Evaluation of DNA vaccines encoding M. Tb gene Bfrb and Mpt32 in mice model.

Tuberculosis (TB) is a life threatening infectious disease which is prevalent throughout the world. Mycobacterium bovis based Bacille Calmette-Gue´rin (BCG) is the only vaccine available against TB however, this (single) vaccine is not enough to eradicate it. Furthermore, numbers of researches from different parts of the World have shown its efficacy as variable. Hence other (better) vaccines like DNA vaccines are needed in addition to BCG in order to achieve desired goal of TB eradication. The current study was aimed to develop subunit based DNA vaccines against TB and to check their efficacy. Two constructs Bfrb-pND14 and Mpt32-pND14 were made and used as DNA vaccines. Endotoxin free DNA preparations were made and used in immunization studies. Twenty Balb/c female mice of age eight weeks were used in trial. Two experimental groups each comprising eight animals were used to inoculate Mpt32-pND14 and Bfrb-pND14 vaccines respectively. A group of four animals was used as negative control. Animals were bled through tail periodically and finally through cardiac puncture before euthanization. Antibodies were confirmed through dot blot and Agar Gel Immuno Diffusion test (AGID). All the animals immunized with both vaccines were found positive as tested through dot blot and AGID. The results of this study have indicated that both the M. tb genes have produced strong immune response in mice model through pND14 vector and proved themselves as good subunit based DNA vaccines.

A double blind community-based randomized trial of amoxicillin versus placebo for fast breathing pneumonia in children aged 2-59 months in Karachi, Pakistan (RETAPP).

BACKGROUND: Fast breathing pneumonia is characterized by tachypnoea in the absence of danger signs and is mostly viral in etiology. Current guidelines recommend antibiotic therapy for all children with fast breathing pneumonia in resource limited settings, presuming that most pneumonia is bacterial. High quality clinical trial evidence to challenge or support the continued use of antibiotics, as recommended by the World Health Organization is lacking. METHODS/DESIGN: This is a randomized double blinded placebo-controlled non-inferiority trial using parallel assignment with 1:1 allocation ratio, to be conducted in low income squatter settlements of urban Karachi, Pakistan. Children 2-59 months old with fast breathing, without any WHO-defined danger signs and seeking care at the primary health care center are randomized to receive either three days of placebo or amoxicillin. From prior studies, a sample size of 2430 children is required over a period of 28 months. Primary outcome is the difference in cumulative treatment failure between the two groups, defined as a new clinical sign based on preset definitions indicating illness progression or mortality and confirmed by two independent primary health care physicians on day 0, 1, 2 or 3 of therapy. Secondary outcomes include relapse measured between days 5-14. Modified per protocol analysis comparing hazards of treatment failure with 95% confidence intervals in the placebo arm with hazards in the amoxicillin arm will be done. DISCUSSION: This study will provide evidence to support or refute the use of antibiotics for fast breathing pneumonia paving a way for guideline change. TRIAL REGISTRATION: Clinical Trials (NIH) Register NCT02372461.