TBVI: Annual report: Choices in TB vaccine development

Tuberculosis takes approximately 1.3 million lives per year. It’s not only a huge cost to humanity, but also affects economies worldwide, and not only in developing countries. According to very conservative calculations, the direct costs of TB in the EU add up to about € 537 million per year. With the threatening rise of Multi Drug Resistant (MDR) TB and Extensively Drug Resistant (XDR) TB in the whole world, it is likely that these costs will increase in the near future.

Several types of new vaccines

The disease cannot be eliminated without new vaccines, according to several WHO studies. Therefore TBVI, together with over 50 research partners, is working on the development of several types of new TB vaccines and biomarkers (indicators used to monitor the efficacy of new vaccines). Vaccines are needed to protect children, adolescents and adults from getting ill from TB, and we need therapeutic vaccines which are able to shorten the long and burdensome treatment of patients, especially those with MDR and XDR TB.

Portfolio management

In the past years, dozens of vaccine candidates have been developed in laboratories and more are currently being developed. Many of them are about to enter, or have already entered the (pre)clinical stages of development, which are very expensive and for which only limited funding is available. Therefore TBVI introduced the method of portfolio management: a very efficient and effective method of advancing a vaccine through the pipeline. It is a quality decision-making process that seeks to maximise probability of success against acceptable cost and risk.

Select the best candidates

According to Jelle Thole, Executive Director of TBVI, this approach involves the use of priority setting and entry criteria to select the most promising candidates and to allow entry to new vaccine candidates so as to diversify the portfolio. “Priority setting aims to select the best candidate(s) for further development and down select others that seem less promising. The main criteria being used for comparison are technical feasibility, timelines of development, access conditions, projected health impact, commercial risks and prospects of the candidate.”

Big challenges

“But ensuring that new promising candidates gain admission to the portfolio, is essential as well,” he continues. The development of a well-balanced and diversified portfolio is a process which builds from a continuous flow of good scientific concepts, molecules or candidate vaccines into a decision-making process. The big challenges facing TB vaccine development are insufficient understanding of protective immune mechanisms, the lack of correlates of protection, and the poor predictive value of animal models. Several candidate vaccines in the current TB vaccine portfolio are based on the concept of critical antigens and desirable immune responses. TBVI wants to diversify the current portfolio by acquiring vaccines with novel effector mechanisms, so as to increase the chance of success.

Global TB Vaccine Partnership

Together with others, TBVI is endeavouring to optimise the results of the scarce global funding that is available. Jelle Thole: “With Aeras, the European Commission, the European Investment Bank, the Bill & Melinda Gates Foundation and the EDCTP, we have been working to initiate a Global TB Vaccine Partnership. This GTBVP aims to create a global portfolio approach for the development of new TB vaccines. Working this way, we can maximise the probability of success at acceptable cost and risk by supporting only the best vaccine candidates at each stage of development in a global portfolio. We are very much looking forward to the next steps in realising this global approach.”

Other items in the annual report:

• Interview with Governance Board member Michèle Boccoz, French ambassador to Croatia
• TBVI strategy: Vaccines for all people
• Highlights of 2013
• The fight of a German patient
• Interview with Shobha Shukla, a journalist in India

Read the whole annual report.

Source: TBVI