BCG vaccine

Overview

The BCG vaccine (Bacillus Calmette-Guérin) helps protect a baby against tuberculosis (TB).

What’s TB?

TB is a serious infectious disease. TB can progress rapidly, particularly in young children and infants, and can lead to TB meningitis (swelling of the lining of the brain) in babies.

In young people and adults it usually affects the lungs, but can also affect the:

  • lymph glands
  • brain
  • joints
  • kidneys
  • bones

Most people in the UK recover fully after treatment, but this usually takes several months.

How common is TB?

TB isn’t a common disease. In Scotland, fewer than 300 new cases of TB are diagnosed every year.

Cases of TB can be found all over the world, with some countries experiencing high rates of TB.

The risk of getting TB is higher for people who have lived or worked in countries with high rates of TB.

An up-to-date list of countries with high rates of TB is available on the GOV.UK website.

More about tuberculosis

Who is offered the vaccine?

The BCG vaccine is offered to babies who are more likely to come into contact with someone with TB. This is because they either lived in an area with high rates of TB, or their parents or grandparents came from a country with high rates of TB.

A baby is eligible for the BCG vaccine if:

  • they have a parent or grandparent who was born in a country with a high rate of TB
  • you and the baby live or plan to live for more than three months in an area with a high rate of TB in the near future
  • anyone in your house, or anyone else who is likely to have prolonged contact with the baby, has TB, has had it in the past, or was born in a country with a high rate of TB

If you are unsure if a baby meets these criteria, please speak to a health professional.

An up-to-date list of countries with high rates of TB is available on the GOV.UK website.

When will a baby be immunised?

A baby is likely to be identified as eligible and offered the vaccine soon after birth. However, the vaccine can be given at any time.

The vaccine is given while you hold the baby comfortably on your knee. The health professional will inject the vaccine just under the skin of the upper part of the baby’s left arm.

Find out how to contact your local NHS immunisation team regarding your baby’s vaccination appointment

If you’re unsure about anything, or have any questions about the BCG vaccine, phone:

The vaccine

The BCG vaccine contains a weakened form of the bacteria (germs) that cause TB. The vaccine doesn’t actually cause TB, but it helps a baby develop protection (immunity) against the disease in case they ever come into contact with it.

The vaccine only needs to be give once.

What vaccine is used?

The BCG vaccine AJV is routinely used in Scotland.

How do we know the vaccine is safe?

All medicines (including vaccines) are tested for safety and effectiveness by the Medicines and Healthcare Products Regulatory Agency (MHRA). The vaccine meets the high safety standards required for it to be used in the UK and other European countries. The vaccine has been given to millions of people worldwide.

Once they’re in use, the safety of vaccines continues to be monitored by the MHRA.

Are there any reasons why a baby shouldn’t have the BCG vaccination?

The BCG vaccine should be delayed if the baby has a high fever.

The BCG vaccine may also be delayed in babies born to mothers who received treatment during pregnancy or breastfeeding that may have weakened their immune system, such as anti-TNF therapy. It may also be delayed for babies born to mothers who are HIV positive. Please consult your health professional for further advice if this applies to the baby you are bringing.

If the baby is less than two years of age and lives in a household where there is a suspected or confirmed case of active TB, the baby must be tested for TB before they receive the vaccine. They will be able to be vaccinated if they are not already infected.

Other reasons the BCG vaccine should not be given include if the baby:

  • has a weak immune system due to any disease or treatment
  • is HIV positive
  • has had a confirmed severe allergic reaction (anaphylactic reaction) to an ingredient of the vaccine
  • has or might have severe combined immunodeficiency (SCID), including babies waiting for a screening result

The BCG vaccine should also not be given if the baby is suffering from a generalised septic skin condition. Babies with eczema, however, can be given the vaccine in an area without broken skin.

After the vaccine

After having the vaccine there may be side effects, but these are usually mild.

Vaccines protect a baby against the risk of very serious infections and should not be delayed.

Side effects

Immediately after the vaccine is given, a raised blister will appear. This shows that the vaccine’s been given properly.

Within 2 to 6 weeks, a small spot will appear. This may be quite sore for a few days, but it’ll gradually heal and may leave a small scar.

Occasionally, the baby may develop a small sore where the vaccine was injected. If this is leaking and needs to be covered, use a dry dressing – never a waterproof plaster or creams – until a scab forms. It’s better to leave the sore uncovered if possible and it’s fine to leave it uncovered when bathing. This sore may take several months to heal completely.

Call your GP if:

  • you think the sore has become infected
  • you are worried about the baby’s health

Fever can be expected after any vaccination. Fevers are usually mild, so you only need to give a dose of infant paracetamol if the child isn’t comfortable or is unwell. Read the instructions on the bottle very carefully.

Ibuprofen can also be used to treat a fever and other post-vaccination reactions. Read the instructions on the product packing very carefully. Giving ibuprofen at the time of vaccination to prevent a fever is not effective.

Remember, never give medicines that contain aspirin to children under 16.

In infants who do develop a fever after vaccination, the fever tends to peak around 6 hours after vaccination and is nearly always gone completely within 2 days.

Read more about treating a fever in children

Call 999 immediately if:

  • the child is having a fit

If you think the child might be seriously ill, trust your instincts and seek urgent medical advice.

Phone your GP immediately if the child:

  • has a temperature of 39°C or above
  • still has a fever 48 hours after vaccination
  • you are concerned about the child’s health

If your GP practice is closed, phone the 111 service.

The diseases vaccines protect against are very serious and therefore vaccination should not be delayed because of concerns about post-vaccination fever.

Vaccine Safety Net Member

Public Health Scotland is a proud member of the Vaccine Safety Net and partners with NHS inform to provide reliable information on vaccine safety.

The Vaccine Safety Net is a global network of websites, evaluated by the World Health Organization, that provides reliable information on vaccine safety.

More about the Vaccine Safety Net

Further information and other languages/formats

More information vaccinations can be found in these leaflets, available in multiple formats and languages.

If you need a leaflet in a different language or format, please contact phs.otherformats@phs.scot

Last updated:
19 December 2023

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