The BCG vaccine is designed to protect your child against catching a disease called tuberculosis (TB). TB is a bacterial infection that mainly affects the lungs, but the more severe form can also cause meningitis (swelling of the brain) in young children, and abscesses can form in the spine or other key structures. There are over 5,000 new cases a year, but it’s more common in South East Asia, sub-Saharan Africa and other parts of the world. TB is infectious and can spread by coming into contact with the infected droplets of another person – by them coughing, sneezing or speaking while they have the so-called “active” form of the infection. The bacteria needs a bit of time and exposure to pass itself on, so it’s usually transmitted through very close and prolonged contact, like in the workplace, or living with someone infected. The vaccine contains a weakened form of the bacteria that cannot cause the disease but will protect your baby if they ever come into contact with the disease. But it’s not offered to every baby in the UK.
TB in young babies can affect the lungs, causing a persistent cough lasting more than 2 weeks but it can cause other symptoms like fatigue, fever, difficulty gaining weight or even weight loss. If TB does occur, there is a medical treatment regime that can cure the disease over several months.
In the UK, the BCG vaccine is offered to babies who are deemed to be at higher risk of catching TB. This can be if they have a family member who comes from a country with high rates of TB, if they live in an area with high rates or you know someone who has current or past TB infection. The vaccination is usually given just after birth or within the first month and it is injected into the upper outer arm.
You're likely to see a raised blister at the injection site, along with soreness and redness. Between 2 and 6 weeks later, a spot will appear that should slowly heal but may leave a small scar. If there is any sign of infection, you should contact your doctor for review.
You should postpone your appointment if your baby is unwell with a fever at the time. If your child has a weakened system due to severe medical illness or immune-suppressing medication, you should speak with your child's specialist, as the weakened bacteria in the vaccine could cause them a serious infection. But your specialist may suggest that the risk of severe illness if they caught TB would be worse. As with any vaccine, it's up to you whether you take up the offer for your child to receive the vaccine. You may have further questions to ask of your doctor or practice nurse before coming to a decision. However, if your child or anyone else including adults has TB, it's a condition that, by law, requires the full dose of antibiotic treatment. It's known as a notifiable disease that doctors have to tell the UK health authority about.