It is simply too early to make definitive claims
En medio de uno de sus peores brotes de dengue en décadas, Argentina ha decidido mantener la vacunación como una opción voluntaria, no una obligación. Con 129 muertes y más de 180.000 casos confirmados en la temporada 2023-2024, el gobierno argumenta que la falta de consenso científico internacional y la ausencia de autorización de la FDA para la vacuna Qdenga impiden dar ese paso. Es una tensión tan antigua como la salud pública misma: la prudencia institucional frente a la urgencia humana, el rigor de la evidencia frente al peso de los muertos.
- Argentina enfrenta su peor temporada de dengue en memoria reciente, con 129 fallecidos, 398 casos graves y más de 180.000 contagios confirmados en lo que va de la temporada.
- A pesar de la magnitud del brote, el Ministerio de Salud rechazó incorporar la vacuna Qdenga al calendario obligatorio, citando estudios preliminares y la falta de aval de la FDA y organismos internacionales.
- Brasil, país vecino con el mismo brote, tomó el camino opuesto: ya tiene 9 millones de dosis aseguradas para 2025 y espera vacunar a 3,2 millones de personas antes de fin de año.
- Especialistas como el infectólogo Eduardo López consideran que Qdenga es segura y eficaz, pero advierten que su corta trayectoria impide afirmar con certeza cuánto dura su protección a largo plazo.
- La vacuna está disponible para quien la quiera —aprobada por Anmat desde abril de 2023 para mayores de cuatro años— pero la pregunta de si debe ser exigida permanece sin respuesta oficial.
El Ministerio de Salud de Argentina anunció esta semana que la vacunación contra el dengue no será obligatoria, en medio de una temporada que ya acumula 129 muertes y más de 180.000 casos confirmados. Las autoridades reconocen la gravedad del brote, pero sostienen que aún no existe el consenso necesario —ni con especialistas en enfermedades infecciosas ni con organismos internacionales— para incorporar la vacuna Qdenga al calendario nacional.
Qdenga recibió aprobación de seguridad por parte de Anmat en abril de 2023, pero el gobierno subraya que eso no equivale a avalar su uso obligatorio. Un argumento central es que la FDA estadounidense no ha autorizado esta vacuna —sí lo ha hecho con Dengvaxia, bajo condiciones muy específicas— y que los estudios sobre su efectividad en distintos grupos etarios y regiones endémicas todavía están en curso.
El contraste con Brasil es llamativo. El país vecino ya tiene aseguradas 9 millones de dosis de Qdenga para 2025 y avanza hacia vacunar a 3,2 millones de personas este año. Mientras tanto, en Argentina, de los más de 180.000 casos registrados, 398 fueron clasificados como dengue grave.
El infectólogo y pediatra Eduardo López describe la vacuna como eficaz y segura según los ensayos clínicos disponibles. Explica que Qdenga es cuadrivalente —usa el serotipo 2 como vector e incorpora material genético de los serotipos 1, 3 y 4—, lo que resulta especialmente relevante en Argentina, donde el tipo 2 representa cerca del 60% de los casos y suele provocar cuadros más severos. La vacuna requiere dos dosis separadas por tres meses, y su protección se estima en cuatro años y medio.
Lo que aún no puede afirmarse, advierte López, es su efectividad a largo plazo: Qdenga es demasiado nueva para saberlo. Esa incertidumbre, en medio de un brote que no da tregua, es precisamente el nudo que el gobierno argentino dice no estar listo para desatar.
Argentina's Health Ministry announced this week that it would not make dengue vaccination mandatory, even as the country grapples with one of its worst outbreaks in recent memory. The 2023-2024 health season has brought 129 deaths and more than 180,000 confirmed cases across the nation, according to epidemiological bulletins released by the ministry itself. Yet despite these numbers, officials say the moment is not right to require vaccination.
The vaccine in question, Qdenga, received safety approval from Argentina's drug regulator, Anmat, in April 2023. But the ministry's statement makes clear that approval for safety is not the same as approval for mandatory use. Neither the previous government nor the current one, the statement notes, has achieved consensus with infectious disease specialists and international health bodies on whether the vaccine should be added to the national vaccination schedule. The ministry also points out that the vaccine remains in preliminary studies, with its effectiveness still being evaluated across different age groups and in regions where dengue is endemic.
The U.S. Food and Drug Administration has not authorized Qdenga, which the Argentine ministry emphasizes in its reasoning. Officials argue that without such validation, the vaccine cannot yet be considered a proven tool for controlling disease transmission during an active outbreak. This position aligns with recent assessments from the Pan American Health Organization, which reported that dengue cases across the Americas have tripled compared to the same period last year. The FDA has approved a different dengue vaccine, Dengvaxia, but only for people aged 6 to 16 who have had a confirmed prior dengue infection and live in endemic areas.
Brazil presents a starkly different picture. There, Qdenga has been approved and the government is actively working to expand production. Officials expect to vaccinate approximately 3.2 million people by the end of this year, with 9 million doses already secured for 2025. The contrast underscores how differently neighboring countries are approaching the same outbreak.
In Argentina, of the 180,529 cases recorded so far this season, 398 have been classified as severe dengue. To understand the vaccine better, CNN spoke with Eduardo López, a pediatrician and infectious disease specialist. He describes Qdenga as both effective and safe based on field studies and clinical trials. The vaccine is Japanese-made and requires two doses: the first dose provides some immune response but does not offer adequate protection on its own. A second dose, given three months later, is necessary for full coverage. López explains that the vaccine uses dengue type 2 as its vector and incorporates genetic material from dengue types 1, 3, and 4, making it quadrivalent. This matters in Argentina because type 2 dengue accounts for about 60 percent of cases and tends to cause more severe illness with more pronounced symptoms.
According to official studies, Anmat has approved the vaccine for people as young as four years old and of any age beyond that. López notes that anyone who wants vaccination can receive it—the question is whether it will be required. He also points out that the vaccine provides protection for four and a half years. What remains unproven, he emphasizes, is long-term effectiveness. Because Qdenga is new, it is simply too early to make definitive claims about how well it prevents infection over time. The ministry's caution reflects this uncertainty, even as the death toll continues to climb.
Citações Notáveis
The vaccine is effective and safe based on field studies and clinical trials, but it is too early to make definitive claims about long-term effectiveness.— Dr. Eduardo López, pediatrician and infectious disease specialist
A Conversa do Hearth Outra perspectiva sobre a história
Why would a country facing 129 deaths reject a vaccine that experts say is safe?
Because safety and effectiveness are different questions. Argentina approved the vaccine as safe, but they're saying we don't yet know if it actually stops people from getting dengue—especially at scale, during an outbreak.
But Brazil is vaccinating millions. Are they taking a bigger risk?
Not necessarily. Brazil decided the risk of waiting for perfect data was higher than the risk of using a vaccine that's proven safe. Argentina chose the opposite calculation.
What does the specialist López actually think should happen?
He thinks the vaccine works and is safe. But he's honest that it's new—we don't have years of data yet. He's not saying don't use it. He's saying we're still learning.
So people in Argentina who want the vaccine can get it?
Yes, if they can find it and afford it. It's not banned. It's just not mandatory, and it's not part of the public health strategy.
What changes this calculation?
Time, mostly. More data on how long protection lasts, how well it works in different populations, whether the FDA eventually approves it. Right now, Argentina is betting that mosquito control and case management are enough.