As far as COVID-19 goes that article refers to another news article. There’s no reference to either experimental data that suggests a threshold of exposure for COVID-19 or an explanation of the mechanics of why we should expect such a threshold.
The human immune system is constantly detecting and destroying foreign cells/viruses. People only get sick when too many of a self-replicator get into their system at the same time, and the replication outpaces the immune system response. Note that the immune response also ramps up, and eventually outpaces the replication (or the human dies).
That was all covered in my high school biology textbook.
There is substantial evidence that COVID isn’t some magical exception to the well understood immune response process.
As far as COVID-19 goes that article refers to another news article. There’s no reference to either experimental data that suggests a threshold of exposure for COVID-19 or an explanation of the mechanics of why we should expect such a threshold.
The human immune system is constantly detecting and destroying foreign cells/viruses. People only get sick when too many of a self-replicator get into their system at the same time, and the replication outpaces the immune system response. Note that the immune response also ramps up, and eventually outpaces the replication (or the human dies). That was all covered in my high school biology textbook.
There is substantial evidence that COVID isn’t some magical exception to the well understood immune response process.