El Sarampión Regresa: Vacunas, Miedo, y la Enfermedad Que No Olvidó

And then in 1963, a virologist named John Enders and his team developed the first measles vaccine, and within a generation, that number collapsed.

La verdad es que la vacuna del sarampión es uno de los grandes logros de la medicina.

The measles vaccine is one of medicine's greatest achievements.

En los años noventa, la Organización Mundial de la Salud empezó un programa global muy ambicioso.

In the nineties, the WHO launched a very ambitious global program.

En 2000, el sarampión mató a unos quinientos cincuenta mil niños.

In 2000, measles killed around 550,000 children.

En 2016, ese número bajó a ochenta y nueve mil.

By 2016, that number fell to 89,000.

Una reducción enorme.

An enormous reduction.

That is a genuinely extraordinary achievement.

And it happened because of a combination of things, better delivery systems, investment in cold chains to keep vaccines refrigerated, community health workers getting into villages that were hard to reach.

It was a logistical as much as a scientific triumph.

Sí, pero después de 2016, el número empezó a subir otra vez.

Yes, but after 2016, the numbers started rising again.

En 2019, el año antes de la pandemia, hubo más de doscientos mil muertos.

In 2019, the year before the pandemic, there were more than 200,000 deaths.

Y luego llegó el COVID y todo fue peor.

Then COVID arrived and everything got worse.

Los sistemas de salud estaban ocupados con el coronavirus.

Health systems were overwhelmed.

Las campañas de vacunación pararon.

Vaccination campaigns stopped.

I want to make sure listeners understand exactly what the MMR vaccine is and how it works, because it's actually a fascinating piece of biology.

Octavio, can you walk us through the basic idea?

Bueno, la vacuna MMR contiene versiones débiles y vivas de tres virus: el sarampión, las paperas y la rubeola.

The MMR vaccine contains weakened live versions of three viruses: measles, mumps, and rubella.

Cuando el médico pone la vacuna, tu cuerpo ve estos virus débiles y aprende a combatirlos.

When you receive the vaccine, your body sees these weakened viruses and learns to fight them.

Tu sistema inmunológico crea anticuerpos.

Your immune system creates antibodies.

Si después encuentras el virus real, tu cuerpo ya sabe cómo defenderse.

If you later encounter the real virus, your body already knows how to defend itself.

And the effectiveness rate is around 97 percent after two doses.

Which, in the world of vaccines, is exceptional.

Most vaccines you'd be thrilled with 85 or 90 percent.

The MMR is about as close to bulletproof as medicine gets.

Es que noventa y siete por ciento es casi perfecto.

Ninety-seven percent is nearly perfect.

Pero hay un problema importante: necesitas dos dosis, y las dos dosis tienen que estar separadas por un mes como mínimo.

But there's an important catch: you need two doses, at least a month apart.

La primera dosis se da normalmente cuando el niño tiene entre doce y quince meses.

The first dose is typically given when a child is twelve to fifteen months old.

La segunda, entre los cuatro y los seis años.

The second between four and six years.

So there's a timing window.

And in a country like Bangladesh, where millions of children missed their vaccination appointments during the COVID years, you now have a cohort of kids, four, five, six years old, who never got either dose.

That's a tinderbox.

Exacto.

Exactly.

Y aquí hay un concepto muy importante en ciencia: la inmunidad de grupo.

And here's a very important scientific concept: herd immunity.

En inglés se llama herd immunity.

The idea is this: if most of the population is vaccinated, the virus can't travel from person to person.

La idea es esta: si la mayoría de la población está vacunada, el virus no puede viajar de persona a persona.

Even the unvaccinated few are protected because the virus can't reach them.

Los pocos que no están vacunados también están protegidos porque el virus no llega hasta ellos.

And for measles specifically, because of how insanely contagious it is, you need around 95 percent of the population vaccinated to achieve that herd immunity threshold.

That's much higher than for most diseases.

For polio it's around 80 percent.

For COVID it was debated endlessly.

Noventa y cinco por ciento es un número muy alto.

Ninety-five percent is a very high bar.

Y cuando la cobertura baja un poco, por ejemplo a noventa por ciento, el virus puede volver.

And when coverage drops even a little, to 90 percent, the virus can return.

En Bangladesh, en algunas zonas rurales, la cobertura de vacunación bajó a setenta o setenta y cinco por ciento durante la pandemia.

In Bangladesh, in some rural areas, vaccination coverage dropped to 70 or 75 percent during the pandemic.

Eso es suficiente para un brote grave.

That's enough for a serious outbreak.

I covered a measles outbreak in the Democratic Republic of Congo years ago, one of the worst in modern history.

Over six thousand children dead in a single year.

And I remember a doctor there telling me something that has never left me.

She said, measles doesn't just kill the children it infects.

It also destroys their immune memory.

Sí, esto es fascinante y muy preocupante.

Yes, this is fascinating and very alarming.

Los científicos lo llaman la amnesia inmunológica.

Scientists call it immune amnesia.

El sarampión destruye los anticuerpos que el cuerpo ya tenía contra otras enfermedades.

Measles destroys the antibodies a body already had against other diseases.

Un niño que sobrevive el sarampión puede quedar vulnerable a infecciones que antes no eran peligrosas para él.

A child who survives measles can become vulnerable to infections that previously weren't dangerous for them.

So measles essentially resets your immune system.

It can erase years of protection built up from other vaccines or previous illnesses.

Scientists at Harvard published a major study on this in 2019.

They found that measles can wipe out between 20 and 70 percent of a child's immune memory.

Veinte a setenta por ciento.

Twenty to seventy percent.

Eso es enorme.

That's enormous.

Un niño que tenía protección contra muchas enfermedades, de repente ya no tiene esa protección.

A child who had protection against many diseases suddenly loses it.

Esto explica por qué históricamente, después de un brote de sarampión, también subían los casos de otras infecciones.

This explains why historically, after a measles outbreak, other infections also increased.

El sarampión abría la puerta a otras enfermedades.

Measles was opening the door to other diseases.

Now I want to get into the vaccine hesitancy piece, because that's the other thread here, not just in Bangladesh but globally.

And this is where it gets complicated, because it's not a simple story of ignorance versus science.

La verdad es que el problema de la desconfianza en las vacunas es complejo.

The mistrust of vaccines is complex.

En algunas comunidades en Bangladesh, y también en Europa y América, la gente tiene miedo de efectos secundarios que en realidad son muy raros.

In some communities in Bangladesh and also in Europe and America, people fear side effects that are actually extremely rare.

Y hubo un estudio falso, muy famoso, que decía que la vacuna MMR causaba autismo.

And there was a famous fraudulent study that claimed the MMR vaccine caused autism.

That was Andrew Wakefield, 1998, published in The Lancet.

It was based on twelve children, twelve, and it was later revealed to be completely fabricated.

Wakefield lost his medical license.

The Lancet retracted the paper.

But the damage was extraordinary and it is still with us.

Mira, este es un ejemplo perfecto de cómo la desinformación puede matar.

This is a perfect example of how misinformation can kill.

El estudio era falso, pero muchas familias en Europa y América dejaron de vacunar a sus hijos.

The study was false, but many families in Europe and America stopped vaccinating their children.

En España también tuvimos brotes de sarampión porque la cobertura bajó en algunas ciudades.

In Spain we also had measles outbreaks because coverage dropped in some cities.

El miedo es más rápido que la ciencia.

Fear travels faster than science.

Look, I've reported from places where vaccine hesitancy is driven by genuine historical trauma.

There are communities in parts of Africa where they remember colonial medical experiments conducted without consent.

That distrust isn't irrational.

It has a history.

You can't just lecture those communities into compliance.

Tienes razón en eso.

You're right about that.

No es lo mismo el miedo al autismo en una familia de clase media en Europa que la desconfianza histórica en comunidades con malas experiencias con la medicina occidental.

The fear of autism in a European middle-class family is not the same as deep historical distrust in communities with bad experiences with Western medicine.

Pero el resultado es el mismo: niños sin vacunar.

But the result is the same: unvaccinated children.

Y el virus no hace diferencias.

And the virus doesn't distinguish.

No, you're absolutely right about that.

And this is why the WHO has listed vaccine hesitancy as one of the ten greatest threats to global health.

Not war, not climate change, specific diseases.

Vaccine hesitancy.

Because it unravels the protection that took generations to build.

Bueno, y ahora en Bangladesh, el gobierno tiene que hacer algo muy difícil.

And now in Bangladesh, the government faces something very difficult.

Tiene que llegar a millones de niños en zonas rurales, muchas veces sin buenas carreteras, y convencer a las familias de que vacunen a sus hijos.

It must reach millions of children in rural areas, often without good roads, and convince families to vaccinate.

Y tiene que hacerlo rápido porque el brote ya está activo.

And it must do this quickly because the outbreak is already active.

The emergency campaign they've launched is called a supplementary immunization activity, an SIA in public health jargon.

You essentially go door to door, village to village, targeting every child under five regardless of their vaccination history.

It's incredibly labor-intensive.

Es que esto cuesta mucho dinero y necesita muchas personas.

This costs a lot of money and requires many people.

Bangladesh no es un país rico.

Bangladesh is not a wealthy country.

Y en este momento, con la guerra en Irán y los problemas económicos globales, muchos países tienen menos dinero para la salud pública.

And right now, with the Iran war and global economic problems, many countries have less money for public health.

Los precios del petróleo subieron, los transportes son más caros, todo es más difícil.

Oil prices rose, transport is more expensive, everything is harder.

That connection is real and it's underreported.

When oil prices spike and freight costs go up, it gets more expensive to ship vaccines, to refrigerate them, to move health workers around.

The cold chain, keeping vaccines at the right temperature from factory to arm, is genuinely fragile.

La cadena de frío es fascinante como concepto.

The cold chain is a fascinating concept.

La vacuna MMR necesita estar a temperaturas muy bajas, entre dos y ocho grados.

The MMR vaccine needs to be kept between two and eight degrees.

Si la temperatura sube, la vacuna no funciona.

If the temperature rises, the vaccine stops working.

En muchas zonas remotas de Bangladesh no hay electricidad constante.

In many remote areas of Bangladesh there is no reliable electricity.

Es un problema logístico enorme.

It's an enormous logistical problem.

I mean, think about what that means in practice.

Someone has to carry a cooler full of vaccines on a motorbike across a flooded road to reach a village of three hundred people.

That person has to be trained, paid, trusted by the community.

This is not a simple operation.

A ver, y hay otra dimensión aquí.

And there's another dimension here.

Bangladesh tiene una población de unos ciento setenta millones de personas.

Bangladesh has a population of around 170 million.

Es uno de los países más densamente poblados del mundo.

It's one of the most densely populated countries in the world.

Cuando hay un brote en un lugar, se puede extender muy rápido a las ciudades.

When an outbreak starts somewhere, it can spread very quickly to cities.

Dhaka, la capital, tiene más de veinte millones de personas.

Dhaka, the capital, has more than twenty million people.

Un brote urbano sería catastrófico.

An urban outbreak would be catastrophic.

The extraordinary thing is that we are so close to eradicating measles entirely.

We've done it before with smallpox in 1980.

We're close with polio.

Measles should be next.

The tools exist.

The vaccine is cheap, effective, and has been around for sixty years.

The obstacle is not scientific.

La verdad es que tienes razón.

You're right.

La erradicación del sarampión es técnicamente posible.

Eradicating measles is technically possible.

Pero necesitamos que casi todo el mundo en el planeta esté vacunado.

But we need almost everyone on the planet vaccinated.

Un solo grupo sin vacunar, en cualquier parte del mundo, puede ser el origen de un nuevo brote.

A single unvaccinated group, anywhere in the world, can become the origin of a new outbreak.

El virus no respeta las fronteras.

The virus doesn't respect borders.

Which brings us to the final question, the uncomfortable one.

What does the Bangladesh outbreak tell us about where we are after COVID, after all the disruption, after all the misinformation?

Are we going backwards?

Mira, hay datos preocupantes.

There are worrying numbers.

Después de la pandemia, la cobertura de vacunación infantil bajó en muchos países por primera vez en treinta años.

After the pandemic, childhood vaccination coverage dropped in many countries for the first time in thirty years.

En 2021, unos veinticinco millones de niños en todo el mundo no recibieron la vacuna básica del sarampión.

In 2021, around 25 million children worldwide didn't receive the basic measles vaccine.

Es el número más alto desde 2009.

The highest number since 2009.

So in a way, Bangladesh is not an anomaly.

It is an early warning.

Those 25 million unvaccinated children are spread across dozens of countries.

Some are in sub-Saharan Africa, some in South Asia, but some are in Europe and the United States, in communities that chose not to vaccinate.

Bueno, y aquí está la ironía.

And here's the irony.

Las familias que no vacunan a sus hijos en países ricos porque tienen miedo de efectos secundarios raros están tomando una decisión diferente a las familias en Bangladesh, pero producen el mismo resultado: niños vulnerables.

Families in wealthy countries who don't vaccinate due to fear of rare side effects are making a different decision to families in Bangladesh, but producing the same result: vulnerable children.

Y cuando hay un brote, los niños pequeños y los que tienen el sistema inmunológico débil son los que mueren.

And when there's an outbreak, small children and those with weak immune systems are the ones who die.

I think what this story ultimately asks us to confront is the relationship between individual choice and collective protection.

When someone decides not to vaccinate, they're not just making a personal medical decision.

They're making a decision that affects every child around them who is too young or too sick to be vaccinated themselves.

Eso es exactamente correcto.

That is exactly right.

Y la historia de Bangladesh nos recuerda que la salud pública no es individual.

And the story of Bangladesh reminds us that public health is not individual.

Es colectiva.

It is collective.

Dependemos unos de otros.

We depend on each other.

Ciento treinta niños murieron, no porque la ciencia falló, sino porque el sistema humano alrededor de esa ciencia falló.

A hundred and thirty children died not because science failed, but because the human system around that science failed.

Eso es lo que tenemos que recordar.

That is what we have to remember.

Well said.

One hundred and thirty children who didn't have to die.

That's where I want to leave this.

Not with a policy recommendation or a lecture, just with that number and what it means.

Thanks everyone for listening to Twilingua, and Octavio, as always.

Gracias, Fletcher.

Thank you, Fletcher.

Y para todos: cuiden a sus hijos, hablen con su médico, y confíen en la ciencia.

And to everyone: take care of your children, talk to your doctor, and trust the science.

No es perfecta, pero es lo mejor que tenemos.

It's not perfect, but it's the best we have.

Hasta la próxima.

Until next time.