Seven people remained negative despite deliberate exposure to live virus.
En los pliegues del genoma humano podría encontrarse la respuesta a uno de los enigmas más persistentes de la pandemia: por qué algunas personas jamás contrajeron COVID-19, sin importar cuánto estuvieran expuestas. Un equipo de investigadores británicos, publicando sus hallazgos en Nature, expuso deliberadamente a 36 adultos no vacunados al virus original, y descubrió que siete de ellos permanecieron negativos durante todo el período de seguimiento. Lo que parecía ser suerte o disciplina podría estar, en realidad, inscrito en el código genético de cada individuo.
- Siete participantes resistieron una exposición directa y controlada al virus sin infectarse en ningún momento, desafiando las explicaciones convencionales sobre la inmunidad.
- La existencia de los llamados 'novid' generó durante años confusión y escepticismo, pues su resistencia parecía inexplicable frente a quienes se infectaban repetidamente.
- El estudio intentó replicar condiciones reales de contagio en un entorno controlado, exponiendo a adultos sanos sin inmunidad previa al virus original de la pandemia.
- Los resultados revelaron tres patrones distintos de respuesta inmune: infección con síntomas, infección asintomática, y ausencia total de infección, sugiriendo una variabilidad biológica profunda.
- Los investigadores apuntan a variaciones genéticas específicas como posible escudo natural, abriendo la puerta a una medicina personalizada basada en la resistencia innata al virus.
Durante la pandemia, un grupo de personas llamó la atención por una razón inusual: nunca se contagiaron de COVID-19. Mientras quienes los rodeaban enfermaban una y otra vez, ellos permanecían intactos. Ahora, una investigación británica publicada en Nature ofrece una posible explicación: la genética.
El estudio reclutó a 36 adultos sanos, sin vacunar y sin exposición previa al virus. Todos fueron expuestos de forma controlada a la cepa original del SARS-CoV-2, la que circuló al inicio de la pandemia. Durante al menos 28 días, los investigadores monitorearon sus respuestas inmunes mediante pruebas PCR.
Los resultados mostraron tres grupos claramente diferenciados. Seis personas dieron positivo y desarrollaron síntomas. Tres más se infectaron sin presentar ningún malestar. Pero siete participantes nunca dieron positivo, como si su cuerpo hubiera impedido que el virus se estableciera desde el principio.
Ese último grupo es el más revelador. Los investigadores creen que ciertas variaciones genéticas podrían hacer que algunas personas sean fundamentalmente menos susceptibles al virus, bloqueando su capacidad de replicarse. Si esto se confirma, el fenómeno 'novid' dejaría de ser una curiosidad para convertirse en la base de una nueva forma de entender la protección inmunológica: más personalizada, más precisa, y profundamente humana.
Somewhere in the machinery of human genetics lies an explanation for one of the pandemic's most puzzling mysteries: why some people, despite living through years of COVID-19 exposure, never caught it at all. These individuals—now called "novid"—seemed to possess an invisible shield. While their neighbors and family members cycled through infections, losing taste and smell, running fevers, these people remained untouched. A British research team decided to find out why.
The study, published in Nature and reported by Le Parisien, took a direct approach. Researchers recruited 36 healthy adults who had never been vaccinated, never been exposed to SARS-CoV-2, and had no prior immunity to speak of. They exposed all of them to the original strain of COVID-19—the version that circulated at the pandemic's beginning, before variants emerged and changed the virus's behavior. Then they watched what happened.
Of the 36 participants, 16 were monitored closely for at least 28 days. The researchers tracked their immune responses using PCR tests, building a detailed picture of how each person's body reacted—or didn't react—to the virus. The results fell into three distinct patterns. Six participants tested positive and developed symptoms that lasted more than two days. Three others tested positive but never showed any symptoms at all, their bodies fighting an invisible infection. And then there were seven: people who remained negative throughout the entire monitoring period, their bodies apparently preventing the virus from establishing itself in the first place.
That last group—the seven who never got infected despite deliberate exposure—offered the most intriguing clue. The researchers believe the answer lies in genetics. Certain genetic variations, they propose, could make a person's body fundamentally less susceptible to the virus. These variations might block the virus's ability to take hold, to replicate, to spread. It's not about behavior or luck. It's written into the code.
The implications are significant. If genetic factors truly determine who can resist COVID-19, then understanding those factors could reshape how medicine approaches viral protection. Rather than one-size-fits-all vaccines and treatments, doctors might one day identify which people carry natural resistance and tailor their approach accordingly. The "novid" phenomenon, once a curiosity, becomes a window into personalized immunity—and a reminder that human bodies are far more varied in their defenses than we typically assume.
Notable Quotes
Genetic variations could make the body less susceptible to the virus, preventing its establishment and spread— British research team (Nature study)
The Hearth Conversation Another angle on the story
So these seven people—they were actually exposed to live virus and didn't get infected at all?
Yes. That's what makes it striking. This wasn't passive avoidance. They were deliberately exposed in a controlled setting, and their bodies simply didn't allow the virus to establish itself.
And the researchers think it's purely genetic? Not something about their behavior or environment?
The study design controlled for that. Everyone was in the same conditions, exposed the same way. The difference appears to be in their DNA—specific genetic variations that make their immune systems less permissive to the virus.
What about the three who tested positive but had no symptoms? Are they also genetically protected?
Different mechanism, probably. They got infected but their bodies fought it silently. The seven who stayed negative seem to have a barrier that prevents infection from taking hold at all.
If this is genetic, does that mean some people are just born immune to COVID?
Not quite immune in the traditional sense. But yes—some people appear to carry genetic traits that make them naturally resistant. It's not about strength of will or luck. It's inheritance.
What happens next with this research?
The logical step is identifying which specific genes confer this resistance, then understanding how they work. That knowledge could eventually inform treatments or help identify who needs different protection strategies.