Our study is based on the idea that BCG vaccination will promote the development of an immune system that is better at fighting infection and less prone to allergy.
Each of the 1,400 babies enrolled in the BAIR study will be randomly allocated, shortly after birth, into one of two groups. One group will be be given the BCG vaccine and the other will not. Regardless of which group each MIS BAIR baby is allocated to, we will follow them until they are about one year old looking for the causes and signs of infection, food allergy and eczema.
Allergic diseases have risen dramatically over the last few decades in Australia, and we now have the highest documented rates worldwide.
The hygiene hypothesis proposes that as a result of our clean lifestyles in Australia and other developed countries, babies do not come in contact with enough good bacteria and other microbes that encourage the development of a healthy immune system.
Without these good bacteria, the immune system may develop in a way that is prone to allergies and other autoimmune diseases.
BCG vaccine is used to prevent tuberculosis, also known as TB. Given at birth to almost all babies born worldwide, it is one of the oldest, most widely-used and well-tolerated vaccines.
BCG is a routine vaccine given to all babies in many developed countries, including Ireland and some parts of the UK and Europe. This vaccine is no longer routinely given in Australia, as we are fortunate to have very low rates of TB.
BCG vaccine has been found to have beneficial effects on the immune system over and above its protective effect against TB. Studies suggest that the vaccine may help prevent infection as well as reduce allergic diseases such as eczema, food allergy, hay fever and asthma.
There are also studies that suggest BCG vaccination protects against the future development of melanoma.
