Four Key Prevention Strategies to End TB in our Generation

The World Health Organization estimates that each year, 10 million people get sick with tuberculosis (TB), causing 1.5 million deaths. Reflecting on World TB Day, our experts weighed in on four key strategies to prevent TB acquisition, transmission, and disease progression.

1. Accelerate TB Vaccine Development

There is renewed interest and possibility in the development of new TB vaccines, as highlighted during the recent 6th Global Forum on TB Vaccines. Currently, only one vaccine, BCG, is licensed for use against TB. BCG protects against severe forms of TB in infants and young children—however, it is only effective for this age group, leaving adolescents and adults unprotected, and contributing to ongoing TB transmission in their communities.

While it has been over a century since any new TB vaccines have been introduced, there is now reason for optimism. Nine new TB vaccine candidates are in Phase IIb and Phase III trials, with other candidates in the pipeline, many of them targeting adults and adolescents. New vaccine candidates for at-risk populations, including people living with HIV (PLHIV), and younger children are also in consideration. Advocates are robustly calling for community engagement in vaccine trials, and for early and ongoing planning for equitable access once a new TB vaccine is available.

The comparisons between TB vaccine development and COVID-19 vaccine development are inevitable and informative: in less one year, a COVID-19 vaccine was able to move through the phases of development and trial to approval, while the current TB vaccine candidates have been in process for years. Unprecedented public and private financing has supported COVID-19 vaccine research, development, and manufacturing scale-up. The rapid advances made in the development and roll-out of safe and effective vaccines for COVID-19 show that political commitment backed by massive investments can lead to faster access to life-saving vaccines.

The Global Forum on TB Vaccines highlighted that increased funding and increased attention are essential to progress. While funding for COVID-19 vaccines research in 2020 reached nearly $100 billion, that same year, funding for all TB research was <0.1% of that, at $915 million.

The COVID-19 vaccine experience challenges TB researchers, advocates, and public health leaders to think differently to replicate the successes achieved. As new TB vaccines get closer to reality, we must push harder for more funding for vaccine development, for earlier inclusion of government and community partners to prepare for rollout, and for better preparation to ensure equitable access for those at highest risk for TB.

2. Expand Contact Tracing

People exposed to TB through household contact should be prioritized for screening so they can be started on treatment to prevent infection or progression of disease.

In contact investigation, health workers systematically identify and reach out to contacts of a TB index case to ask them about signs of TB, assess any symptoms, and refer for further evaluation and treatment initiation as needed.

According to the recent USAID Report to Congress on the Prevention of Tuberculosis, data available from USAID TB priority countries shows a large increase in the number of contacts screened. Between 2018-2019, this number went from just over 1.7 million people to nearly 4 million people. Further, health workers were able to achieve this number despite other setbacks associated with the pandemic, perhaps due to the overlap with COVID-19 contact investigation efforts. Increased contact investigation efforts mean that greater numbers of people at high risk for TB can be linked to care to prevent TB infection and disease.

3. Scale-up TB Preventive Treatment, Especially for Household Contacts

TB preventive treatment (TPT) provides a course of treatment to at-risk clients and those with latent TB infection medication to prevent TB disease progression. Priority populations for TPT include people living with HIV (PLHIV), children under 5 years who live with a person with TB disease, and adolescents and other household contacts. Even if these individuals have been exposed to TB, if they take a TPT regimen, their chance of developing active TB disease is greatly reduced.

Countries agreed to reach 30 million people with TPT by 2022 at the 2018 UN High Level Meeting (UNHLM) on TB. Shorter TPT regiments and increased political attention and resources have contributed to significant progress: the target for reaching PLHIV was surpassed in 2021, with 7.2 million PLHIV initiated on TPT.

Children, however, continue to lag behind. Globally we are only at 29% of the pediatric TPT target. In addition, we need concerted efforts to reach more contacts above age 5, for whom only <2% of the target has been reached.

Rates of TPT completion have been tracked more consistently since 2018, including in USAID’s TB priority countries. Despite the COVID-19 pandemic, results for TPT completion in these countries improved significantly between 2019-2020, with an increase from just over 1 million people reported as completing treatment, to nearly 2.8 million. In fact, experts think that adjustments necessitated by COVID-19, such as telemedicine, remote adherence support, and increasing the amount of medications dispensed at a time, may have helped clients complete TPT at higher rates.

4. Strengthen TB Prevention Data Collection and Use

At the 2018 UNHLM on TB, USAID launched the Global Accelerator to End TB to increase commitment from, and build the capacity of, governments, civil society, and the private sector to accelerate countries’ progress in reaching the global targets.

One of the first activities launched under the Accelerator was the TB Data, Impact Assessment and Communications Hub (TB DIAH) project to improve and harness existing data and knowledge sharing on TB worldwide. Routine data collection and use is another key contributor to TB prevention efforts. For instance, the formal collection and reporting of information relating to the approaches described above are relatively new through WHO’s recently introduced “Contact Investigation Coverage” indicator and governments’ increased attention to the TPT completion indicator. Systematic use and inclusion of these data in high-level reports such as the USAID Report to Congress on the Prevention of Tuberculosis help ensure continuing political commitment and resource allocation.

Written by Sabrina Eagan and Nikki Davis