TB has vaccine lessons for Covid

In the early 1900s, a leading cause of death in places like the United Kingdom was a lung disease called tuberculosis (TB). What has happened since is an important warning for how the world should be responding to Covid-19 and any future pandemics. Let me explain. Back in the 1800s, TB was known as consumption. It was thought to be hereditary and was romanticised as bestowing some sort of spiritual purity on its sufferers. Then, in 1869, Jean Antoine Villemin showed rabbits got sick if injected with bits of lung from people who had died of TB. A little over a decade later, Robert Koch discovered the bacterium responsible, which he called Mycobacterium tuberculosis.

TB wasn’t hereditary. It was an airborne bacterial infection. Treatments sprang up, from sending the sick to sanatoria, to collapsing their lungs to give them a ‘‘rest’’.

Then came the discovery of antibiotics – medicines that kill bacteria. Streptomycin in 1944, isoniazid in 1952, ethambutol in 1961, and rifampicin in 1965.

Unfortunately, the TB bacterium has a waxy outer coat that makes it hard to kill. There’s no two-week course of a single antibiotic to treat TB. Instead, it’s six months using a combination of these four.

There have been two main problems with TB treatment being a six-month-long drug cocktail. The first is that most people start to feel better within a few weeks. Also, these drugs can have nasty side effects. Both mean some people stop taking their medication too soon.

More important has been a lack of access. In some places, people were only given one or two of the drugs.

And the result? The emergence of multi-drug resistant strains of the TB bacterium that require people to be hospitalised for months or years and treated with an even bigger cocktail of antibiotics.

Some countries turned TB into an even bigger problem by taking care of their own instead of doing all they could to protect all humans. The same is happening with Covid-19.

Without equitable access to Covid vaccines in the places that need them most, we run the risk of variants emerging that make the vaccines useless. More infectious variants are already evolving in countries that aren’t using all the tools in the toolbox to stop the virus from spreading.

Yet even now, the pharmaceutical industry and many highincome countries are blocking efforts by India and South Africa to mass manufacture vaccines or develop copy-cat versions.

TB taught us a lesson. None of us are safe until we are all safe. We’d be fools to let this pandemic play out the same way.