Protection only works while you're taking it
En un momento en que la prevención del VIH exige tanto rigor científico como sensibilidad humana, México ha dado un paso significativo: su autoridad nacional de salud lanza una estrategia que combina medicación antirretroviral previa a la exposición con el uso consistente del condón, reconociendo que ninguna herramienta única puede proteger a todos por igual. CENSIDA, el organismo rector en la materia, apuesta por la redundancia como principio rector, construyendo capas de defensa donde antes había una sola. Es una admisión honesta de que la biología y el comportamiento humano son imperfectos, y que la salud pública debe diseñarse para ese mundo real, no para el ideal.
- México enfrenta una brecha persistente en la prevención del VIH: las intervenciones aisladas no alcanzan a quienes más las necesitan, y el virus sigue encontrando caminos donde la protección es incompleta.
- CENSIDA responde con una estrategia de doble protección que combina la PrEP —medicación antirretroviral con más del 95% de eficacia— con el uso del condón, atacando simultáneamente la transmisión del VIH y otras infecciones de transmisión sexual.
- La PrEP se ofrece de forma gratuita en dos modalidades: píldora diaria para quienes enfrentan riesgo continuo, y dosificación por evento para situaciones de exposición episódica, ampliando así el alcance a distintos perfiles de vida.
- El éxito de la estrategia depende de algo más difícil que la disponibilidad del medicamento: la adherencia sostenida y el cambio de comportamiento en poblaciones que enfrentan barreras sociales, económicas y culturales.
- La iniciativa se posiciona como un modelo de prevención adaptable, que abandona la lógica de la solución única y construye resiliencia ante los fallos inevitables del mundo real.
La autoridad mexicana de prevención del VIH ha puesto en marcha una estrategia que combina dos herramientas complementarias: la profilaxis previa a la exposición —conocida como PrEP— y el uso consistente del condón. El director general de CENSIDA, Juan Luis Mosqueda Gómez, ha subrayado que esta "doble protección" actúa en dos frentes distintos: la medicación bloquea el virus desde dentro del organismo si este logra ingresar, mientras que el condón impide físicamente tanto el VIH como otras infecciones de transmisión sexual.
La PrEP no es una vacuna. Ofrece una protección superior al 95% únicamente mientras se toma de forma correcta; al suspenderla, esa protección desaparece. Para adaptarse a distintas realidades de vida, México la ofrece gratuitamente en dos formatos: una píldora diaria para quienes enfrentan riesgo continuo, y una pauta de cuatro comprimidos tomados antes y después de una situación de riesgo puntual, pensada para quienes la exposición es ocasional.
CENSIDA ha definido criterios epidemiológicos —no morales— para identificar a quienes más se beneficiarían de la PrEP: personas con parejas seropositivas sin tratamiento, uso inconsistente del condón, múltiples parejas sexuales o infecciones de transmisión sexual recientes.
La verdadera apuesta de esta estrategia es la redundancia. Las personas olvidan pastillas. Los condones fallan. Las circunstancias cambian. Al combinar ambos métodos, la estrategia reconoce que el mundo real es más complejo que cualquier ensayo clínico, y que una prevención eficaz debe estar diseñada precisamente para esa imperfección.
Mexico's national HIV prevention authority has rolled out a two-pronged defense against the virus: medication taken before exposure, paired with the oldest and most reliable barrier method available. The strategy, launched by CENSIDA—the National Center for HIV/AIDS and Hepatitis Prevention and Control—represents a deliberate shift away from betting everything on a single intervention. Instead, it layers protection, acknowledging that no single tool works perfectly for everyone, and that the virus finds its way through gaps in any single defense.
The approach centers on what officials call "double protection." Juan Luis Mosqueda Gómez, CENSIDA's director general, has emphasized that the most effective way to prevent transmission is to combine antiretroviral medication taken before potential exposure—known as PrEP, or pre-exposure prophylaxis—with consistent condom use during all sexual contact. The logic is straightforward: the medication works inside the body to stop the virus if it enters; the condom creates a physical barrier that prevents not only HIV but also other sexually transmitted infections from crossing in the first place. Together, they address two separate pathways of infection.
PrEP itself is a relatively recent tool in the prevention arsenal. It consists of antiretroviral drugs taken by people who do not have HIV to prevent them from acquiring it. When taken as prescribed, the medication achieves a protection rate exceeding 95 percent. But this figure carries an important caveat: it only works while someone is actually taking it. PrEP is not a vaccine. It offers no lasting immunity. Stop taking it, and the protection evaporates. In Mexico, the government provides PrEP at no cost, and offers it in two distinct forms to match different patterns of risk. The first is a daily oral pill, designed for people whose exposure to the virus is ongoing and unpredictable. The second is event-based dosing—four tablets total, taken before and after a specific sexual encounter or isolated risk situation—for those whose exposure is episodic rather than continuous.
CENSIDA has identified several markers that indicate who should be considered for PrEP. These include having a sexual partner with HIV who is not under medical care, using condoms inconsistently or not at all, having multiple sexual partners, or having recently contracted another sexually transmitted infection. The list is not moralistic; it is epidemiological. These are the circumstances in which the virus is most likely to find a foothold.
The strategy represents a recognition that prevention is not a one-size-fits-all proposition. Different people face different risks, and different tools work better for different situations. By offering both daily and event-based PrEP, CENSIDA is acknowledging that some people can commit to taking a pill every day, while others cannot or will not. By pairing medication with condoms, the strategy avoids the trap of assuming that any single intervention will be used perfectly every time. The real world is messier than clinical trials. People forget pills. Condoms break. Relationships change. The combination approach builds in redundancy—if one method fails, the other may still hold.
Citações Notáveis
Effective prevention requires combining antiretroviral medication with consistent condom use in all sexual relations— Juan Luis Mosqueda Gómez, CENSIDA director general
A Conversa do Hearth Outra perspectiva sobre a história
Why combine PrEP with condoms if PrEP alone is 95 percent effective?
Because that 95 percent assumes perfect use—taking the pill every single day, exactly as prescribed. Real life is different. People miss doses. And even if PrEP works perfectly against HIV, it does nothing against gonorrhea or chlamydia or syphilis. The condom handles both.
So this is really about acknowledging that people aren't perfect?
Exactly. And it's not judgmental about it. CENSIDA is saying: we know you're human. We're going to give you tools that work even when you're not perfect.
Why offer two different versions of PrEP—daily and event-based?
Because the risk patterns are different. Someone in a long-term relationship with an HIV-positive partner faces constant exposure. Someone who has occasional high-risk encounters doesn't. Forcing everyone into the same regimen wastes resources and sets people up to fail.
Is there a catch to free PrEP in Mexico?
The catch is adherence. You have to actually take it. And you have to keep taking it. The moment you stop, you lose protection. It's not like a vaccine where you get two shots and you're done for years.
Who decides if someone qualifies for PrEP?
CENSIDA has criteria—inconsistent condom use, multiple partners, recent STIs, or a partner with untreated HIV. But the real question is whether people at risk actually know these criteria exist and can access the medication. That's where the strategy lives or dies.