|
Agreed - more data is better.
While we’re conditionalizing on various data points, I found this preprint interesting. It’s a longitudinal study that suggests that though vaccinated people
who are infected with covid can spread the disease, they do so for a more limited time and in more limited ways than unvaccinated infected people. This suggests that, on average, it is more difficult for a vaccinated infected person to spread covid than for
an unvaccinated infected person, even though they can do it and even though
some infected vaccinated people might be very infectious.
If this is true, then we need to treat with care our claims about vaccinated people spreading covid. They do not do so as easily as the unvaccinated in
two ways: not only are they much less likely to have covid, but even if they do, they are not as likely to be as infectious as an unvaccinated counterpart. That’s great news in light of the US CDC’s botched messaging about vaccinated people
spreading covid. And it should also be factored in to our risk assessments.
Dai
***************
Dr. Dai Heide
Senior Lecturer
Dept. of Philosophy
Simon Fraser University
Hi Dai,
I didn't know the numbers after the Provincetown outbreak were so much more benign. Thanks! I'll shift my estimate of the risks downward a bit. But not all the way because the other data counts too,
including the vulnerable people who were not part of the petri dish but whom the vaccinated people might have infected next.
I used Iceland as the case study precisely because their outbreak started with young people in nightclubs and then spread through a larger population (300k for Iceland, maybe about 60k SFU community
counting family members). Unlike with Provincetown, we have some idea of where the outbreak ended and thus what the total cost was. As of right now, the Iceland outbreak has caused a total of about
4k cases, the majority of which were vaccinated, 73 hospitalizations, 3 deaths. (It's possible that these come from more than a single source of course.)
As I said in the other email, if it starts with an outbreak here it should count no matter where it goes next. In particular, of course unvaccinated members of our community would bear the brunt of
it, but why shouldn't they count as people we need to protect?
Hence, vax mandate, and masks/testing in the interim until we get the community spread back under control. I definitely agree that our classrooms will be safer than nightclubs but see my earlier email
about the Marin county case where 1 teacher infected I think 18 (masked, distanced) students.
Anyway, you're right it shouldn't be just a back of one napkin calculation. It should be the backs of many napkins. That's why we're having this discussion, and I would love to be proven
wrong in my pessimism.
Lucas
From: Dai Heide
Sent: September 3, 2021 6:16:57 PM
To: Lucas Herrenbrueck
Cc: Igor Herbut; Bernard Crespi; James Fleming;
academic-discussion@sfu.ca
Subject: Re: Estimate of % students vaccinated. Message from the President: Return to Campus planning updates
Lucas,
The scenario you suggest (20-50 hospitalizations and 1-5 deaths) far exceeds what occurred in the Provincetown outbreak. By all counts, the vast majority of the 60,000+ attendees were vaccinated. Moreover, they were congregating in environments
that are extremely conducive to the spread of viruses: very old, poorly ventilated structures in loud environments that required people to raise their voices or even shout. (Dive bars, in other words.) There have also been numerous reports of after parties
in private residences. The party lasted for several days.
So this was a Petri dish, a perfect atmosphere for spreading a contagion. According to the CDC, 469 attendees were diagnosed with Covid. Five were hospitalized and there
were no deaths. Reporting in the news media suggests that many of those diagnosed with Covid were unaware that they had been infected and received a test only while seeking treatment for another medical issue or because they were notified that they were in
close contact with someone who had tested positive.
Surely classrooms and cafeterias are dangerous, but I find it hard to believe they are as dangerous as loud bars. So it’s not so easy for me to envision the “case study” you outline when a very recent actual case study of a Delta outbreak led
to significantly better results.
I would prefer no outbreaks. But some of what we can learn about the risks of covid in groups needn’t be worked out on the back of a napkin. We can look at what has actually occurred.
Perhaps the real lesson of Provincetown is this: if you create an environment that is extremely conducive to viral spread, vaccinated people will become infected, and sometimes by other vaccinated people, but the vast majority
of them (in this instance 98.9%) will avoid an outcome as serious as hospitalization.
Dai
***************
Dr. Dai Heide
Senior Lecturer
Dept. of Philosophy
Simon Fraser University
Hi everyone,
James: I wonder if you are aware of the evidence that Delta can spread, quite easily, even in
a 75% vaccinated population?
Igor: thanks for the calculation! I concur with it, but also want to remind that we'll have incoming international students who won't be all vaccinated, at least not until November.
But let's be positive and say 75% are fully vaccinated for the next few months - incidentally, that's exactly what we assumed in our August
4 Open Letter. Delta says that's not enough, not nearly. Basic epidemiology: the disease the spreads until R0*[1-{fraction immune}*{efficacy of immunity}] < 1.
Based on the current state of the science, R0=5-8 and vaccine efficacy against infection is 50-80% (depending on which vaccine and how long ago it was taken). Let's be optimistic again
and set R0=6 and VE=.8. This means Rt = 6*[1-75%*80%] = 2.4, which is identical to the original strain from 2019!
So without additional measures like masking, distancing, rapid testing and effective contact tracing, outbreaks would spread just as quickly as in January-March 2020.
Now, given high vaccine efficacy against serious illness and death, this is not an "everyone dies" kind of situation. But it easy to
see how a single superspreading event - let's say a pre-symptomatic instructor who made the personal choice not to wear a mask, or a sneezy student who didn't want to miss a midterm - could result in 1000 follow up cases, out of which:
- 800 will 'only' have to isolate for 2 weeks
- 150 will 'only' develop a currently untreatable chronic condition which causes severe headaches, fatigue, and loss of brain function
- 20-50 will be hospitalized
- 1-5 will die.
These numbers are guesses, but they're consistent with current data on likely Covid outcomes in a youthful and highly vaccinated population. If there is spread to unvaccinated children and elderly relatives,
we would expect worse.
If we get to 100% vaccinated on campus, then the numbers above become less dire - maybe cut them all in half. (Given Delta's high R0 and breakthrough rate, even 100% vaccination does not confer mathematical
herd immunity.)
Just to be clear, is this what we mean when we say "we need to learn to live with Covid"?
For me, as I've said before in this forum, it means "let's still keep our masks on until Covid spread in BC is at most a tenth of what it is now, and do whatever it takes - mandating, testing, ventilating - to get it down much further".
Lucas
From: Igor Herbut <igor_herbut@sfu.ca>
Sent: September 2, 2021 6:13:39 PM
To: Bernard Crespi; James Fleming
Cc: academic-discussion@sfu.ca
Subject: Re: Estimate of % students vaccinated. Message from the President: Return to Campus planning updates
Bernard,
We do have some idea: according to the last bc cdc report at
which ends with the week August 13 - August 21, in the age cohort 20-29 80 % (65%) were partially (fully) vaccinated. I would guess that the SFU students are more likely to be vaccinated than the
general BC population of the same age. Adding twelve more days that passed since August 21st during which the percentages could only increase would suggest that the conservative lower bound on the percentage of fully vaccinated SFU students is around 70%.
Cheers,
Igor Herbut (physics)
From: Bernard Crespi <bernard_crespi@sfu.ca>
Sent: Thursday, September 2, 2021 5:01 PM
To: James Fleming
Cc: academic-discussion@sfu.ca
Subject: Estimate of % students vaccinated. Message from the President: Return to Campus planning updates
James
It is likely that the unvaccinated are over-represented among those who did not respond to the poll,
which is about half of students (there was a 53% response rate).
We thus have basically no idea what % of students are fully vaccinated except to say that it is probably between ~50% and 90%.
If we had an 80 or 90% response rate, we would have a much better estimate.
Thanks for listening,
Bernie Crespi, BISC
Preliminary results from the vaccination status survey launched on August 27 are very promising. Among respondents:
- 96.4% of faculty and staff and 90.1% of students are fully vaccinated
- 98% of faculty and staff and 95.2% of students are partially vaccinated
- 1.1% of faculty and staff and 1.8% of students cannot or are choosing not to be vaccinated
- To date, 67% of faculty and staff and 53% of students have completed the survey. The survey remains open and I encourage you to participate using the link provided in your inbox if you have not already.
In what way do the vaccination stats shared by President Johnson today indicate such a measure to be necessary? JDF
Dear President Johnson:
I simultaneously received Bulletin's from SFU and UBC. Can you please explain why UBC is implementing Mandatory
Testing, with an exemption for the vaccinated, but SFU is only suggesting it might use testing if vaccination status is undeclared or non-complete (and how does one prove this?)?
I quote from President Ono's annoucement of this afternoon:
"UBC recently announced a decision to require COVID-19 rapid testing for all students,
faculty and staff, with exemptions provided for those who are fully vaccinated against COVID-19. We would now like to provide an update.
COVID-19 rapid testing for all students, faculty,
and staff
UBC will require COVID-19 testing for all students, faculty and staff, with exemptions
provided for those who are fully vaccinated against COVID-19. A process for confidential self-disclosure of vaccination status will be implemented next week, with details provided at that time. Once the program is live, you will be asked to go online and use
your Campus Wide Login (CWL) to complete the following steps.
- You will be prompted to answer questions about your vaccination status.
- If you declare that you have been fully vaccinated, no further action will be needed.
- If you respond that you are not fully vaccinated, or prefer not to disclose your status, you will be given information about how to access rapid testing and report your results, on a recurring basis.
Members of the community without online access will be provided with a paper copy."
|
From: Joy Johnson <sfuadmin@sfu.ca>
Sent: September 2, 2021 2:15:39 PM
To: Cynthia Patton
Subject: Message from the President: Return to Campus planning updates
This message is sent on behalf of Joy Johnson, president and vice-chancellor. It has been sent to all faculty and staff.
As we approach the beginning of the fall term, we continue to prepare our campuses for the return of students, faculty and staff. It has been heartening to see groups of students taking campus tours this past week. Our return to campus plan for the fall includes layers
of protection to help keep our students, faculty, staff and visitors safe, including additional safety measures in response to the recent rise of cases in BC. We continue to work with public health to follow their
guidance on mandatory masks, declaration of vaccination status, pop-up vaccination clinics and rapid screening on campus.
We will be providing updates regularly with as much information as we have. Please keep in mind that more detail will come and that we will continue to refine protocols and respond as needed.
Vaccination is the best defense
Preliminary results from the vaccination status survey launched on August 27 are very promising. Among respondents:
- 96.4% of faculty and staff and 90.1% of students are fully vaccinated
- 98% of faculty and staff and 95.2% of students are partially vaccinated
- 1.1% of faculty and staff and 1.8% of students cannot or are choosing not to be vaccinated
To date, 67% of faculty and staff and 53% of students have completed the survey. The survey remains open and I encourage you to participate using the link provided in your inbox if you have not already.
Response to our on-campus vaccination clinics has been positive, and I am heartened to see members of our community taking this important step. More
clinics are scheduled and I encourage those who are not yet fully vaccinated to make a plan to do so. This is the most important thing you can do for your own safety and the safety of those around you. Proof of
vaccination will also be required for access to non-essential activities at SFU as we apply the BC Vaccine Card in accordance with public health.
Masks are mandatory in all indoor common spaces
You are required to wear a mask in all indoor common and learning spaces, including classrooms. Come to campus prepared with a non-medical mask. Disposable masks are also available from Student Central in Burnaby and at the information desks in Vancouver and
Surrey.
A very small number of individuals may have an approved exemption from wearing a mask.
It is important to remember that some individuals cannot wear a mask for valid medical reasons. Be kind and reserve judgement. There are processes in place to oversee mask compliance in learning spaces, including what instructors can do in the case of a student
who is not properly wearing a mask in a classroom. These processes have been provided to instructors. Individuals should not confront or challenge others regarding masks. Any questions about safety or compliance should be submitted using the COVID-19
safety reporting form.
Declaring your vaccination status
Next week we will launch a third-party website to gather vaccination status data of our campus community. The website will be accessible from your smartphone or desktop. The process is confidential, the data is secure and SFU will not have a record of your
personal information. All members of the SFU community, including, faculty, staff, students and those who plan to visit one of our campuses are required to register and make a self-declaration.
The site will ask you to enter your vaccination status. If you are fully vaccinated, that is the only step required. If you are not fully vaccinated, you will receive information on how to schedule a vaccination and get rapid screening. The website also allows
for symptom screening, and we will encourage members of the SFU community to use the site to regularly self-monitor.
We are working with public health to renew our on-campus rapid screening pilot. As we determine next steps, we will refer those who need testing to local testing centres. This element of our planning is underway and we will provide more information as we have
it.
Everyone is going at their own pace
Some will return to campus next week energized and excited; others will be managing many details in their personal lives; and some will be struggling with the current reality and the impact of the past 20 months. Be patient with one another. Look for ways to
support one another and extend compassion. You never know what someone else is dealing with, and how much kindness can help.
More information
Visit the Return to Campus website, which
is being updated this week with the latest information. Have questions about our return to campus? Email covid19@sfu.ca.
Sincerely,
Joy Johnson
Pronouns: she, her, hers
President and Vice-Chancellor
Simon Fraser University
|