Another Year and Another Respiratory Infection: 2022 Prospects for Tuberculosis Control in the Shadow of COVID-19

Right now, a highly transmissible respiratory infection is spreading across the world, thriving among marginalized populations and in poorly ventilated spaces. The infection can cause cough, fever, shortness of breath. The world is eager to forget about it and move on, yet the infection continues to cause mass sickness and death whether or not we pay attention.

No, not that one. We’re talking about the other respiratory plague of our time: tuberculosis (TB).

While the COVID-19 pandemic has understandably consumed global health attention and resources, TB has faded even further into the background of our collective consciousness. TB, unlike COVID-19, is characterized by long-term transmission and progression over the course of years and decades–not days and weeks. The TB burden rises as a slow tide, not a tsunami; it can therefore continue to kill en masse without ever feeling like an emergency. But until COVID-19 hit in 2020, TB ranked as the world’s leading infectious disease killer, causing 1.5 million deaths each year—overwhelmingly in low- and middle-income countries.

Until COVID-19 hit in 2020, tuberculosis ranked as the world’s leading infectious disease killer, causing 1.5 million deaths each year—overwhelmingly in low- and middle-income countries.

Last month the world commemorated World Tuberculosis (TB) Day with the theme “Invest to End TB. Save Lives.” But the needed investment is not forthcoming; expenditure on TB consistently misses the mark: in 2020, spending was less than half the $13 billion by 2022 target—and TB deaths increased in 2020 for the first time in more than a decade.

TB, once highly prevalent across Europe and North America, has largely been forgotten in the West but remains a heavy burden in low- and middle-income countries. Now, as rich countries vaccinate (and boost) their populations against COVID-19, lift restrictions, and slowly return to “normal,” we risk leaving low- and middle-income countries behind without sufficient vaccines, tests, and treatment capacity. Will TB history repeat itself with COVID-19 as rich countries move on?

COVID-19 has disrupted TB diagnosis and treatment

The emergence of COVID-19, and subsequent efforts to curb infection rates and respond to outbreaks, has diverted already limited focus away from TB control. Progress has been reversed: the 2021 WHO Global TB Report indicates that TB mortality has worryingly risen—and already vulnerable populations are at increased risk.

Case notifications of people newly diagnosed with TB sharply declined by 18 percent between 2019 and 2020. This might sound like good news—less TB!—but it likely just means that more cases are going undiagnosed because of the COVID-19 strain on health systems and health workers, coupled with fear of contracting COVID-19 at health facilities. A WHO study from March 2021 estimated reduction of 21 percent in TB care in 2020 – significant disruptions which could cause an additional 500,000 TB deaths.

Overall progress in the TB fight has stalled and reversed. Few End TB Strategy milestones for 2020 were reached; many did not even come close. How long will it take to make up for lost gains? Is the damage reversible? And how will we control if the frequency and severity of future pandemics increases?

Silver linings from the COVID-19 fight?

Despite this bleak picture, the COVID-19 pandemic may yet offer some silver linings for TB control—both in helping us directly address the disease and by inspiring us to “think big” about needed TB innovation.

We now have a better understanding of the spread and transmission dynamics for airborne diseases. Some of the same investments and strategies that helped with COVID-19—for example, better ventilation, especially in congregate living settings—could increase long-term respiratory safety across pathogens.

Some of the same investments and strategies that helped with COVID-19 could increase long-term respiratory safety across pathogens.

We’ve also seen with COVID-19 how fast-paced innovation can dramatically reduce the global disease burden. Thus far, innovations in TB prevention, diagnostics, and treatments have been severely lacking. We’re still forced to make due with a 100-year-old vaccine with limited effectiveness in preventing primary infection nor reducing transmission. We can do better with sufficient investment. Typical vaccine development timelines take 5 to 10 years, but COVID-19 vaccines came to market in under a year—a heroic but apparently achievable accomplishment if there is sufficient financing, collective will and collaboration.

We’ve also observed how rapid, self-testing for COVID-19 can transform diagnosis and care pathways—allowing people to prevent onward transmission and quickly begin effective therapeutics. We desperately need similarly simple and affordable tools for TB diagnosis, which currently requires burdensome blood, sputum, or skin tests. We think this is scientifically feasible in the short-to-medium term, and we’re currently working on an investment case to incentivize just this kind of innovation. Stay tuned!

And finally, we need better TB therapeutics. Recent advances in COVID-19 treatment have been a game changer for those with access; if taken early, Paxlovid reduces the chance of hospitalization by 88 percent. The good news is that TB is also treatable; the bad news is treatments are sub-optimal due a general ambivalence toward the disease at the global level, and a resulting lag in innovation to develop new therapeutics. Today, people with TB must take drugs for anywhere from six months to two years—and do so consistently—to avoid developing drug-resistant TB. Drug resistant TB can require more than 14,000 pills on top of daily injections for six months, depending on the severity of the case, putting significant burden on patients and health care systems. Though there have been several highly promising breakthroughs for TB treatment in the past decade (bedaquiline, delamanid, and pretomanid, to name a few) there’s a question of access and deployment.

CGD’s proposed market-driven value-based advanced commitment (MVAC) for TB is designed to produce a better therapy—one based on health technology assessment (HTA) dependent on country-specific conditions, commitment guarantees, industrial policy alignment, and a credible governance structure—by mobilizing private sector R&D investments based on market purchasing power in emerging economies. But we’ve also seen that therapeutics are worthless without broad access among populations in need, which is why the MVAC proposal is designed to ensure locally affordable prices for LMIC governments.

At baseline, TB control requires strong health systems

Many of the activities discussed in this blog—disease prevention, diagnosis, and control—are attributes of high-performing, well-funded health systems. And investments in TB programs, much like investments in control and prevention for any disease, have far-reaching, complementary benefits across health systems.

Strengthening health systems at the country and community level also builds in resilience so that when crisis situations arise, the existing infrastructure can absorb the shock, thus mitigating any detrimental impacts on TB and other care. The long-term nature of case management for TB (typically more than 6 months) requires stability and consistency in care, making care in crises all but impossible.

We’ve seen the consequences of this unfolding in real time in Ukraine, a country with an already high rate of TB infections—32,000 people develop active TB per year, one third of which are drug resistant. The combination of COVID-19 and Russia’s invasion, and consequent implosion of the public health system, have disrupted treatment for thousands and experts have warned of a potentially devastating TB problem in Ukraine.

Concluding thoughts

The current situation for TB is bleak, but the prospects can be bright if we decide to invest and break the cycle of panic and neglect. Investment in strong health systems—including real-time data and dashboards—is critical to protect against outbreaks of both existing and emerging infectious disease threats. We still do not know the extent of the damage COVID-19 disruptions have had or will have on progress towards TB control, but as the world pivots from recovering from COVID-19 towards preparing for new health threats, diseases like TB should not be left behind.