Tuberculosis (TB) is a dangerous airborne illness that has plagued humanity for centuries. Despite advancements in healthcare, it persists, necessitating the development of effective and sustainable TB vaccines. This article presents an exhaustive discussion on TB vaccines and their wide-ranging implications.
Tuberculosis is an infectious disease that mainly affects the lungs, and it has claimed countless lives over the years. Typically caused by Mycobacterium tuberculosis, it spreads from person to person through microscopic droplets released into the air by an infected person when they cough or sneeze.
TB Vaccines: The Card Against TB
The Bacillus Calmette-Guérin (BCG) vaccine is currently the only TB vaccine available. Named after its developers, Albert Calmette and Camille Guérin, it was first used in 1921 and remains in wide use today, primarily administered to infants in countries with high TB rates.
Efficiency of BCG Vaccine
The BCG vaccine has confered partial immunity, with variable and somewhat controversial effectiveness. Studies show that BCG vaccine reduces the risk of TB by 50% for a period of 15 years. Nevertheless, its effect differs among populations depending on geographical location, genetic factors, and exposure to environmental mycobacteria.
Challenges with the BCG Vaccine
Despite its extensive use, the BCG vaccine has faced challenges such as variations in its efficacy, the inability to prevent pulmonary TB in adults, besides not being recommended for immunocompromised patients due to the risk of disseminated disease.
New TB Vaccine Candidates
Efforts continue to produce more effective TB vaccines. Candidates include subunit vaccines, viral vector vaccines, and whole cell vaccines. MVA85A, the most responsibly tested vaccine candidate to date, boosts immune responses that have been primed by the BCG vaccine.
Deployment of TB Vaccines
Deployment of the BCG vaccine has remarkably reduced childhood morbidity and mortality. The vaccine is normally given to babies soon after birth in countries with a high incidence of TB.
Efficacy of TB Vaccines
Scientific evidence indicates that TB vaccines have considerably aided in curtailing TB cases. However, with the vaccine candidate still falling short of the 70% efficacy target set by the World Health Organization (WHO) for new TB vaccines, more needs to be done.
There is an urgent need for novel strategies to improve immunological memory and increase the durability of TB vaccines. These may include optimized antigen selection, development of novel adjuvants, improved vaccine delivery platforms, and strategies to modulate the microbiome.
The creation of an effective TB vaccine has been a global health priority. With progress in TB vaccine research and the advent of innovative technological platforms, the dream of a world free of TB seems increasingly attainable.