‘Why do we have a COVID-19 vaccine before a TB vaccine?’ and other tough questions on #WorldTBDay
This World TB Day, international expert José Luis Castro answers the six tough questions about TB. Health-e News editor Amy Green asked what the real impact of COVID-19 on tuberculosis (TB) has been, why TB doesn’t have a vaccine for half a century, and why TB funding pales in comparison to funding for COVID-19.
Before the advent of COVID-19, tuberculosis (TB) was the world’s leading infectious disease killer. Yet, raising public awareness about the disease has remained difficult. Each year, the world marks World TB Day on 24 March.
In 2019, TB still needlessly killed 1.4 million people a year and about 10 million get sick with the disease each year, according to the latest estimates from the World Health Organisation.
“TB remains one of the world’s deadliest infectious killers. Each day, nearly 4000 lose their lives to TB and close to 28,000 people fall ill with this preventable and curable disease. Global efforts to combat TB have saved an estimated 63 million lives since the year 2000,” the WHO reported in the run up to this year’s World TB Day.
But COVID-19 has threatened the TB fight’s progress as well as the WHO’s international goal End TB, to end the epidemic by 2035. According to the WHO, this “is especially critical in the context of the COVID-19 pandemic that has put End TB progress at risk. Our modelling suggests that a 50% drop in TB case detection over 3 months could result in 400,000 additional TB deaths this year alone.”
The COVID-19 pandemic set the fight against TB fight back 12 years. The race for the COVID-19 vaccine has highlighted just how slow the decades-long wait for the TB vaccine, as Stop TB has pointed out.
These issues have raised difficult questions that Health-e News editor Amy Green put to José Luis Castro, president of the global health organisation Vital Strategies and a former executive director of the International Union Against Tuberculosis and Lung Disease. Castro also shared interesting theories about leveraging mechanisms created by COVID-19 to enhance the fight against and eradicate the disease.
Amy Green: What has been the impact of COVID-19 on TB?
José Luis Castro (JLC): The impact of COVID-19 on the TB response is going to be felt for a long time to come. TB diagnosis and treatment in high-burden countries dropped dramatically in 2020, reversing years of progress. Some of this was due to a repurposing of GeneXpert machines, which are typically used to diagnose TB, for COVID-19 testing and some due to enforced lockdowns restricting access to TB treatment and services. Experts estimate as many as 400,000 additional TB deaths may have occurred in 2020 and some of those will also include TB health care workers who were redeployed to the COVID-19 front lines.
AG: In 2020, COVID-19 surpassed TB as the world’s top infectious killer but as we transition to COVID-19 recovery, we can, unfortunately, expect to a return to even higher rates of TB infection and mortality? What lessons can we learn from COVID-19 to improve the TB fight?
JLC: I’d turn that question on its head. The tools and strategies employed in responding to the current pandemic—trace, test, isolate—are ones we’ve been implementing successfully for years in response to TB, as well as HIV.
But COVID-19 has demonstrated how much we can accomplish with enough political will—and the funding that results.
AG: Why do we still not have a new TB vaccine and the disease has been around for centuries while we had a COVID-19 vaccine within a year of the disease being discovered?
JLC: We do have the BCG vaccine for TB, discovered 100 years ago, but it doesn’t prevent respiratory disease, which is the most common form of TB in adults. It is 70% to 80% effective against the most severe forms of TB, such as TB meningitis, in children. We’ve long needed a new and better vaccine for TB—100 years is an outrageously long time. But COVID-19 has demonstrated how much we can accomplish with enough political will—and the funding that results.
AG: Tell me a bit about the shortfall in TB funding. Why does TB attract such little funding yet it still affects so many lives? And why does COVID-19 attract so much more investment from varied sources?
JLC: The missing link for TB has been its historical lack of funding, especially in research and development. It’s why diagnostic tools for TB are antiquated compared to those for other diseases, why new medicines to cure TB are, for the most part, not a priority for drug development. It’s why treatment takes months.
Currently the annual shortfall for TB research and development is around US$1.3 billion, exacerbated by an absence of incentives for the pharmaceutical industry to invest in the disease.
The upheaval cause by this pandemic drove an unprecedented level of political will. The real-time and potentially long-term disruption to national and global economies activated a level of public and private commitment and funding that helped drive coordination for vaccine research, testing and development at a record pace.
COVID-19 has demonstrated just how interconnected we all are. No one is safe until we are all safe. We can see our fragility and vulnerability to a deadly virus that is very, very easily passed from person to person. That’s a new experience for most people. We need to seize this moment and make the case for investing disease control.
AG: What are the most powerful tools and strategies we should be adopting for TB in a time of COVID-19?
JLC: There’s a lesson here for the TB world. Unlike COVID -19, we do have treatments that can both prevent, treat and cure TB for most people. We need to up the ante when it comes to tracing and testing. COVID-19 has shown how important it is to slow down a global pandemic. We can slow down TB too.
AG: Why can’t we eliminate TB, modelled on the COVID-19 Accelerator and COVAX for instance?
JLC: There is no reason we can’t.
We’ve seen how fast the access to COVID-19 Tools (ACT) Accelerator—set up by the WHO and partners—has facilitated the manufacture and delivery of 120 million high-quality rapid antigen diagnostic tests to countries that lack the laboratory facilities or trained health workers to implement PCR tests. As many as 500 million tests are planned for distribution before October 2021. This feat was accomplished in months; by contrast, it took five years for a similar facility to produce the first WHO-approved rapid diagnostic test for HIV.
ACT’s vaccines pillar— also known as COVAX—is working for global equitable access to COVID vaccines, shining a light on the inequity of vaccine access between rich and poor countries thus far 30 million vaccine doses have finally been distributed to low- and middle- income countries—compared to the 100 million and counting in the United States alone—but it is clearly insufficient.
Both these initiatives are exciting because they embody the ideas of equity and evidence-based science and recognise just how interconnected we all are. The vaccine debate of late has not just been about the right of all people to access a vaccine regardless of where they are born. It has been just as much about the scientific need to do so: a failure to vaccinate or eliminate disease in one country will have an effect everywhere else.
The same is true for TB: TB anywhere is TB everywhere. In this interconnected world, none of us are safe until all of us are safe. Out of crises, new opportunities can arise. We’re at a defining moment in infectious disease control. We need to seize the moment and take real action.—Health-e News