Comment by cout | Hacker News Reader

Comment by cout | Hacker News Reader

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Yes, that's the confusing bit.

In February, the CDC said that those with the vaccine can have asymptomatic infections (https://web.archive.org/web/20210209162120/https://www.cdc.g...). The NY Times used the term "silent spreaders".

Then in March the CDC's guidance was to continue wearing a mask after vaccination, except in situations where transmission risk was minimal (such as when everyone present has been vaccinated). They said we should do this while we're still learning about how vaccines affect the spread of the virus (https://web.archive.org/web/20210308164227/https://www.cdc.g...).

Now the CDC is saying fully vaccinated individuals do not need to wear a mask (https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vac...), but no reason has been given for the change on that page. Were they wrong on asymptomatic infections in fully vaccinated individuals, or has the risk of spread simply been lowered because of the number of individuals who have received a vaccine?

Without knowing the reason behind the change in guidance (I'm sure there is one), I find it easy to be cynical and distrusting.

The changes can be explained by two simple factors, without the need for some grand nefarious conspiracy:

* The CDC's default position is caution * We know more now than we did in the past

In February, we realized vaccinated people could still get asymptomatic infections. Out of an abundance of caution, the CDC recommends vaccinated people keep wearing masks because the vast majority of the population isn't vaccinated.

As evidence accumulates in the intermediate time, we realize that vaccines also lower the percentage of people with asymptomatic Covid-19 [1]

With even more evidence, we realize vaccinated people overwhelmingly avoid hospitalization, which is the real issue we are trying to avoid [2]

With those two pieces of information, the CDC can now change their recommendation. Nothing nefarious going on, nothing 'unknowable' to anyone paying attention.

The problem is when people who are already predisposed to distrust the CDC - most likely due to their media diet - and put 0 effort in understanding the changing landscape see the CDC change the recommendation and assume it must be 'something political'. Those of us who were paying attention weren't that surprised about the announcement.

[1] https://www.cdc.gov/coronavirus/2019-ncov/science/science-br...

[2] https://www.cdc.gov/media/releases/2021/p0428-vaccinated-adu...

I don't have a source for you, but my understanding is that the main reason for the change is that very recent studies have shown that people with vaccines and asymptomatic "breakthrough" infections carry a much lower viral load + viral shedding than previously thought. So even those vaccinated people who may have an asymptomatic infection are really at an extremely minimal chance to spread it to anyone else; they just aren't shedding enough virus particles to make the risk high.

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