The tuberculosis vaccine currently in use, Bacillus Calmette-Guerin (BCG) is an invention of the 1920s. Tuberculosis is a very dangerous disease that kills as many as two million people every year. The drug was considered to have so many flaws that countries like the United States never adopted it.
It is now thought that the countries that refused to adopt BCG could have made the wrong choice, as revealed by a recent study. The study published in the International Journal of Epidemiology reveals that the vaccine confers protection on the patient longer than previously thought. Heading the study is an epidemiologist at the London School of Hygiene and Tropical Medicine, Dr. Punam Mangtani.
Health officials that are making plans to drop the vaccination like Central Europe and Latin America might need to reconsider their position. The risk of dying from tuberculosis is higher at infancy, decreases in childhood and rises again after puberty.
When working with BCG, timing is of the essence. This is because the effect fades after a few years and booster shots will not restore its efficacy. The World Health Organization advises that in countries where tuberculosis is widespread, the vaccine should be given at birth.
BCG is injected through the skin and leaves a small round scar. Dr. Mangtani used Britain as a case study, a choice that must have been tied to the country’s history with the vaccine. Up until 2005, when its use was discontinued because of a large decline of disease incidence, BCG was routinely given to 13-year-olds.
Dr. Mangtani compared the rate of tuberculosis in 1,800 Britons who were born between 1965 and 1989. Her studies revealed that those vaccinated as teenagers had half the chance of contracting the disease in the next 20 years of their life when compared to those who had never been vaccinated.
Anti-social habits like alcohol abuse and exposure to prison or homeless conditions and poverty tend to increase the chance of contracting the disease. The effects of BCG wane after 20 years, so much so that the risk is as much as those who have never been vaccinated.
Many countries like the Netherlands and the United States use their immigration regulations to keep tuberculosis away from their country. They conduct frequent testing and treat those who have it. Tuberculosis is known to be caused by Mycobacterium tuberculosis. The BCG was previously thought to confer protection for about 10 to 15 years, so this new discovery is quite a relief. Dr. Punam said:
“For those who had the BCG at school, knowing that it lasts longer than the assumed is reassuring. They are a bit more protected than the originally thought. This helps support a vaccine that is not often considered as being as important as some of the other infant vaccines.”
Source: The Guardian
It is unfortunate that, although tuberculosis is preventable, it is still a major cause of death mainly affecting the lungs. It is estimated that about two to three billion people in the world are infected with the disease, with 10% becoming ill.