(2021-12-29) ZviM CDC Changes Isolation Guidelines

Zvi Mowshowitz: CDC Changes Isolation Guidelines. Previously, if you tested positive for Covid-19, you needed to isolate for ten days. Now you only need to isolate for five.

....I mean, bullshit. This is most definitely not motivated primarily by science demonstrating a distribution of transmission. If it was, the guidelines would have changed when they learned about this, rather than exactly when the guidelines otherwise needed to change

What we know is that lots of people are getting sick at once. If we forced them to isolate for ten days, there wouldn’t be anyone to staff the hospitals, man the checkout counters, drive the trucks and fly the planes. To erase any remaining doubt, The Washington Post confirms this was the motivation.

Understandable? Definitely.

But every time you say you are ‘following the science’ when you’re transparently not doing that on any level, you’re burning your credibility and the commons that much more.

Note the lack of a requirement of a negative test of any kind

Additionally, CDC is updating the recommended quarantine period for those exposed to COVID-19.

If you’re not boosted, you’re treated as unvaccinated for purposes of spread under Omicron. That makes perfect sense.

The test at five days after exposure is rather silly given Omicron’s pattern, and way too late given the quarantine requirement

Isolation relates to behavior after a confirmed infection.

Quarantine refers to the time following exposure to the virus

I do not understand this distinction. Isolation and quarantine are the same thing and using two words to make them seem like different things is confusing

Data from South Africa and the United Kingdom demonstrate that vaccine effectiveness against infection for two doses of an mRNA vaccine is approximately 35%. A COVID-19 vaccine booster dose restores vaccine effectiveness against infection to 75%.

These protection estimates are stated way too confidently. We have our guesses, and these are not insane point estimates, but they’re guesses and this is stating them as facts.

Prevention is our best option: get vaccinated, get boosted, wear a mask in public indoor settings in areas of substantial and high community transmission, and take a test before you gather.”

The continued emphasis on prevention with no attention paid to mitigation and treatment, which makes sense under a contain-the-pandemic model but not under Omicron.

My overall take is that this is a clear improvement over the old rules, but clearly not optimal

I didn’t look carefully at the chart on first review, so I didn’t notice the ‘or your symptoms are resolving’ clause here, which will get discussed below and that seems bizarre and troubling. As far as I can tell this remains unclarified

The Lack of a Required Rapid Test

Walensky said the agency decided not to require a negative test result after people had isolated for five days because the results are often inaccurateat that point in an infection

This is standard government thinking. We can’t use PCR for the sensible reason that it will stay positive long after infectiousness. We can’t use rapid tests because we don’t know how accurate they are in this particular situation, so instead we’re going to (1) not run experiments to find out, experiments remain illegal and (2) instead not run any tests at all, which is known to be about 50% accurate. I call heads.

Mina strongly disagrees with the suggestion that rapid tests wouldn’t be accurate here. That’s what they’re for and this ‘we don’t know how effective they are’ line doesn’t seem true in any relevant way.

The CDC is using the logic of probability and cost-benefit analysis. They’re saying that after 5 days the cost of isolation exceeds the benefits. The responses are wisely saying ‘you could reduce costs on the cheap by adding in a test’ but they’re also saying ‘you didn’t reduce costs to zero, therefore the policy makes no sense’ and that doesn’t engage with the actual situation

The New Guidance Is Different Than The Old Guidance

Some amount of transmission is inevitable, and we make trade-offs. That doesn’t mean that you can’t make different trade-offs with the people you care about, or adapt your actions to different situations.

People Will Ignore Your Guidance So It’s Your Fault For Not Giving Everyone Stricter Guidance

If Things Are So Bad That You Can’t Afford These Sacrifices to the Gods, Why Aren’t You Sacrificing More to the Gods?

I applaud letting private individuals make the decision as often as possible on when to do prevention and when it’s not worth doing prevention

Washington Post Roundup

Economic considerations are real considerations, hence the need to talk price, and it’s good to finally see decisions made on the basis of what’s actually at stake. But people strongly dislike it.

Also note the standard logic of ‘big business likes this therefore you know it’s bad.’

There is a longstanding problem in America where workers are effectively forced to come into work while actively sick, that has existed long before Covid-19. This is a bad norm

Thing is, the CDC’s text didn’t say that. They’re saying you still need to be symptom-free, which under normal circumstances is the definition of ‘no longer sick.’

But then the chart says ‘symptoms improving’ and this could easily give employers the green light to do exactly this, and force symptomatic people to return to work. My presumption is that this will be rare.