What to Expect After Baby Vaccines in South Africa: Side Effects by Age

Samantha Pieterse
Oct 2
10 min read

South African mother holding baby after childhood vaccines.

Vaccines are one of the most effective ways to protect babies and children from serious illnesses such as measles, whooping cough, polio, meningitis, and tuberculosis. In South Africa, the vaccination schedule starts right from birth and continues through childhood, giving your child layers of protection at each stage.

It’s completely natural to feel a little anxious after a vaccine visit. Many moms and dads leave the clinic thinking, “Will my baby be okay after those shots?” The reassuring answer is yes, the vast majority of children are absolutely fine. Most side effects are mild, temporary, and a sign that the immune system is doing what it’s meant to do: learning to recognise and fight germs.

Typical side effects include a low-grade fever, fussiness, soreness at the injection site, or changes in sleep and appetite. These usually clear within a day or two. Some vaccines, such as the MMR (measles, mumps, rubella), can cause a rash or mild fever a week later, while the BCG (tuberculosis vaccine) often leaves a small scar; both are expected and normal reactions.

Serious side effects are very rare, but because every child is different, it’s important to know what’s considered “normal” and when it’s time to reach out to a doctor or clinic for extra support.

This guide takes you step-by-step through what to expect after your baby’s vaccines in South Africa, from birth to 12 years old, so that you can feel prepared.

How Do Vaccines Work?

Before we even look at side effects, it’s important to understand what vaccines are doing in your child's body. Think of your baby’s immune system as a tiny but clever security team. Its job is to recognise intruders (germs like viruses and bacteria) and quickly launch a defence before illness takes hold. But the catch is that the team needs training to know what to fight. That’s where vaccines come in.

Vaccines use harmless parts of a germ. This might be a weakened version, a killed version, or just a small piece like a protein. These pieces can’t cause the illness, but they give the immune system the perfect “practice run.”

After vaccination, your baby’s immune system:

Recognises the germ (learns what it looks like).
Builds memory cells (specialised defenders that remember that germ).
Prepares antibodies (protective proteins that can destroy the germ quickly if it shows up again).

This means if your child is exposed later in life, their immune system won’t be caught off guard, and it will react faster and stronger, often stopping the illness before it even starts.

That’s also why some vaccines need boosters. Repeated doses refresh the immune system’s memory, making the protection last for years (or even a lifetime).

💡 Parent tip: A little fever or fussiness after vaccination is a sign the immune system is hard at work building this protection.

Common Vaccine Side Effects in Babies and Children

No matter which vaccine your baby receives, there are a few side effects that come up most often. These are generally mild, short-lived, and nothing to worry about:

Redness, swelling, or a small lump at the injection site. This can last a few days, and sometimes a firm little nodule may remain for weeks. It usually doesn’t bother your baby and fades on its own.
Mild fever (below 38.5°C). A sign the immune system is “switching on.” This typically starts within 24 hours and settles within a day or two.
Fussiness or extra crying. Babies may be clingier, cry more easily, or seem harder to settle for a short while.
Sleepiness or needing extra naps. Many babies sleep more after vaccines. Others might be restless for a night. Both are normal.
Reduced appetite. It’s common for babies to feed a little less for 24 hours. Hydration (milk feeds) is more important than solids at this stage.

💡 Parent tip: Try a cool cloth on the injection site, offer extra cuddles and feeds, and a safe dose of infant paracetamol can help if your baby seems uncomfortable.

👉 Check our South African baby medicine dosage guide here

Common baby vaccine side effects illustrated: fever, sleepiness, reduced appetite, loose stools, crying.

Baby & Child Vaccine Side Effects in South Africa: Quick Reference Table

Vaccines can feel like a big milestone for parents, and it’s normal to wonder what happens afterwards. Most children only experience mild, short-lived reactions, but it helps to know what’s expected at each stage. This table is a quick guide to what to expect after baby shots in South Africa (side effects by age), from the tiny bump left by the BCG at birth to the arm soreness after school boosters.

Age / Vaccine	Common Side Effects (Normal)	When to Call the Doctor
Birth BCG (TB)	Small red bump → blister → scab → scar (weeks). Mild swelling at the site.	Significant swelling, pus, and spreading infection.
Oral Polio (OPV)	Rare. Mild loose stools are possible.	Persistent diarrhoea or vomiting.
6 Weeks Hexavalent (DTaP-IPV-Hib-HepB)	Redness, swelling, fussiness, mild fever, drowsiness.	High fever, seizures, severe swelling.
PCV (Pneumococcal)	Pain at the injection site, sleepiness, and mild fever.	Breathing difficulty, persistent high fever.
Rotavirus (RV)	Mild diarrhoea, irritability.	Severe diarrhoea, blood in stools, dehydration.
10 Weeks Hexavalent, PCV, RV	Same as 6 weeks (mild fever, fussiness, soreness, sleep changes).	Same as above if severe or prolonged.
14 Weeks Hexavalent, PCV	Similar to earlier doses: soreness, low fever, irritability.	High fever, severe allergic reaction.
6 Months Measles/MR	Mild fever, runny nose, mild measles-like rash 7–10 days later.	Rash with breathing problems, prolonged fever.
9 Months PCV booster	Pain at the injection site, mild fever, irritability.	Severe swelling, high fever.
(Private) Meningococcal	Soreness, tiredness, mild fever, headache (older children).	Severe headache, stiff neck, persistent vomiting.
12 Months MMR	Mild rash, fever 1–2 weeks later, swollen glands.	Rash with breathing issues, seizure, prolonged fever.
(Private) Hepatitis A	Soreness at the injection site, tiredness, and mild fever.	Severe allergic reaction, persistent jaundice.
(Private) Chickenpox	Redness at the injection site, mild fever, and a small rash with blisters (mild).	Widespread blistering, high fever.
15 Months (Private) Meningococcal	Similar to 9 months (soreness, fever, headache).	Severe reaction, prolonged vomiting.
18 Months Hexavalent booster	Fussiness, low fever, swelling at the injection site.	Severe swelling, seizures, prolonged fever.
(Private) Hepatitis A booster	Same as first dose: soreness, tiredness, mild fever.	Severe reaction, persistent jaundice.
6 Years Tdap-IPV	Pain at the site, tiredness, headache, and mild fever.	Anaphylaxis, persistent high fever.
Between 9–14 Years HPV	Arm soreness, headache, dizziness, and mild fever.	Severe allergic reaction, fainting, and not improving.
12 Years Tdap booster	Sore arm, mild fever, tiredness.	Severe reaction, breathing problems.
Yearly Flu vaccine	Soreness, mild fever, aches, tiredness for 1–2 days.	Severe allergic reaction, breathing issues.

BCG Vaccine Side Effects in South African Babies

The BCG vaccine, given at birth to protect against tuberculosis (TB), is the one that often causes the most questions for parents. Unlike most other vaccines, the BCG doesn’t just leave a temporary red spot. It goes through a very specific healing process.

Here’s what you can expect after the BCG:

A small red bump usually appears within 2–3 weeks.
This may turn into a blister or ulcer that oozes slightly before forming a scab.
Over the next few weeks to months, it heals and leaves a small, flat scar.
This scar is completely normal and shows that the vaccine worked.

When to call Mums & Bums

If the swelling is very large (bigger than a R5 coin),
If the site is oozing pus heavily, or
If it doesn’t heal after several months.

💡 Many parents worry when the BCG site looks “angry” or slow to heal, but this is part of the normal immune response.

👉 For a detailed step-by-step guide (with pictures), read our full blog: BCG Vaccine in South Africa: Side Effects, Healing & Scar Guide

BCG vaccine scar progression in babies, from injection bump to healed scar (South Africa). — *The BCG vaccine scar is a normal part of healing and shows your baby is protected against TB.*

Specific Concerns After Baby Vaccines: Fever, Vomiting & Rash

Even when parents know most vaccine side effects are mild, there are a few specific symptoms that can feel worrying in the moment. Here’s what you need to know about the ones we get asked about most often:

Fever After Vaccines

A mild fever (below 38.5°C) within the first 24 hours is very common and shows the immune system is responding.
Some vaccines, like the MMR, can cause a delayed fever about 7–10 days later. This often catches parents off guard, but it is completely normal.
High fever (above 39.5°C), a fever lasting more than 3 days, or fever with other worrying symptoms (such as lethargy, seizures, or refusal to feed) should be checked by a doctor.

👉 Read our full guide on baby fevers here

Vomiting After Baby Vaccines

Spit-up or even one-off vomiting can happen after crying hard or from the rotavirus oral vaccine.
Mild diarrhoea for a day or two is also fairly common after rotavirus.
Persistent vomiting or vomiting with signs of dehydration (dry mouth, sunken soft spot, fewer wet nappies) needs medical review.
Rarely, the rotavirus vaccine can be linked to intussusception (bowel folding in on itself). This is extremely uncommon, but seek urgent care if your baby has severe abdominal pain, pulls their legs up repeatedly, or passes bloody stools.

👉 Read our guide on valoid for babies who are vomiting here

👉 Learn about dehydration in babies and children

Rash After Vaccines

Mild rashes are most often linked to the MMR vaccine and can appear 7–10 days later. They’re not contagious and usually fade on their own.
Some babies also get a small rash at the injection site, which may look like tiny red spots or mild swelling.
What’s normal: Small, localised rash or mild body rash without other symptoms.
What’s not normal: A rapidly spreading rash with high fever, swelling of the face/lips, or breathing difficulties. These need urgent medical attention.

What These Symptoms Mean After Baby Vaccines

Most babies handle vaccines with only mild fussiness, a bit of fever, or a small rash that clears quickly. These are signs that the body is learning and building protection. The important thing is this: if the symptoms are mild and your baby is otherwise feeding, sleeping, and looking well, there’s usually no cause for concern. But if something feels off or your gut tells you it’s more than just a side effect, it’s always better to give us a call.

Is It True You Should Wash Your Hands and Not Kiss Your Baby After the Rotavirus Vaccine?

The rotavirus vaccine is given orally (a few drops in your baby’s mouth) to protect against severe diarrhoea and dehydration. After the dose, the weakened virus can pass through your baby’s stools for up to about 10 days. This is completely normal, but it does mean parents need to take a few extra hygiene precautions.

Here’s what to know:

Handwashing is essential. Always wash your hands thoroughly with soap and water after changing nappies. Alcohol hand sanitiser doesn’t kill rotavirus as effectively.
Nappy disposal is important. If you’re using disposable nappies, seal them tightly before throwing them away. For cloth nappies, wash them separately in hot water.
Kissing your baby is safe. The vaccine doesn’t spread through saliva, so cuddling and kissing your baby is completely fine.
Be mindful of vulnerable people. For the first 10 days after vaccination, try to limit close contact between your baby’s dirty nappies and people with weak immune systems (like those on chemotherapy or living with HIV), very frail elderly people, or other young babies who haven’t yet had their own rotavirus vaccine.

💡 Bottom line: Kisses and cuddles are safe, but strict handwashing and extra care around sick or elderly relatives help keep everyone protected.

Parent washing hands after baby’s rotavirus vaccine, South Africa. — *After the rotavirus vaccine, wash your hands carefully during nappy changes to prevent spreading the virus.*

Baby Vaccine Side Effects: When to Contact Our Clinic

Most babies bounce back quickly after their vaccines with only mild fussiness, a small fever, or extra naps. But every child is different, and sometimes side effects can be stronger. It’s always okay to reach out if you’re worried. Call your clinic or doctor straight away if you notice any of these:

Fever above 39.5°C or lasting more than 3 days
A low-grade fever is expected, but a high or persistent fever can be a sign of something else that needs checking.
Nonstop crying for more than 3 hours
Babies are often fussy after vaccines, but if your child is inconsolable, screams sharply, or can’t be settled, it’s worth getting medical advice.
Seizure or fit (rare, usually linked to high fever)
Febrile seizures can be frightening, but are usually not harmful. Still, they should always be assessed by a healthcare professional.
Signs of a severe allergic reaction
These include swelling of the face, lips, or tongue, difficulty breathing, widespread hives, or sudden limpness. Most allergic reactions happen within minutes of the injection, which is why clinics ask you to wait for observation after vaccines, but if it happens later, treat it as an emergency.
Anything that doesn’t feel right
Trust your instincts. If your baby seems unusually floppy, very hard to wake, refuses all feeds, or just “doesn’t look right” to you, it’s safest to have them checked.

💡 Parent reassurance: These serious reactions are extremely rare. The vast majority of babies recover from vaccines with only mild, short-lived side effects. But knowing when to call for help gives you peace of mind, and we never mind hearing from you if you’re unsure .

Red flag vaccine side effects in babies: high fever, nonstop crying, allergic reaction, seizures.

FAQs About Baby Vaccine Side Effects in South Africa

What are the normal side effects after baby vaccines?

Mild fever, fussiness, extra sleepiness, and soreness at the injection site are the most common side effects. These usually last 1–2 days.

Can babies get a fever after vaccines?

Yes, a mild fever under 38.5°C is common and usually short-lived. Call your doctor if the fever is higher than that or lasts longer than 3 days.

Is vomiting normal after baby vaccines?

Occasional spit-up or one-off vomiting after crying is common. Persistent vomiting or signs of dehydration (dry mouth, fewer wet nappies) should be checked by a healthcare provider.

What are the BCG (TB vaccine) side effects in babies?

A red bump appears at the injection site within 2–3 weeks, which may blister and scab before leaving a small scar. This is normal. If the swelling is very large or oozing pus, contact your clinic.

Do vaccine side effects differ by age?

Yes. At 6 weeks and 3–4 months, fussiness and mild fever are common. At 9–12 months, the MMR vaccine can cause a mild rash and fever 1–2 weeks later.

How long do baby vaccine side effects last?

Most settle within 24 to 48 hours. The BCG vaccine bump can take weeks to heal fully.

When should I worry about vaccine side effects?

Seek medical care if your baby has a fever above 39.5°C, nonstop crying for more than 3 hours, seizures, or an allergic reaction (difficulty breathing, swelling of face or lips, widespread rash).

Why These Side Effects Are Usually Nothing to Worry About

Most side effects from baby vaccines are short-lived and show your little one’s immune system is getting stronger. A bit of fussiness or a low-grade fever is far less scary than the illnesses these vaccines prevent.