An eager trial participant in the MVA85A phase IIB infant trial in South Africa.
Professor Helen McShane writes from the frontline of efforts to develop the first new TB vaccine in 90 years.
The current tuberculosis vaccine that many of us will remember receiving as a child, Bacille Calmette-Guerin (BCG), was developed 90 years ago, when movies were silent and George V was King of England.
BCG is one of the most widely administered vaccines globally and yet it has made little impact on the global tuberculosis burden. However, great progress has been made in the past 10 years in the search for a new more effective TB vaccine and today we are closer than ever to realizing this dream.
At the Jenner Institute at Oxford University, we have developed what is now the most clinically advanced new TB vaccine in the pipeline, MVA85A.
This vaccine candidate is being tested in two Phase IIb proof-of-concept clinical studies with broad support from a global network of research groups and funders, including the Wellcome Trust.
The first of these trials began in July 2009 in South Africa at the South African Tuberculosis Vaccine Initiative (SATVI) of the University of Cape Town on the Western Cape. The trial reached full enrollment in April 2011, with nearly 3,000 infants participating – making it the largest trial to date of a new TB vaccine candidate. The results will be announced in the beginning of 2013 and they will provide important safety, immunogenicity and efficacy data on MVA85A.
No matter the outcome, this will give our scientific community some key insights into the disease and form a major building block to discovering the vaccines needed to prevent and ultimately contribute to our goal of TB elimination.
Trial participants and their families fill the waiting room at a clinic in
Khayelitsha, South Africa for the Phase IIb study in adults living with
HIV.
The UK has played a pivotal role in supporting our research, and enabling our candidate to enter advanced clinical trials in various populations. Funding for the trials has been provided by the Wellcome Trust, in partnership with Aeras and the Oxford Emergent Tuberculosis Consortium (OETC), and the UK Department for International Development (DFID).
Working with the same partners and the Medical Research Council (MRC), Gambia, we are also conducting a clinical trial taking place in Senegal and South Africa looking at this candidate’s safety, immunogenicity and efficacy among adults living with HIV.
This trial, which began in August 2011, is receiving a majority of financial support from the European and Developing Countries Clinical Trial Partnership (EDCTP).
The current BCG vaccine is not recommended for people living with HIV and a core part of the strategy is to find a vaccine that is safe and effective in this population.
This is important for a new TB vaccine since tuberculosis is the cause of one in four HIV deaths. In places where TB and HIV are fueling each other, a TB vaccine safe and effective for people living with HIV is essential.
In developing a promising vaccine, we have made major progress. But there are challenges too. Tuberculosis vaccine science is especially difficult; mainly because there is still so much we don’t know about TB. There are no proven correlates of protection to help us determine what immune response the vaccine should emulate, and no effective animal models on which to base our research. These two pivotal clinical trials will therefore provide useful, relevant and critical data for TB vaccine scientists as we move forward to create the best vaccine possible.
Vaccine research and development is costly too. As we continue to make progress, clinical trials will become larger and exponentially more expensive.
The fathers of infant trial participants confer with a SATVI nurse.
There is a lot of work to be done between finding a viable candidate and ensuring future vaccines are affordable and accessible to all who need them. But there is commitment to doing this too. The UK Government has been a driving force in our work by making the development of a TB vaccine part of its global poverty reduction priorities. We are grateful for their continued partnership.
I am pleased to be on the cutting-edge of research in this challenging field, and proud to be from a country that places such an emphasis on indispensable scientific studies such as these. I hope that in my lifetime we will see the discovery of a new TB vaccine that will create a better future for millions of people affected by TB.
Helen McShane
Helen McShane is Professor of Vaccinology at the University of Oxford and a Wellcome Trust Senior Clinical Fellow.
Image credits: Aeras
Filed under: Biomedical Sciences, Fellowships, Guest posts, Health, Infectious Disease Tagged: BCG, BCG vaccine, Dr Helen McShane, Helen McShane, HIV, HIV/AIDS, TB, Tuberculosis, University of Oxford, Vaccine, Vaccinology
