Old meds, new hope

The spotlight is on a 100-year- old tuberculosis vaccine for its potential to curb a variety of ills.

- NICKY PELLEGRINO

Many of us carry a small round scar on an upper arm to show we were vaccinated against tuberculosis when we were young. The BCG (Bacillus Calmette-Guérin) is the oldest vaccine still in continuous use. For more than 100 years it has been protecting children from this potentially fatal contagious disease.

Today, after a period of decline, tuberculosis cases are on the rise and it is now the deadliest infectious disease globally, surpassing Covid-19. While new vaccines are in development, the BCG remains the only one available.

Demand for the vaccine is further boosted by researchers exploring how it might be useful as a tool for training the immune system to prevent other conditions. It's already in use as a treatment for bladder cancer and has been shown to be protective against the influenza A virus. One trial even found that it can protect against long Covid if administered during the Covid-19 convalescence period.