Yes but then had all students mask until they took a second antigen test seven days later.
Isn’t it more likely to get false positives with PCRs though? I was actually glad they used antigen tests. They should have had the kids take one each day for first five days though instead of one and then one seven days later. Seems they could have stopped the spread faster that way.
Yes, but PCR tests are still generally more accurate, I believe. Without CDC guidance, schools are all over the place with respect to testing frequency (if they test at all). I agree that Bowdoin would have benefited from more frequent testing at least initially. They could have also done a follow-up PCR test after the initial rapid antigen test.
Well there’s no CDC plan for testing vaccinated people at all so that’s why colleges are all over the place!
PCR tests are more sensitive. They are less accurate if your goal is to catch people when they are infectious.
Good things about antigen testing:
About half of transmission happens when the infectious person does not have symptoms (either they do not have symptoms yet, or they will never have symptoms). If you use antigen tests, people who are infectious will test positive, regardless of symptoms, and can be removed from contact with others until they test negative with further antigen tests.
Drawbacks to antigen testing:
Some people who are infected, but not yet infectious, will test negative. However, you can test close contacts every day with antigen testing, and if they become positive, they are infectious and should be separated from others.
Good things about PCR:
For unvaccinated or otherwise high-risk people, it is good to know ASAP if they are infected so they can get monoclonals/treatment. They will likely test positive on PCR before they are infectious (once infectious, they will test positive on both tests).
Drawbacks with PCR:
A person will test positive on PCR after their body has contained the virus and they are no longer infectious. So, if you use PCR, you will be quarantining people who were infectious days or even a week ago.
Also, we do not know the accuracy of PCR in vaccinated people because it tests for fragments of RNA, which could be present after the immune system beats the virus. Bits of viral RNA does not equal an infectious person.
Hope that helps. In highly vaccinated environments, I don’t think asymptomatic vaccinated people who are not high risk should be tested. Symptomatic people should be tested so that they can isolate for the rest of their infectious window, to protect others. To determine the infectious period, antigen tests should be used daily. It is not helpful to know that the person has been infected—only whether they are contagious.
I think antigen tests have a pretty high rate of false negatives. Amherst gave students both rapid antigen tests and PCR tests upon arrival; out of four students at Amherst College who tested positive upon arrival, two of them tested negative on the initial antigen tests.
Yes, this should be the goal of testing for public health (as opposed to the goal of testing for individual diagnosis).
Students who tested positive on PCR but negative on antigen did not have enough active virus in their bodies to be contagious.
Two options:
They were not contagious yet, but would likely become contagious (and test positive on antigen) in the next two days.
They had Covid, but their body fought it off and they no longer have active virus present.
People test positive on PCR for longer after the infectious period than before it. Therefore, option 2 is more likely, and kids who are not infectious and will not become infectious are quarantined unnecessarily.
Antigen tests detect a protein the virus makes when it is “alive” and actively infecting cells.
PCR does not test for active virus. It detects any fragments of RNA, whether “dead or alive”.
In addition to the above disadvantages for PCR tests for public health purposes (versus individual medical decisions), PCR tests are often slow to get results back. This delay can mean unnecessary quarantine while waiting for results, or being an unknown positive before results are seen.
This is all pretty interesting. What I hear, standing back as far as I can, is the sort of muscular effort you usually ascribe to brides coming up on their wedding days who know deep down that this isn’t a great idea, but everyone’s RVSP’d and bought tickets and bridesmaids’ gear, the caterer’s been paid, the dress is perfect, the shower’s been had and the bachelorette party’s in two days, the guy’s still fine most of the time, and it can all be written off to nerves if she squints a bit.
I think we’re mostly still coming around to the idea that we’re going to be living with this thing for a long time. We don’t yet know what the longterm effects are, but we do know that a significant number of young and old people who get this have trouble recovering, that vaccination so far generally reduces acute illness and death but is not a guarantee of short illness, and some few are flat-out disabled. It is, in other words, a societally blighting pandemic virus, and the science on it and its mutation is still in its infancy.
So far, though, when it comes to how we’re living, I’m not yet seeing serious moves to adaptation. The virus seems to me to be doing a much better job of that than we are. It’s as though we haven’t yet accepted that “endemic” and “blighting” coexist – we’re not used to that here anymore. So far what I’m seeing is a binary thing: we’re living as (previously) normal or we’re in a sort of lockdown. Kids are in class with naked-face lecturers and living happily in dorms and having a pre-covid social life or there are temporary dramatic hassles that we expect must go away, soonish, because accepting anything else is still seen as a sort of capitulation.
I think this attitude will have to go away, and my guess is that the kids will lead there, as they’re doing in so many other ways, given older people’s inability to work together. I think that when we look back in 20 years, this will have been a massive shove that’s just one important factor in the end of the American 20th-c campus experience, outside elite institutions and their clientele – and their experience of course isn’t really American 20th-c.; it goes back a long way. I don’t know what “living with covid” will look like, in higher ed or in the broader society – I don’t think that people have brought their minds round yet to anything as long-term as, say, the consideration of STDs has become since AIDS, or the way city families lived in summer before the polio vaccine, or the way people live in areas where malaria and TB are endemic. But I do think this binary “it’s nothing” vs “we’re suffering through lockdown” will wind up changing to a way of actually living with this that includes the “yes, it’s quite serious, and here’s how we accommodate that” part all through.
A girl on my daughter’s hall has already gone home with Covid. The rest – this is an honors dorm – have masked up outside their rooms. No one told them to do that and it isn’t required. Daughter said she wasn’t surprised about the girl; she’d seen the girl going out to the bars. I can see this generation handling this in ways quite different from older ones, with a much readier and somehow oldfashioned approach to social negotiation and coercion: I can see pressure being applied to kids who do go out and expose themselves in the form of “nobody’s going to tell you what to do but you’re making things dangerous for everyone else and we agree that that isn’t fair to people who are trying to be careful.” Part and parcel of their more social sense of life.
Of course, those college kids are able to do so because they are not required to earn a living, support and raise dependents, or do any of the myriad other responsibilities actual adults have. Generally, their housing, food and medical care are all provided to them, and their only concern is attending class. That is not the case for most adults, who must manage risk differently.
If the kids are planning to lead the rest of us here in how to live with Covid, perhaps they might start to hit up fewer bars and parties and head to the vaccine clinic. Throughout this pandemic, there has been significant asymptomatic and mild symptomatic spread due to young adult socializing w/o masks and in violation of social distancing recommendations or orders. They also remain at a lower rate of vaccination than their elders. Earlier on they were referring to Covid as “Boomer Remover.” We all love our young people but they are responding to this pandemic in an age appropriate way - it doesn’t affect them as much, so they don’t worry as much about it.
seriously? There are a ton of adults doing the same - dining out or going to bars. It’s not just college kids. Honestly, I’m fine with people going out and about if they are vaccinated. It’s the unvaccinated crowd that should be masking and distancing or, better yet, getting a vaccine. Maybe big parties at colleges should be asking kids to show vaccine cards if they are on a campus without 99% of the kids vaccinated but our politics in many states make that a fantasy.
Normalization would be necessary simply because the two countries are of very different size. In terms of the UK, the graph for positivity (PCR testing) generally tracks the path of the virus through at least 8/1.
If a policy of widespread daily testing works, we’ll see it in the number of reported infections. Right now, the two countries are still reporting similar (normalized) seven-day averages. The total number of genuine infections can only be estimated, similar to what the CDC is doing.
https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html
Perhaps the UK should have a smaller variance around it’s own estimate due to more widespread regular testing.
Yes, but only if the “tally” you are normalizing was obtained by comparable means/methods.
That’s the problem with raw data vs. statistics: Yes, one can give those raw-data tallies the same column labels and gather them in large tables (and even visualize those tables in charts) - but an informed reader will know that this in no way implies that those tabularized figures can also be used in comparisons.
If one country does test large segments of the population regardless of health status,
while in another county, sporadic testing is decided on a whim by each individual, e.g.
then those two countries’ counts don’t represent the same information.
Dividing two entirely different numbers (even if labeled the same) by population will yield two arithmetically “undisputable” quotients that can be looked at separately, but they cannot be used for comparison between the two.
You would get equally arithmetically-valid results by dividing them by the number of burger-restaurants in each country and then marvel at whatever similarity or dissimilarity you “discover” (even if published on the Restaurant-industry web site).
Spoke to my counterpart in Germany yesterday, who had just attended a large “4 birthdays” outdoor celebration in the countryside. We were talking about the vaccination status among the 100+ attendees of all generations.
Interestingly, his observation had been, that the 55+ had been eager to get vaccinated due to high risk, but the below-30 friend circles had been even more proactive to hunt down appointments: They didn’t want to be shunned from clubs, discos and other public venues.
It was actually the “middle-aged” population that had the most “slackers” who just couldn’t be bothered yet. They were content having settled down at home or with friends, and not too worried yet because of their relative youth.
Don’t know if there’s data about vaccine acceptance by age range within the initial x months after availability for that age range, but intuition might be proven wrong.
When my Junior daughter moved into her NYC apartment last fall, she and her four room mates decided that everyone had to get a Covid test the day before moving in and made up their own move-in schedule, making sure that their different families would not be in the apartment on the same day.
As you said: Nobody told them to.
They even had a zoom meeting before, hashing out ahead of time how they would handle, if one were to need to isolate!
Needless to say I was both impressed (and proud) how mature they acted. (I was tempted to saw “grown-up”, but that might almost be an insult - given how many “grown-ups” act!)
In the US, the younger you are, the more likely you are unvaccinated:
https://data.cdc.gov/Vaccinations/COVID-19-Vaccination-and-Case-Trends-by-Age-Group-/gxj9-t96f
Here in the US the trends are more straightforward. In my state, for instance, which has had widespread vaccine availability since March 30, the percentage of fully vaccinated increases by age group: 12-15 < 16-17 < 18-49 < 50-64 < 65+. This trend holds by age group within each ethnic/racial population as well (NB: the age ranges are slightly different: 12-18 < 19-44 < 45-64 < 65+). Bars and clubs here haven’t implemented a vaccine requirement, so perhaps that explains it. I suspect that’s pretty typical throughout most of the US. It’s possible that the 19-31’s are quite eager to hunt down vaccines while the 32-44’s are slacking off, thus dragging down the overall age group. But I doubt it; the overall US data doesn’t show that:
Haven’t seen Germany’s data by age group but guessing that if there are indeed middle-aged “slackers” then you should see that in their data by now. Both the below-30’s and the middle-agers are in that 16-60 yo group that should have had access to the vaccine for the past few months.
makes sense given the relative likelihood of hospitalization/death based on age…many healthy, young adults are not overly worried about Covid whereas the elderly are rightly very concerned
You are probably making the “perfect” the enemy of the “good” (or at least the “useful”). There are also differences in how various localities report the data. FL has different standards than NY. And yet the CDC and other health experts use normalized data to understand incidence rates across the country.
These are positive cases reported. If testing policies between two countries are in contrast to one another, we’ll start to see that in the data . . . because the more aggressive one will result in lower normalized cases (assuming, of course, that such a policy actually works). Let’s watch and find out.