LogFAQs > #944170649

Clench281 posted...

This is actually disingenuous. While a single virion CAN infect a person, there is a well-documented relationship between the number of virions one is exposed to, and the resulting severity of disease (or whether or not it results in disease at all). Each disease has its own "infectious dose" represented as the median number of bacteria or virions required to infect a person.

Masks don't reduce your virion emissions to zero. But they necessarily will reduce the number of virions expelled away from your immediate location, and/or reduce the distance they travel.

Also that. Lower pathogen load=lower chance of infection/less severe infection. This is pretty intuitive: the body has a much easier time mounting an immune response against a smaller number of pathogens than a larger number. Some percentage of the virions that do manage to enter your body are also just going to fail to reproduce spontaneously, and having a smaller initial population exponentially increases the likelihood that the whole population will end up suffering such a fate.

You can end up with an infection from a single virus particle, but it's nonetheless true that being exposed to fewer virions is a good thing.

Clench281 posted...

The main takeaway seems to be that governmental intervention policies are a poor predictor of changes in transmission rate in the epidemic.

To that I say no crap. Many people self-impose interventions like social distancing and mask wearing regardless of the law. Many businesses have done the same, encouraging employees to work from home when possible even if not legally required. At the same time, many people refuse to adhere to policies that have been enacted. Both of these factors reduce the association between policy and transmission rates

Besides, the whole premise of modeling infection rates ~ government intervention in this manner is a bit dubious, given that they're interdependent variables. You don't just have regions that stay '100% open' or '100% shut down,' they're changing over time. That's further going to weaken the association.

Roughly my thoughts. I do have to question some of the premises presented, like there not being an increase in deaths per day after a certain point (there's a clear upward trend starting in late July for the US, albeit less of one than the initial spike) and not taking into account variations in countries' deaths per day (it's looking just at how much that figure changes), but the bottom line is that mandates tend to come into effect later than unofficial policies and recommendations that people have already been doing voluntarily. The CDC recommended masks long before any counties started passing mandates for using them, and a sizable number of people listened.

Broadly, mandates are passed to stomp out the last vestiges of resistance, not as a first line of public health. They exist to force everyone to follow what the proactive people are already doing, so naturally they're going to lag behind the effects of proactive people doing the things they mandate. That doesn't mean they shouldn't be happening or that the things they suggest are useless, it just means they aren't making all the difference.

Really, think about it: Does it really make sense to suggest that having the entire population try to minimize contact with other people wouldn't have a significant negative impact on the transmission of an airborne virus? That placing any sort of barrier in front of your face that limits the speed at which air (and, by extension, aerosols) leaves your mouth/nose wouldn't restrict transmission to some extent or another? The magnitude of these changes is, of course, going to have to be determined empirically and/or with far more complex modelling than any of us are capable of doing off-hand, but just looking at it intuitively, ask yourself what assumptions about the virus would have to be untrue for these control efforts to truly be as meaningless as you seem to want them to be. I'll give you a hint: "It's a virus" would be one of them.

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