Towards new tuberculosis vaccine

The History of Tuberculosis and Bacillus Calmette–Guérin Vaccine in Iran

“…IL-4-producing Th2 cell responses may predominate in these patients due to exposure to non-tuberculous mycobacteria (NTM) and/or helminth infections. Resultant IL-4 production and regulatory T-cell development may negatively regulate generation of Th1 type cells that could potentially contain TB infection, thereby leading to active disease and vaccine failure (12,18,(21)(22)(23). In recent mouse studies, CD4+ regulatory T-cells induced by BCG appeared to down-regulate effector T cell activity in mice infected with a virulent W-Beijing TB genotype; a finding with implications for BCG vaccination against highly virulent circulating TB strains (24).…”

“…There are different rates of BCG efficacy in different parts of the world from 0 to 80% (17). Factors responsible for the variable efficacy of BCG vaccine in adults, particularly in developing countries such as Iran, include; virulence of different Mtb strains, storage conditions and resultant viability, strain differences, loss of genes and the methodology of studies conducted in different regions (12,14,18). The BCG vaccine has different efficacies in endemic and non-endemic areas.…”

Evaluation of the overall IFN-γ and IL-17 pro-inflammatory responses after DNA therapy of tuberculosis

“…The reactivation of the disease and improper treatment can cause the death of the patient due to chronic inflammation that destroys the lung parenchyma. 1 Both factors are not rare to observe because active tuberculosis is associated with a patient's poor immunological condition. Additionally, the long period of treatment is difficult to complete and potentially causes the development of multi-drug resistant (MDR-TB) and extensively drug-resistant (XDR-TB) cases of tuberculosis.…”

An Update on New Vaccines for Tuberculosis

“…Besides that, apoptosis of the cells is caused by CD 8+ T-cells also plays an important role in TB infections [7]. Though the mechanisms of the immune system controlling the TB bacilli are not well understood, scientists believe it is the cell-mediated immunity that plays an important and critical role [12].…”