Old Tuberculosis Vaccine Tested To Prevent Eczema

The very old tuberculosis vaccine could reduce the incidence of eczema in high-risk infants, according to a new Murdoch Children's Research Institute-led allergy study in Australia. 

The study was based on the idea that Bacille Calmette-Guérin (BCG) vaccine stimulates the human immune system to fight infections better and is less prone to allergies.

The initial study findings were published in the journal Allergy on July 26, 2021, and showed that a single dose of BCG-Denmark vaccine had a modest beneficial effect in preventing eczema in over 1,200 high-risk infants.

The study found that BCG vaccination benefit was greater in infants with two atopic parents, meaning those with hay fever, asthma, or eczema. In these infants, a single dose of BCG soon after birth reduced the incidence of eczema by about 25%.

Chief investigators Professor Nigel Curtis, Dr. Laure Pittet, and Dr. Nicole Messina undertook this research as part of the Melbourne Infant Study: BCG for Allergy and Infection Reduction, which is a randomized controlled trial to assess the effect of neonatal BCG vaccination on clinical allergy and infection outcomes.

At this stage, however, the authors noted there is insufficient evidence to recommend neonatal BCG vaccination for all infants to prevent eczema in the first year of life.

The research team continues following these infants over their first five years of life and is also looking at the effect of BCG on respiratory tract infections, allergies, and asthma.

The WHO recommends routine neonatal BCG vaccination in countries with moderate to severe tuberculosis prevalence. The reduction in childhood mortality may be due to epigenetic reprogramming of the nucleotide-binding oligomerization domain receptor. 

Furthermore, beginning September 2021, eligible babies born in the UK should be offered the BCG vaccine at 28 days or soon after birth.

BCG vaccine versions vary in the content of live mycobacteria. In addition, BCG-induced whole blood cytokines differed significantly by age, vaccine formulation, and concentration. Version include but are not limited to BCG-Denmark (Statens Serum Institute); BCG- Japan, BCG-India, BCG-Bulgaria. 

The BCG vaccine is not widely used in the United States, says the U.S. CDC.