Why tuberculosis should be treated as a pandemic

On March 24, 141 years ago, German microbiologist Robert Koch announced to the world that he had discovered the cause of one of the oldest and deadliest diseases in history: tuberculosis.

Finding it of a bacillus

it opened the door to the search for a cure and a vaccine.

The investigation of the treatments has paid off and today it is curable in most cases, although, for this, it is necessary to have access to the appropriate drugs.

Without them, 45% of patients die.

However, the bacteria mutate and become resistant to the drugs, making it impossible to end the battle to develop new medicines.

Immunization is still a pending issue.

There is only one that dates back more than a century and has limited efficacy, although there are 16 new candidates in clinical trials, six of which are already in phase III, when the safety and efficacy aspects of the drug are robustly verified before it is released. its marketing.

Despite the progress, the data urges further progress in both fields: in 2021 alone (latest figures available) there were 10.6 million new cases and 1.6 million people died as a result of the disease, making it a the second deadliest infectious disease after covid-19, and the thirteenth leading cause of death in the world.

“It is time to recognize it as a pandemic, address it as an emergency and put an end to it,” calls for Peter Sands, Executive Director of the Global Fund for HIV, Tuberculosis and Malaria, on the occasion of World Tuberculosis Day which is commemorated in the anniversary of Dr. Koch's discovery.

“We have managed to eliminate it as a threat to public health in practically all the richest countries in the world.

And yet, we continue to allow millions of people to continue to suffer and die from this preventable, treatable and curable disease, ”he denounces.

In his opinion, "advances are being made at a snail's pace" in the fight against this ailment.

The incidence has declined globally by 2% per year from 2000 to 2020. But with the outbreak of the covid-19 pandemic that year, there was a rebound for the first time in two decades, with a 4.

In 2021, the highest percentage of new cases occurred in Southeast Asia, with 46% of the total, followed by Africa (23%) and the Western Pacific (18%).

The slowness and setbacks in progress, which have become even more evident with the speed with which covid-19 has been addressed, has an explanation, according to experts.

“Unless a disease threatens the population of rich countries, it is not even considered a pandemic.

But tuberculosis meets all the requirements to be judged as such," notes Sands.

The figures confirm his regret.

In 2021, the highest percentage of new cases occurred in Southeast Asia, with 46% of the total, followed by Africa (23%) and the Western Pacific (18%).

In Europe, 2.2% were registered.

"It is likely that by 2023 tuberculosis will kill more people in low- and middle-income countries than covid-19," predicts the expert.

Which would position it, once again, as the deadliest of infectious diseases, at least in these countries.

Every year, on this date, the WHO calls for redoubling its efforts, more funding and accelerating the fight against tuberculosis.

This anniversary he does it again under the slogan "Yes, we can end TB!".

Since it launched its latest study on the disease in October 2022, the data of which fell like a jug of cold water, some news has been revealed that raises expectations of returning to the path of progress.

One of the most encouraging has been the start, in December 2022, of immunization in sub-Saharan African countries with high incidence —Senegal, South Africa and Madagascar— with a vaccine designed and produced in Spain (MTBVAC) to test its efficacy.

The project is in phase III of clinical trials, which will last for five years, says Carlos Martín,

principal investigator of the Tuberculosis Vaccine project at the University of Zaragoza.

"We seek more than 50% protection, but our ideal would be, based on the experiments we have carried out on animals, to reach 80%," he explains.

He qualifies that what was verified in the previous phases "has served to demonstrate its safety and immunogenicity [ability of a drug to generate immune responses]".

But it is not the end of the road.

We must continue advancing to the next stage: “Now we must demonstrate that it is safe in the more than 7,000 babies who are going to be vaccinated;

half with the current vaccine (BCG) and the other half with the MTBVAC”.

He qualifies that what was verified in the previous phases "has served to demonstrate its safety and immunogenicity [ability of a drug to generate immune responses]".

But it is not the end of the road.

We must continue advancing to the next stage: “Now we must demonstrate that it is safe in the more than 7,000 babies who are going to be vaccinated;

half with the current vaccine (BCG) and the other half with the MTBVAC”.

He qualifies that what was verified in the previous phases "has served to demonstrate its safety and immunogenicity [ability of a drug to generate immune responses]".

But it is not the end of the road.

We must continue advancing to the next stage: “Now we must demonstrate that it is safe in the more than 7,000 babies who are going to be vaccinated;

half with the current vaccine (BCG) and the other half with the MTBVAC”.

Without a vaccine, it is clear that it will be practically impossible to eradicate it

Carlos Martín, researcher at the University of Zaragoza

The objective of completely ending tuberculosis by 2030, as established in the UN 2030 Agenda, would require a decrease in cases of between 4% and 5% per year.

“Without a vaccine, it is clear that it will be practically impossible to eradicate it,” says Martín.

The only one that exists, from more than a century ago, based on an attenuated strain of

(from cows), confers very limited protection against the pulmonary forms of the disease, responsible for its transmission.

The one developed by the team from the University of Zaragoza is the only candidate of the 16 in clinical trials based on a strain of

(from humans).

“What we do with the deletions contained in MTBVAC is to eliminate the virulence genes”, explains the technician.

This means that, without these genes, the bacillus does not have the capacity to attack its host and produce an infectious disease, but it does have an immunological reaction that will protect the person against future incursions of the pathogen.

"An attenuated tuberculosis strain in humans has never been approved," continues Martín, who hopes to instill enthusiasm for him in possible "Spanish financiers and philanthropists" for when the European funds they have insured run out.

“The idea is a vaccine with a single dose at birth, that is cheap and can be widely distributed, that is egalitarian.

The condition of the University of Zaragoza is that it be affordable”, underlines the researcher.

In this sense, the Galician biopharmaceutical company Biofabri and India's Bharat Biotech announced months ago an agreement to manufacture and distribute MTBVAC in the future, as soon as it has the necessary authorization, in more than 70 countries in Southeast Asia and sub-Saharan Africa;

including India, which suffers the highest burden with 28% of total new infections in 2021.

Barriers to access and drug resistance

An MSF technician analyzes samples in the laboratory of the drug-resistant tuberculosis hospital in Kandahar, Afghanistan.Lynzy Billing (Lynzy Billing)

Experience with diagnostic methods and treatments for tuberculosis shows that their existence is not a guarantee that they will reach their recipients.

In addition to the under-financing of the fight against the disease in the countries that suffer it the most —in 2020 it was 4,873 million euros, less than half (41%) of the global objective—, it happens that the impoverished population of the same does not always It has a nearby health center where you can go to complete the six months of medication until you are cured.

Irregular compliance with the regimen, among other reasons, leads to drug resistance.

And those resistant strains spread from person to person.

There are also tests and drugs to detect and treat multidrug-resistant tuberculosis.

But one in three patients does not access them.

Since December 2022, the WHO recommends the BPaLM regimen, that is, six months of bedaquiline (B), pretomanid (Pa), linezolid (L), and moxifloxacin (M).

A shorter and less toxic regimen than the standard up to now, up to 20 months and very painful.

“The results of the PRACTECAL study [on the BEaLM regimen] led by Doctors Without Borders showed cure rates of almost 90%, much higher than those obtained by the conventional regimen of 52%.

Likewise, it causes fewer side effects”, says Laura Moretó, an expert in the field from the medical NGO.

“But many countries still do not have access to some of the components, either because of their availability or because of their high cost,

as is the case of bedaquiline, which still has a patent and its price is estimated at around 250 euros per course of treatment”.

At least one of these stumbling blocks was demolished this Thursday in India.

Successful patent challenge for bedaquiline, to treat the form resistant to first-line drugs, by two tuberculosis survivors, Nandita Venkatesan and Phumeza Tisile

“The 2019 patent challenge for bedaquiline by two tuberculosis survivors, Nandita Venkatesan and Phumeza Tisile, has been successful,” MSF said in a statement.

Thus, the Indian Patent Office has rejected the attempt by the pharmaceutical company Johnson & Johnson to extend its monopoly in the Asian country over the drug, beyond the expiration of the primary patent next July.

In such a way that generic manufacturers will be able to produce generic versions of the drug as of 2023 and the US company "should not block the supply of the most affordable ones to countries with a high burden of tuberculosis," reads the document.

According to Moretó, "the impact for the patient is clear: the possibility of receiving a shorter oral treatment, better tolerated,

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