WHO's Jeremy Farrar says he's optimistic about tuberculosis. Here’s why

Tuberculosis — the world’s number one infectious disease killer — remains hard to treat and does not have an effective vaccine to protect adults from the disease. However, the robust pipeline of tuberculosis vaccines can provide hope for people affected by it and those who have been working to end the disease. One of the most talked about vaccine candidates, the M72 vaccine showed a 50% efficacy in preventing pulmonary TB disease in a phase 2b trial. The Bill & Melinda Gates Foundation and Wellcome this year announced $550 million in funding to support phase 3 clinical trials of the vaccine in more than 50 trial sites in Africa and Southeast Asia. It will take years for the results of the trial, and the vaccine won’t likely be 100% effective, but it can provide a huge amount of information about TB, and inform the development of the next generation of vaccines, said Jeremy Farrar, the chief scientist at the World Health Organization. “I have never been more optimistic in TB that in this decade we’ll have tools that will transform it,” he told Devex. But it’s not just about developing new tools. Farrar shared how the development of a new TB vaccine also provides an opportunity for change in the equity debate. But trust must be built now for an effective rollout in the future before a safe and effective vaccine is found. The text below has been edited for length and clarity. You said this is a moment of hope for TB. Is this because of the M72 TB vaccine candidate? M72 is the most advanced, but no, it's much broader than that. … I think the pipeline is stronger than it's ever been in my professional career. But also whatever the results of the M72 vaccine, which we won't know for three, four, five, whatever years, you will also learn a huge amount about TB, and that will inform the development of second generation vaccines. I think M72 will work. I think it'll be safe. I don't think it'll be 100% effective. And it'll be the first generation of vaccines. But at some moment, I think if you look across the history of vaccine development, clinical medicine, [and] public health, you need that moment of hope. If we look at HIV now … when it started, we had nothing. I remember working in a hospital in London, and a lot of young people came in, and we really could do nothing for them. And then there started to come treatments. Now those treatments are not used now. They've been superseded by better treatments. But they were critical in instilling hope into a community that had nothing, and that you could see a way that HIV would be changed from a death sentence to something that was difficult but manageable, if you could get access to the therapies. Malaria [is] the same. Again, in my 18 years living in Vietnam, I did a lot of work in malaria and there was a lot of malaria drug resistance. And then we developed the Chinese herbal drug, artemisinin, and then combination therapies, then insecticide bed nets. Now malaria vaccines are starting to come through. So you need these moments of hope, because otherwise I think patients, their families, the scientific community become nihilistic. Are there other promising candidates in the pipeline for TB vaccines and treatments? I don't think in my professional life or even life we will have a 100% effective TB vaccine. So we're going to have to always use TB vaccines with other interventions — behavioral change, infection control, early testing, early diagnostics, better treatments. So it is going to be part of a package. And you must, I think, see it together rather than thinking we're going to have a magic bullet that will be the answer to everything. That's why I think the community needs to come together to not argue just for treatment, or just for eradicating poverty, or just for behavioral change, or infection control, or vaccines. It's going to be the combination of all of those that's important. But on the treatment side, I think that the development of shorter course treatments is game changing, and I think there will be more drugs developed now. And then on the vaccine side, there's the M72, but then there are other constructs that have been tested now in earlier phase development. The mRNA approach that gave us the COVID vaccines is one approach, but there are others as well. So I have never been more optimistic in TB that in this decade we’ll have tools that will transform it. There’s a lot of excitement for new tools. But do you see challenges in terms of achieving equity for a future TB vaccine? Inequity didn't start with COVID, and it didn't finish with COVID. You can't have a conversation in global health now where equity isn't one of the first topics discussed. And that's progress. For tuberculosis, in particular, I think that there is an opportunity. The vaccine M72 is being developed with philanthropic money from the Gates Foundation and from Wellcome Trust in South Africa, in Indonesia, in Malawi, in Kenya, in Vietnam, [and] many countries, with other similar studies being done in India, and I hope in the future in central South America. So this is a global enterprise. And the ownership of that won't rest in Washington or Paris or London. This is something which, in my view, could actually transform the equity debate, because this can help sustain the technology transfer that the vaccines are not researched, developed, and manufactured in the global north, but their research developments, the clinical trials, and the manufacturing will be in the so-called global south. Will the manufacturing of M72 take place in low- and middle-income countries where the trials are happening? The trial itself … will be using the M72 vaccine that already exists. But the technology transfer, the discussions have been happening for some time now. And GSK deserves great credit for producing and running the initial studies to phase 2 trials and 20 years of investment in this vaccine. But then partnering now [is] being done by the Gates Foundation, the countries, and the Wellcome Trust. That allows you to now see this as a totally different vaccine, with a center of gravity in the countries that are doing the trial, the future manufacturing being in the countries doing the trial, and the ownership of this resting in the countries with endemic disease. Now that's game-changing. And it also helps sustain the scientific infrastructure, the regulatory environment, and the manufacturing [for] TB. Do you see a need for Wellcome and the Gates Foundation to have access conditions in their funding for the development of this vaccine? That's been a big part of the negotiations being done in good faith. I mean, they’re complex negotiations. And the Gates Foundation led this with GSK. COVID is not the only pandemic. TB is also a global pandemic. But of course, the vast burden of disease is in parts of the world in middle- and low-income countries. But it's not exclusively there. There is a huge TB problem in parts of Europe, [a] huge TB problem in parts of North America, and in Central and South America. But those access requirements and future access equitably and price has been a huge part of the negotiations throughout. You said the next TB vaccines will probably not be 100% effective. Do you see challenges in rolling out something that's not perfect? How can this be addressed? I think at the heart of what you're asking … is trust. And trust has been challenged in the last three years in many parts of the world. But I think trust is built over years — decades. And you build trust to last. And so the questions about what is this vaccine? Why is it being used? What is tuberculosis? Where is it being manufactured? Who's paying for it? Those need to not wait until you have an answer and you have a safe and effective vaccine, but to be part of our culture all the time. TB … where it's endemic, is such a part of the discussion in communities. In high-transmission countries, everybody knows somebody with tuberculosis. And people can see the devastation that it causes, the health devastation, the devastation to families, the stigma attached to it still, the impact on education or jobs. But you don't build this trust in a crisis.