One TB Vaccine in 100 years – yet more than one COVID vaccine in 100 days
In Pakistan, a healthcare worker listens to a child’s lungs for signs of pulmonary tuberculosis.

On the 100th anniversary of the world’s only vaccine for tuberculosis, the Stop TB Partnership has urged world leaders and other stakeholders to prioritise the development of an effective, safe and affordable tuberculosis vaccine by 2025. 

But there is a financial shortfall to achieve this goal, with only around a fifth of the target funding having been raised so far. In 2019, US$117 million was invested in TB vaccine research against a target of at least US$550 million per year over the next four years to achieve the 2025 deadline. In contrast, COVID-19 vaccine research received over US$100 billion in funding over the past year.

“What the world has achieved in the past year with regards to the development of safe and effective COVID-19 vaccines is astonishing and worth celebrating,” said Dr Lucica Ditiu, executive director of the Stop TB Partnership.

Ditiu noted that the same level of energy and funding that went into new vaccines for COVID-19 should also go into vaccines for TB, another airborne, deadly infectious disease that has been around for millennia and kills 4,000 people every day, including 700 children. 

“Today, we call on the world to provide sufficient financial resources and political will by 2023 to allow for the rollout of an effective TB vaccine by 2025. Lessons learned from recent pandemics clearly show that it is possible,” Ditiu added.

Carol Nawina, a TB survivor and person living with HIV noted that prior to COVID-19, TB advocates had come to the conclusion that there may not be a new vaccine again. 

“For me, it’s really outrageous that the world, for 100 years, could not come together and develop an effective vaccine for TB. But here we are, within two years, we already have several vaccines for COVID-19,” she told a briefing on Thursday convened by Stop TB.

Nawina, who is a Zambian, also said that Zambia and other TB-high burden countries should declare TB a national priority for investment and that political will is operationalised. 

“COVID-19 has shown us that we can do with investment. We must leverage the COVID-19 investment to end TB. The global community must now invest funds and allocate domestic resources for this purpose,” she added.

BCG ‘isn’t doing what we need it to do’

David Lewinsohn, professor of medicine at Oregon Health and Science University, and chair of Stop TB Partnership’s working group on new TB vaccines

David Lewinsohn, professor of medicine at Oregon Health and Science University, and chair of Stop TB Partnership’s working group on new TB vaccines, described the BCG vaccine that was first administered in July 1921 as a good vaccine that has been effective in preventing the really severe complications of childhood TB including meningitis and disseminated TB. 

“I don’t think the BCG vaccine has failed. One of the reasons why we have been reluctant to discard the vaccine is because it works in preventing severe forms of TB in children. It hasn’t failed, but it isn’t really doing what we needed it to do,” Lewinsohn said.

But the BCG vaccine has not been able to bring about dramatic reduction in the number of TB cases among the populations like the vaccines against measles, mumps or polio as a leading infectious disease worldwide, killing thousands of people, including hundreds of children, daily.

Lewinsohn said that there were 15 TB vaccine candidates in the pipeline currently.

In September 2018, the results a Phase 2b clinical trial were announced that showed GSK’s M72/AS01E candidate vaccine significantly reduced the incidence of pulmonary TB disease in HIV-negative adults with latent TB infection with an overall vaccine efficacy of 54%.

“Now, that was 2018, and working our way backwards, the actual discovery and development of that vaccine took place in the late 1990s. And so it really took about 20 years to go from vaccine development to the first promising results in humans, and we contrast that to the enrollment of the COVID vaccines which took something less than 100 days. Admittedly that benefited greatly from defense investments in SARS and MERS. But nonetheless, that’s a pathetically short timeline, ” Lewinsohn said.

In addition to upstream investments into TB vaccine development, Lewinsohn said there is also the need for far greater capacity to evaluate and license the vaccines to ensure equitable TB vaccine distribution.

A challenging disease for vaccine development

Even with the availability of funds and political will, in comparison with COVID-19, TB has been described as a challenging disease for vaccine development. 

While SARS-CoV-2 is highly transmissible and capable of causing disease in most individuals infected, the situation is different for TB where most people who get infected do not fall sick in the short term.

“So we need to think about vaccines in different contexts and it’s very likely we’re going to need more than one vaccine,” Lewinsohn said.

He noted that the vaccine that is efficacious among children may be different from the ones for adolescents. In the same vein, the vaccine that prevents infection may be different from the one that prevents people from falling sick.

“I think there’s really good science that supports vaccines for all of those indications, but it just highlights the idea that we’re going to need to pursue different vaccines with different indications as rapidly as we can,” the professor said.

In March 2021, Health Policy Watch reported that 12 months of COVID-19 have eliminated 12 years of progress in the global fight against tuberculosis. At Thursday’s briefing, Sahu Suvanand, Stop TB Partnership’s Deputy Executive Director said COVID-19 has been a major setback in the global fight against TB. 

“We are not on track to end TB,” he said.

He noted that dealing with the limitations of the BCG vaccination will improve the realisation of global TB goals. 

“It offers mostly variable or poor protection against other forms of TB. It particularly doesn’t prevent TB transmission, and disease in adolescents,” he added.

Going forward, he said the world needs to recover from the impact of COVID-19 and come back on track towards ending TB.

“It will require the existing tools to be applied at scale and with some innovations to get over the barriers that COVID has faced. Also, the new tools that are in the pipeline need to come in and be rolled out, and then we should be able to end TB by 2030,” Suvanand added.

Image Credits: Stop TB Partnership.

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