Cost-effectiveness analysis of MVA85 vaccine: a new TB vaccine candidate

Includes bibliographical references.Tuberculosis (TB) remains a major public health concern. The BCG vaccine is, currently, the only vaccine against TB and, although it provides some protection against disseminated forms of TB, its effectiveness in preventing primary infection and disease progression to pulmonary TB is highly varied. A number of potential new TB vaccine candidates have been identified and are, currently, undergoing clinical trials. One such candidate is MVA85A. This study aims to assess the potential cost-effectiveness of a new TB vaccine, the MVA85A vaccine. The study compares two TB vaccine strategies, from the perspective of the South African Government: i. BCG, given at birth, which is the current standard of care in South Africa; and ii BCG, given at birth, together with a booster vaccine (MVA85A) given at 4 months, which is the potential new strategy. The study employs Decision Analytical Modelling, through the use of a Markov model, to estimate the costs and outcomes of the two strategies. The cumulative costs and outcomes of each intervention are used to calculate the cost-effectiveness ratio (CER) (i.e. the cost per TB case averted and the cost per TB death averted) for each intervention. These two cost-effectiveness ratios are compared using an incremental cost-effectiveness ratio (ICER), which represents the additional cost per additional benefit received. The results of the cost-effectiveness analysis indicate that the MVA85A strategy is both more costly and more effective – there are fewer TB cases and deaths from TB – than BCG alone. The Government would need to spend an additional USD 1,105 for every additional TB case averted and USD 284,017 for every additional TB death averted. Given the disappointing results of the MVA85A vaccine clinical trial – showing an efficacy of only 17.3%, this study will predominantly contribute to establishing an efficacy threshold for future vaccines. Our research also contributes to the body of knowledge on economic evaluations involving new TB vaccines as - to the best of our knowledge - this is the first cost-effectiveness analysis conducted using trial data involving a novel TB vaccine and providing a direct comparison with BCG vaccination. Furthermore, it provides a standardized Markov model, which is relatively simple to adapt to local settings and, which could be used in the future, to estimate the potential cost-effectiveness of new TB vaccines in children between the ages of 0–10 years