The 6-in-1 vaccine: what it covers and what to expect
One of the first appointments in your baby's health calendar is a series of injections that offer protection against six serious illnesses in a single jab. It sounds like a lot, but the 6-in-1 is a well-established part of the NHS childhood immunisation programme and a key reason many diseases that once harmed thousands of children each year are now rare in the UK. Here is everything you need to know, based entirely on NHS guidance.
What the 6-in-1 vaccine covers
As the name suggests, one injection delivers immunity against six distinct diseases. Understanding what each one is helps put the importance of the vaccine in context.
- Diphtheria is a bacterial infection that can cause a thick coating in the throat, making it hard to breathe. Before vaccination programmes existed, it was one of the leading causes of childhood death.
- Hepatitis B is a viral infection of the liver. It can be passed from mother to baby around the time of birth, and in some people it becomes a long-term, chronic condition.
- Hib (Haemophilus influenzae type b) is a bacterial infection that can lead to meningitis, pneumonia, and other serious illnesses in young children.
- Polio is a viral disease that can cause paralysis. The oral polio vaccine used in the past has been replaced by an injected version included in the 6-in-1.
- Tetanus is caused by bacteria found in soil and can enter the body through cuts or wounds. It causes painful muscle stiffening and can be life-threatening.
- Whooping cough (pertussis) is a highly contagious respiratory infection. In very young babies, before they have had any vaccinations, it can be extremely serious and sometimes fatal.
Because whooping cough in particular poses the greatest risk to babies in their first weeks of life, the NHS also recommends that pregnant women receive a pertussis booster to pass some protection to their baby before birth. The 6-in-1 course then builds on that early protection once the baby arrives.
When does your baby receive it?
The 6-in-1 is given as a course of injections rather than a single dose. Multiple doses are needed because a baby's developing immune system requires more than one encounter with the vaccine to build a robust, lasting response.
The NHS schedule for the 6-in-1 is:
- 8 weeks old
- 12 weeks old
- 16 weeks old
- 18 months old (for babies born on or after 1 July 2024, a fourth booster dose is now included)
At each of those early appointments your baby will typically receive several other vaccines at the same time, not just the 6-in-1. This is normal and safe. If for any reason a dose is missed, the NHS advises that the vaccine can still be given up to the age of 10, though catching up as soon as possible is preferable.
What to expect on the day
The injection is given into the thigh. Most babies cry briefly at the moment of the jab and then settle. Some parents find it helps to hold their baby skin-to-skin or breastfeed during or just after the injection. Let the nurse or doctor know in advance if your baby has any known allergies, a current high temperature, or any underlying health conditions, particularly anything involving the brain such as epilepsy, as the healthcare professional will need this information before proceeding.
Do not take your baby for the injection if they have a raised temperature on the day. Contact your GP to rearrange the appointment instead.
Common side effects
Reactions after the 6-in-1 are common and generally mild. They are a sign that your baby's immune system is responding to the vaccine, not that something has gone wrong.
- Swelling, redness, or tenderness at the injection site
- A raised temperature
- Seeming tired or sleepier than usual
- Loss of appetite
- Being sick or having looser stools
- Irritability or unsettledness
Children's paracetamol (at the appropriate dose for your baby's age and weight) can help manage a raised temperature or discomfort. Always check the packaging and, if you are unsure about the right dose, ask a pharmacist.
When to call for help
Most post-vaccine reactions settle on their own within 24 to 48 hours. However, there are specific situations where you should contact your GP or call NHS 111 promptly:
- Your baby is under 3 months old and has a temperature of 38°C or higher
- Your baby is 3 to 6 months old and has a temperature of 39°C or higher
- You are worried about your baby for any other reason
In a medical emergency, always call 999 or go to your nearest emergency department.
Who should not receive the vaccine
The 6-in-1 is suitable for the vast majority of babies, but there are a small number of situations where it should not be given or should be delayed:
- Your baby has had a serious allergic reaction (anaphylaxis) to a previous dose of the 6-in-1
- Your baby has a known allergy to any of the vaccine ingredients, including neomycin, polymyxin, formaldehyde, or polysorbate 80
- Your baby has a raised temperature on the day (delay until recovered)
- Your baby has a brain condition such as epilepsy (speak to your doctor before proceeding)
If you have any doubts about whether the vaccine is appropriate for your baby, speak to your GP or health visitor before the appointment rather than simply not attending. Missing doses leaves your child unprotected during the period when they are most vulnerable.
Why completing the course matters
Each dose in the 6-in-1 course builds on the last. After just one or two doses, protection exists but is not yet at its strongest. It is only once all doses in the primary course have been given that your baby has the fullest level of immunity the vaccine can provide. Sticking to the NHS schedule as closely as possible gives your baby the best protection at the earliest opportunity, which matters most for illnesses like whooping cough where even a few extra weeks of unprotected time carries real risk for newborns.
Frequently asked questions
What diseases does the 6-in-1 vaccine protect against?
The 6-in-1 vaccine protects against diphtheria, hepatitis B, Hib (Haemophilus influenzae type b), polio, tetanus, and whooping cough. Six serious illnesses, one injection.
When does my baby get the 6-in-1 vaccine?
On the NHS schedule, babies receive doses at 8 weeks, 12 weeks, and 16 weeks old. A fourth dose is now offered at 18 months for babies born on or after 1 July 2024. If any dose is missed, it can still be given up to age 10.
What side effects are normal after the 6-in-1 vaccine?
Common reactions include pain or swelling at the injection site, a raised temperature, tiredness, loss of appetite, vomiting or diarrhoea, and irritability. These typically resolve within a day or two and can be eased with children's paracetamol at the appropriate dose.
When should I seek urgent help after the 6-in-1 vaccine?
Contact your GP or call NHS 111 if your baby is under 3 months old and develops a temperature of 38°C or higher, or if they are aged 3 to 6 months and reach 39°C or higher. If you are ever in doubt about your baby's condition, do not wait.
Are there any reasons my baby should not have the 6-in-1 vaccine?
The vaccine should not be given if your baby has had a serious allergic reaction to a previous dose or to ingredients such as neomycin, polymyxin, formaldehyde, or polysorbate 80. Vaccination should also be delayed if your baby has a raised temperature on the day. If your baby has a brain condition such as epilepsy, speak to your doctor in advance. For all other concerns, talk to your GP or health visitor rather than skipping the appointment.
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