 3+ hours
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Seizures or convulsions (fits)
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Extreme lethargy - difficult to wake up
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Limp, unresponsive Signs of allergic reaction (anaphylaxis - very rare):
This happens within minutes to 2 hours of vaccination:
🚨 Call 112 (national emergency) or 108 (ambulance), or go straight to the nearest hospital, if you see: difficulty or noisy breathing; swelling of the face, lips or tongue; widespread hives with vomiting; pale, grey or blue skin; floppiness or unresponsiveness; or a seizure. These can be a severe allergic reaction (anaphylaxis). If an adrenaline auto-injector has been prescribed, use it first, then go. Do not wait for a clinic appointment.
This is why your clinic will usually ask you to stay and watch your baby for about 15 minutes after the shot — so that a rare immediate reaction can be treated on the spot.
After Rotavirus vaccine, watch for:
- Severe vomiting
- Bloody stools
- Severe abdominal pain with crying (Could indicate rare bowel issue - needs immediate attention)
Schedule a Doctor Visit If:
- Symptoms persist beyond 3 days
- In a baby 3 months or older, fever is between 101-102°F and you’re concerned (in a baby under 3 months, any fever of 100.4°F/38°C or higher = go the same day, see above)
- Baby refuses all feeds for extended period
- Anything that “just doesn’t feel right” Trust your instincts! If something seems wrong, it’s always okay to call your doctor.
Vaccine-by-Vaccine Schedule (Indian Context)
Here’s roughly when to expect vaccines in India, based on the IAP (Indian Academy of Pediatrics) schedule. At 6, 10 and 14 weeks, Hib is usually included — most clinics give DTaP + IPV + Hib + Hep B as a single combined (pentavalent) injection, plus PCV and oral Rotavirus:
| Age | Vaccines | Expected Reactions |
|---|---|---|
| Birth | BCG, OPV, Hep B | BCG lump usually expected |
| 6 weeks | DTaP, IPV, Hib, Hep B, Rota, PCV | Fever, fussiness common |
| 10 weeks | DTaP, IPV, Hib, Rota, PCV | Fever, fussiness common |
| 14 weeks | DTaP, IPV, Hib, Rota, PCV | Fever, fussiness common |
| 6 months | Hep B-3 (± OPV per your clinic) | Usually mild |
| 9 months | MMR (IAP currently recommends MMR-1 at 9 months) | Possible rash 7-10 days later |
| 12 months | Hep A, Varicella | Mild fever |
Schedules vary — follow the exact schedule and brands your pediatrician gives you. Sources: IAP Advisory Committee on Vaccines (ACVIP) immunization schedule.
Frequently Asked Questions
Q: Should I give paracetamol before vaccination to prevent fever?
A: Most pediatricians don’t recommend giving paracetamol BEFORE vaccination. Some research suggests it may slightly reduce the immune response. Give only if fever develops and doctor advises.
Q: Can I breastfeed right after vaccination?
A: Yes! Breastfeeding during or immediately after vaccination actually helps calm baby and may reduce pain. Maa ka doodh is the best comfort!
Q: My baby slept a lot after the vaccine. Is this normal?
A: Yes, increased sleepiness for 24-48 hours is very common. The immune system is working hard! Just ensure baby wakes for feeds.
Q: The injection site has a hard lump that won’t go away. Is this concerning?
A: Small, painless lumps at injection site can last for weeks or even months. This is normal and will eventually disappear. Only worry if it’s growing, painful, or red.
Q: Can I give baby a bath after vaccination?
A: Yes, you can bathe baby normally. Avoid vigorously rubbing the injection site.
Q: My older child has a cold. Should I delay baby’s vaccination?
A: Mild illnesses like a cold don’t usually require delaying vaccines. However, check with your pediatrician who can assess if your baby is well enough.
Q: The BCG site is forming a pus-filled boil. Is this an infection?
A: This is usually expected for BCG. The vaccine causes a small lesion that may ulcerate and form a scar over a few weeks. Don’t apply any creams or try to pop it. However, if the swelling grows larger than ~1 cm, spreads, the armpit gland swells, or there is increasing redness or discharge, show your pediatrician — that can be a BCG abscess or gland infection rather than the usual reaction.
Key Takeaways
- Mild reactions are normal - Show the vaccine is working
- Most symptoms last 1-3 days - Be patient
- Comfort is key - Cuddles, breastfeeding, and rest help
- Know the warning signs - High fever, seizures, difficulty breathing need immediate care
- When in doubt, call your doctor - Trust your instincts
- Vaccines save lives - These temporary discomforts protect from serious diseases
This article was reviewed by pediatricians at Babynama. Last updated: January 2026
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This article is general information for Indian parents, not a substitute for examination by your pediatrician. In an emergency, call 112 or 108.